sentrystr stuff

feat: prune dead zero-balance API keys with background janitor

.env.example

@@ -34,6 +34,14 @@ UPSTREAM_API_KEY=your-upstream-api-key
 # LOG_LEVEL=INFO
 # ENABLE_CONSOLE_LOGGING=true
 
+# SentryStr: mirror logs to Nostr relays (requires `pip install sentrystr`).
+# Announcements run on a background worker thread so they never block requests.
+# ENABLE_SENTRYSTR=false
+# SENTRYSTR_LOG_LEVEL=ERROR            # defaults to ERROR; keep >= LOG_LEVEL
+# SENTRYSTR_RELAYS="wss://relay.damus.io,wss://nos.lol"  # defaults to RELAYS
+# SENTRYSTR_NSEC=nsec1...              # defaults to NSEC; ephemeral key if unset
+# SENTRYSTR_RECIPIENT_NPUB=npub1...    # if set, log events are NIP-44 encrypted
+
 # Custom Model Management
 # BASE_URL=https://openrouter.ai/api/v1
 # MODELS_PATH=models.json

Makefile

@@ -98,7 +98,7 @@ docker-down:
 lint:
 	@echo "🔍 Running linting checks..."
 	$(RUFF) check .
-	$(MYPY) routstr/ --ignore-missing-imports
+	$(MYPY) .
 
 format:
 	@echo "✨ Formatting code..."
@@ -107,7 +107,7 @@ format:
 
 type-check:
 	@echo "🔎 Running type checks..."
-	$(MYPY) routstr/ --ignore-missing-imports
+	$(MYPY) .
 
 # Development setup
 dev-setup:
@@ -234,7 +234,7 @@ ci-test:
 ci-lint:
 	@echo "🤖 Running CI linting..."
 	$(RUFF) check . --exit-non-zero-on-fix
-	$(MYPY) routstr/ --ignore-missing-imports --no-error-summary
+	$(MYPY) . --no-error-summary
 
 # Debug helpers
 test-debug:

migrations/versions/b5e7c9d1f3a2_add_reserved_at_to_api_keys.py

@@ -0,0 +1,25 @@
+"""add reserved_at to api_keys
+
+Revision ID: b5e7c9d1f3a2
+Revises: a2b3c4d5e6f7
+Create Date: 2026-06-12 00:00:00.000000
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "b5e7c9d1f3a2"
+down_revision = "a2b3c4d5e6f7"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # existing keys keep NULL
+    # New reservations populate it via pay_for_request.
+    op.add_column("api_keys", sa.Column("reserved_at", sa.Integer(), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("api_keys", "reserved_at")

pyproject.toml

@@ -23,6 +23,11 @@ dependencies = [
     "litellm>=1.55.0",
 ]
 
+[project.optional-dependencies]
+# Decentralized log mirroring to Nostr relays. Enable at runtime with
+# ENABLE_SENTRYSTR=true (see routstr/core/logging.py).
+sentrystr = ["sentrystr>=0.2.0"]
+
 [dependency-groups]
 dev = [
     "mypy>=1.15.0",

routstr/auth.py

@@ -364,6 +364,7 @@ async def validate_bearer_key(
         except HTTPException:
             raise
         except Exception as e:
+            await session.rollback()
             logger.error(
                 "Cashu token redemption failed",
                 extra={
@@ -534,31 +535,19 @@ async def pay_for_request(
     )
 
     # Charge the base cost for the request atomically to avoid race conditions
+    reserved_at_now = int(time.time())
     stmt = (
         update(ApiKey)
         .where(col(ApiKey.hashed_key) == billing_key.hashed_key)
         .where(col(ApiKey.balance) - col(ApiKey.reserved_balance) >= cost_per_request)
         .values(
             reserved_balance=col(ApiKey.reserved_balance) + cost_per_request,
+            reserved_at=reserved_at_now,
             total_requests=col(ApiKey.total_requests) + 1,
         )
     )
     result = await session.exec(stmt)  # type: ignore[call-overload]
 
-    # Also increment total_requests and reserved_balance on the child key if it's different
-    if billing_key.hashed_key != key.hashed_key:
-        child_stmt = (
-            update(ApiKey)
-            .where(col(ApiKey.hashed_key) == key.hashed_key)
-            .values(
-                total_requests=col(ApiKey.total_requests) + 1,
-                reserved_balance=col(ApiKey.reserved_balance) + cost_per_request,
-            )
-        )
-        await session.exec(child_stmt)  # type: ignore[call-overload]
-
-    await session.commit()
-
     if result.rowcount == 0:
         logger.error(
             "Concurrent request depleted balance",
@@ -570,7 +559,6 @@ async def pay_for_request(
             },
         )
 
-        # Another concurrent request spent the balance first
         raise HTTPException(
             status_code=402,
             detail={
@@ -582,6 +570,44 @@ async def pay_for_request(
             },
         )
 
+    # Also increment total_requests and reserved_balance on the child key if it's different.
+    # The balance_limit guard is enforced atomically here — the Python pre-check above
+    # is a fast-path rejection only and provides no concurrency guarantee.
+    if billing_key.hashed_key != key.hashed_key:
+        child_stmt = (
+            update(ApiKey)
+            .where(col(ApiKey.hashed_key) == key.hashed_key)
+            .where(
+                (col(ApiKey.balance_limit).is_(None))
+                | (
+                    col(ApiKey.total_spent)
+                    + col(ApiKey.reserved_balance)
+                    + cost_per_request
+                    <= col(ApiKey.balance_limit)
+                )
+            )
+            .values(
+                total_requests=col(ApiKey.total_requests) + 1,
+                reserved_balance=col(ApiKey.reserved_balance) + cost_per_request,
+                reserved_at=reserved_at_now,
+            )
+        )
+        child_result = await session.exec(child_stmt)  # type: ignore[call-overload]
+
+        if child_result.rowcount == 0:
+            raise HTTPException(
+                status_code=402,
+                detail={
+                    "error": {
+                        "message": f"Balance limit exceeded: {key.balance_limit} mSats limit. {key.total_spent} already spent ({key.reserved_balance} reserved), {cost_per_request} required for this request.",
+                        "type": "insufficient_quota",
+                        "code": "balance_limit_exceeded",
+                    }
+                },
+            )
+
+    await session.commit()
+
     await session.refresh(billing_key)
     if billing_key.hashed_key != key.hashed_key:
         await session.refresh(key)
@@ -620,12 +646,19 @@ async def revert_pay_for_request(
     False if the reservation was already released (prevents negative reserved_balance)."""
     billing_key = await get_billing_key(key, session)
 
+    # Keep reserved_at while other reservations remain
+    cleared_reserved_at = case(
+        (col(ApiKey.reserved_balance) - cost_per_request > 0, col(ApiKey.reserved_at)),
+        else_=None,
+    )
+
     stmt = (
         update(ApiKey)
         .where(col(ApiKey.hashed_key) == billing_key.hashed_key)
         .where(col(ApiKey.reserved_balance) >= cost_per_request)
         .values(
             reserved_balance=col(ApiKey.reserved_balance) - cost_per_request,
+            reserved_at=cleared_reserved_at,
             total_requests=col(ApiKey.total_requests) - 1,
         )
     )
@@ -641,6 +674,7 @@ async def revert_pay_for_request(
             .values(
                 total_requests=col(ApiKey.total_requests) - 1,
                 reserved_balance=col(ApiKey.reserved_balance) - cost_per_request,
+                reserved_at=cleared_reserved_at,
             )
         )
         await session.exec(child_stmt)  # type: ignore[call-overload]
@@ -675,12 +709,18 @@ async def revert_pay_for_request(
 
 
 async def adjust_payment_for_tokens(
-    key: ApiKey, response_data: dict, session: AsyncSession, deducted_max_cost: int
+    key: ApiKey,
+    response_data: dict,
+    session: AsyncSession,
+    deducted_max_cost: int,
 ) -> dict:
     """
     Adjusts the payment based on token usage in the response.
     This is called after the initial payment and the upstream request is complete.
     Returns cost data to be included in the response.
+
+    The response's usage object is normalized with the default union parser in
+    ``calculate_cost``.
     """
     billing_key = await get_billing_key(key, session)
     model = response_data.get("model", "unknown")
@@ -763,7 +803,7 @@ async def adjust_payment_for_tokens(
                     extra={"error": str(e), "fee_msats": fee_msats},
                 )
 
-    match await calculate_cost(response_data, deducted_max_cost, session):
+    match await calculate_cost(response_data, deducted_max_cost):
         case MaxCostData() as cost:
             logger.debug(
                 "Using max cost data (no token adjustment)",
@@ -981,32 +1021,37 @@ async def adjust_payment_for_tokens(
             # actual cost exceeded discounted reservation (due to tolerance_percentage)
             if cost_difference > 0:
                 # Always release the reservation and charge min(actual_cost, balance).
-                # Using a CASE expression makes this a single atomic UPDATE — no
-                # multi-level fallback needed and balance can never go negative.
+                # CASE expressions keep this atomic and safe even when the
+                # stale-reservation sweeper has already released the reservation.
                 chargeable = case(
                     (col(ApiKey.balance) >= total_cost_msats, total_cost_msats),
                     else_=col(ApiKey.balance),
                 )
+                overrun_safe_reserved = case(
+                    (
+                        col(ApiKey.reserved_balance) >= deducted_max_cost,
+                        col(ApiKey.reserved_balance) - deducted_max_cost,
+                    ),
+                    else_=0,
+                )
 
                 finalize_stmt = (
                     update(ApiKey)
                     .where(col(ApiKey.hashed_key) == billing_key.hashed_key)
-                    .where(col(ApiKey.reserved_balance) >= deducted_max_cost)
                     .values(
-                        reserved_balance=col(ApiKey.reserved_balance) - deducted_max_cost,
+                        reserved_balance=overrun_safe_reserved,
                         balance=col(ApiKey.balance) - chargeable,
                         total_spent=col(ApiKey.total_spent) + chargeable,
                     )
                 )
-                result = await session.exec(finalize_stmt)  # type: ignore[call-overload]
+                await session.exec(finalize_stmt)  # type: ignore[call-overload]
 
                 if billing_key.hashed_key != key.hashed_key:
                     child_stmt = (
                         update(ApiKey)
                         .where(col(ApiKey.hashed_key) == key.hashed_key)
-                        .where(col(ApiKey.reserved_balance) >= deducted_max_cost)
                         .values(
-                            reserved_balance=col(ApiKey.reserved_balance) - deducted_max_cost,
+                            reserved_balance=overrun_safe_reserved,
                             total_spent=col(ApiKey.total_spent) + min(billing_key.balance, total_cost_msats),
                         )
                     )
@@ -1014,51 +1059,38 @@ async def adjust_payment_for_tokens(
 
                 await session.commit()
 
-                if result.rowcount:
-                    await session.refresh(billing_key)
-                    if billing_key.hashed_key != key.hashed_key:
-                        await session.refresh(key)
-                    cost.total_msats = total_cost_msats
-                    logger.info(
-                        "Finalized payment with additional charge",
-                        extra={
-                            "key_hash": key.hashed_key[:8] + "...",
-                            "billing_key_hash": billing_key.hashed_key[:8] + "...",
-                            "charged_amount": total_cost_msats,
-                            "new_balance": billing_key.balance,
-                            "model": model,
-                        },
-                    )
-                    await _accumulate_fee(total_cost_msats)
-                    payments_logger.info(
-                        "FINALIZE",
-                        extra={
-                            "event": "finalize",
-                            "key_hash": key.hashed_key[:8] + "...",
-                            "billing_key_hash": billing_key.hashed_key[:8] + "...",
-                            "model": model,
-                            "cost_reserved": deducted_max_cost,
-                            "cost_charged": total_cost_msats,
-                            "input_tokens": cost.input_tokens,
-                            "output_tokens": cost.output_tokens,
-                            "balance": billing_key.balance,
-                            "reserved_balance": billing_key.reserved_balance,
-                            "total_spent": billing_key.total_spent,
-                            "finalize_type": "overrun",
-                        },
-                    )
-                else:
-                    # Guard fired: reservation was already released by a concurrent
-                    # finalization for this key. Nothing left to do.
-                    logger.warning(
-                        "Finalization skipped - reservation already released",
-                        extra={
-                            "key_hash": key.hashed_key[:8] + "...",
-                            "billing_key_hash": billing_key.hashed_key[:8] + "...",
-                            "attempted_charge": total_cost_msats,
-                            "model": model,
-                        },
-                    )
+                await session.refresh(billing_key)
+                if billing_key.hashed_key != key.hashed_key:
+                    await session.refresh(key)
+                cost.total_msats = total_cost_msats
+                logger.info(
+                    "Finalized payment with additional charge",
+                    extra={
+                        "key_hash": key.hashed_key[:8] + "...",
+                        "billing_key_hash": billing_key.hashed_key[:8] + "...",
+                        "charged_amount": total_cost_msats,
+                        "new_balance": billing_key.balance,
+                        "model": model,
+                    },
+                )
+                await _accumulate_fee(total_cost_msats)
+                payments_logger.info(
+                    "FINALIZE",
+                    extra={
+                        "event": "finalize",
+                        "key_hash": key.hashed_key[:8] + "...",
+                        "billing_key_hash": billing_key.hashed_key[:8] + "...",
+                        "model": model,
+                        "cost_reserved": deducted_max_cost,
+                        "cost_charged": total_cost_msats,
+                        "input_tokens": cost.input_tokens,
+                        "output_tokens": cost.output_tokens,
+                        "balance": billing_key.balance,
+                        "reserved_balance": billing_key.reserved_balance,
+                        "total_spent": billing_key.total_spent,
+                        "finalize_type": "overrun",
+                    },
+                )
             else:
                 # Refund some of the base cost
                 refund = abs(cost_difference)
@@ -1263,3 +1295,53 @@ async def periodic_key_reset() -> None:
             break
         except Exception as e:
             logger.error(f"Error in periodic_key_reset: {e}")
+
+
+async def periodic_dead_key_prune() -> None:
+    """Periodically prune dead API keys. Interval <= 0 disables it.
+
+    See ``prune_dead_api_keys`` for eligibility.
+    """
+    from .core.db import create_session, prune_dead_api_keys
+
+    interval = settings.dead_key_prune_interval_seconds
+    if interval <= 0:
+        logger.info("Dead-key pruning disabled (interval <= 0)")
+        return
+
+    while True:
+        try:
+            await asyncio.sleep(interval)
+        except asyncio.CancelledError:
+            break
+
+        try:
+            async with create_session() as session:
+                await prune_dead_api_keys(
+                    session, settings.dead_key_min_age_seconds
+                )
+        except asyncio.CancelledError:
+            break
+        except Exception as e:
+            logger.error(f"Error in periodic_dead_key_prune: {e}")
+
+
+STALE_RESERVATION_SWEEP_INTERVAL_SECONDS: int = 60
+
+
+async def periodic_stale_reservation_sweep() -> None:
+    """Background task that releases reservations leaked by client disconnects,
+    crashes or abandoned streams.
+    """
+    from .core.db import create_session, release_stale_reservations
+
+    while True:
+        try:
+            async with create_session() as session:
+                await release_stale_reservations(
+                    session, settings.stale_reservation_timeout_seconds
+                )
+        except Exception:
+            logger.exception("Error in periodic_stale_reservation_sweep")
+
+        await asyncio.sleep(STALE_RESERVATION_SWEEP_INTERVAL_SECONDS)

routstr/balance.py

@@ -7,7 +7,7 @@ from typing import Annotated, NoReturn
 from fastapi import APIRouter, Depends, Header, HTTPException
 from fastapi.responses import JSONResponse
 from pydantic import BaseModel
-from sqlmodel import col, select, update
+from sqlmodel import col, or_, select, update
 
 from .auth import get_billing_key, validate_bearer_key
 from .core.db import (
@@ -48,7 +48,6 @@ async def get_balance_info(key: ApiKey, session: AsyncSession) -> dict:
         "balance": billing_key.total_balance,
         "reserved": billing_key.reserved_balance,
         "is_child": key.parent_key_hash is not None,
-        "parent_key": "sk-" + key.parent_key_hash if key.parent_key_hash else None,
         "total_requests": key.total_requests,
         "total_spent": key.total_spent,
         "balance_limit": key.balance_limit,
@@ -56,7 +55,9 @@ async def get_balance_info(key: ApiKey, session: AsyncSession) -> dict:
         "validity_date": key.validity_date,
     }
 
-    if not key.parent_key_hash:
+    if key.parent_key_hash:
+        info["parent_key_preview"] = key.parent_key_hash[:8] + "..."
+    else:
         # Fetch child keys if this is a parent key
         statement = select(ApiKey).where(ApiKey.parent_key_hash == key.hashed_key)
         results = await session.exec(statement)
@@ -312,9 +313,36 @@ async def refund_wallet_endpoint(
         )
 
     if key.reserved_balance > 0:
-        raise HTTPException(
-            status_code=400,
-            detail="Cannot refund key. There are ongoing requests for this api key.",
+        # Release the reservation if it is stale
+        cutoff = int(time.time()) - settings.stale_reservation_timeout_seconds
+        stale_release_stmt = (
+            update(ApiKey)
+            .where(col(ApiKey.hashed_key) == key.hashed_key)
+            .where(col(ApiKey.reserved_balance) > 0)
+            .where(
+                or_(
+                    col(ApiKey.reserved_at).is_(None),
+                    col(ApiKey.reserved_at) < cutoff,
+                )
+            )
+            .values(reserved_balance=0, reserved_at=None)
+        )
+        stale_result = await session.exec(stale_release_stmt)  # type: ignore[call-overload]
+        await session.commit()
+
+        if stale_result.rowcount == 0:
+            raise HTTPException(
+                status_code=400,
+                detail="Cannot refund key. There are ongoing requests for this api key.",
+            )
+
+        await session.refresh(key)
+        logger.warning(
+            "refund_wallet_endpoint: released stale reservation before refund",
+            extra={
+                "hashed_key": key.hashed_key,
+                "stale_timeout_seconds": settings.stale_reservation_timeout_seconds,
+            },
         )
 
     remaining_balance_msats: int = key.total_balance
@@ -341,7 +369,7 @@ async def refund_wallet_endpoint(
         .where(col(ApiKey.hashed_key) == key.hashed_key)
         .where(col(ApiKey.balance) == pre_debit_balance)
         .where(col(ApiKey.reserved_balance) == pre_debit_reserved)
-        .values(balance=0, reserved_balance=0)
+        .values(balance=0, reserved_balance=0, reserved_at=None)
     )
     debit_result = await session.exec(debit_stmt)  # type: ignore[call-overload]
     await session.commit()

routstr/core/db.py

@@ -9,9 +9,10 @@ from typing import AsyncGenerator
 from alembic import command
 from alembic.config import Config
 from alembic.util.exc import CommandError
-from sqlalchemy import UniqueConstraint
+from sqlalchemy import UniqueConstraint, delete
 from sqlalchemy.exc import OperationalError
 from sqlalchemy.ext.asyncio.engine import create_async_engine
+from sqlalchemy.orm import aliased
 from sqlmodel import Field, Relationship, SQLModel, col, func, select, update
 from sqlmodel.ext.asyncio.session import AsyncSession
 
@@ -33,6 +34,14 @@ class ApiKey(SQLModel, table=True):  # type: ignore
     reserved_balance: int = Field(
         default=0, description="Reserved balance in millisatoshis (msats)"
     )
+    reserved_at: int | None = Field(
+        default=None,
+        description=(
+            "Unix timestamp of the most recent balance reservation. Used to "
+            "detect and release stale reservations (e.g. after client "
+            "disconnects). NULL when no reservation has been made yet."
+        ),
+    )
     refund_address: str | None = Field(
         default=None,
         description="Lightning address to refund remaining balance after key expires",
@@ -87,12 +96,93 @@ class ApiKey(SQLModel, table=True):  # type: ignore
 
 
 async def reset_all_reserved_balances(session: AsyncSession) -> None:
-    stmt = update(ApiKey).values(reserved_balance=0)
+    stmt = update(ApiKey).values(reserved_balance=0, reserved_at=None)
     await session.exec(stmt)  # type: ignore[call-overload]
     await session.commit()
     logger.info("Reset reserved balances on startup")
 
 
+async def release_stale_reservations(
+    session: AsyncSession, max_age_seconds: int
+) -> int:
+    """Release reservations whose last reserve is older than max_age_seconds.
+    """
+    cutoff = int(time.time()) - max_age_seconds
+    stmt = (
+        update(ApiKey)
+        .where(col(ApiKey.reserved_balance) > 0)
+        .where(col(ApiKey.reserved_at).is_not(None))
+        .where(col(ApiKey.reserved_at) < cutoff)
+        .values(reserved_balance=0, reserved_at=None)
+    )
+    result = await session.exec(stmt)  # type: ignore[call-overload]
+    await session.commit()
+    released = int(result.rowcount or 0)
+    if released:
+        logger.warning(
+            "Released stale balance reservations",
+            extra={"released_keys": released, "max_age_seconds": max_age_seconds},
+        )
+    return released
+
+
+async def prune_dead_api_keys(session: AsyncSession, min_age_seconds: int) -> int:
+    """Delete dead parentless API keys; return the count removed.
+
+    Dead = 0 balance/reservation/spend/requests, older than the grace period,
+    no parent, no children, no pending invoice. Cashu rows are unlinked (not
+    deleted) first to keep the audit trail.
+    """
+    cutoff = int(time.time()) - min_age_seconds
+
+    child = aliased(ApiKey)
+    has_children = (
+        select(child.hashed_key).where(
+            col(child.parent_key_hash) == col(ApiKey.hashed_key)
+        )
+    ).exists()
+    pending_invoice = (
+        select(LightningInvoice.id)
+        .where(col(LightningInvoice.api_key_hash) == col(ApiKey.hashed_key))
+        .where(col(LightningInvoice.status) == "pending")
+    ).exists()
+
+    eligible_hashes = (
+        select(ApiKey.hashed_key)
+        .where(col(ApiKey.balance) == 0)
+        .where(col(ApiKey.reserved_balance) == 0)
+        .where(col(ApiKey.total_spent) == 0)
+        .where(col(ApiKey.total_requests) == 0)
+        .where(col(ApiKey.parent_key_hash).is_(None))
+        .where(
+            (col(ApiKey.created_at).is_(None)) | (col(ApiKey.created_at) < cutoff)
+        )
+        .where(~pending_invoice)
+        .where(~has_children)
+    )
+
+    # Unlink transactions rather than cascade-deleting them, so the financial
+    # audit trail survives. The eligibility predicate is re-evaluated inside both
+    # statements so a key that gained balance mid-run is left untouched.
+    await session.exec(  # type: ignore[call-overload]
+        update(CashuTransaction)
+        .where(col(CashuTransaction.api_key_hashed_key).in_(eligible_hashes))
+        .values(api_key_hashed_key=None)
+    )
+
+    result = await session.exec(  # type: ignore[call-overload]
+        delete(ApiKey).where(col(ApiKey.hashed_key).in_(eligible_hashes))
+    )
+    await session.commit()
+
+    pruned = int(result.rowcount or 0)
+    logger.info(
+        "Pruned dead API keys",
+        extra={"pruned_keys": pruned, "min_age_seconds": min_age_seconds},
+    )
+    return pruned
+
+
 class ModelRow(SQLModel, table=True):  # type: ignore
     __tablename__ = "models"
     id: str = Field(primary_key=True)

routstr/core/exceptions.py

@@ -7,11 +7,26 @@ logger = get_logger(__name__)
 
 
 class UpstreamError(Exception):
-    """Exception raised when an upstream provider fails."""
+    """Exception raised when an upstream provider fails.
 
-    def __init__(self, message: str, status_code: int = 502):
+    ``code`` carries a stable, machine-readable classification (e.g.
+    ``UPSTREAM_RATE_LIMIT``) so callers can distinguish failure kinds without
+    string-matching the message. ``details`` holds optional structured,
+    redaction-safe context. Both default to ``None`` for backwards
+    compatibility.
+    """
+
+    def __init__(
+        self,
+        message: str,
+        status_code: int = 502,
+        code: str | None = None,
+        details: dict[str, object] | None = None,
+    ):
         self.message = message
         self.status_code = status_code
+        self.code = code
+        self.details = details
         super().__init__(message)
 
 

routstr/core/logging.py

@@ -51,6 +51,8 @@ from pythonjsonlogger import jsonlogger
 from rich.console import Console
 from rich.logging import RichHandler
 
+from .redaction import redact_obj, redact_org_ids
+
 # Only use RichHandler when stdout is a real TTY. In non-TTY contexts
 # (docker logs, pipes, CI) Rich pads every line to width and wraps long
 # records, producing visually-empty trailing whitespace and split records.
@@ -180,6 +182,37 @@ class RequestIdFilter(logging.Filter):
         return True
 
 
+# Standard ``LogRecord`` attributes that are never user-supplied ``extra``
+# fields; skipped when redacting structured extras (``msg``/``message`` are
+# handled separately above).
+_NON_EXTRA_RECORD_ATTRS = frozenset(
+    {
+        "name",
+        "msg",
+        "args",
+        "levelname",
+        "levelno",
+        "pathname",
+        "filename",
+        "module",
+        "exc_info",
+        "exc_text",
+        "stack_info",
+        "lineno",
+        "funcName",
+        "created",
+        "msecs",
+        "relativeCreated",
+        "thread",
+        "threadName",
+        "processName",
+        "process",
+        "taskName",
+        "message",
+    }
+)
+
+
 class SecurityFilter(logging.Filter):
     """Filter to remove sensitive information from logs."""
 
@@ -199,31 +232,57 @@ class SecurityFilter(logging.Filter):
         "refund_address",
     }
 
+    def _scrub(self, message: str) -> str:
+        """Redact secrets from a single string."""
+        standalone_patterns = [
+            r"Bearer\s+([a-zA-Z0-9_\-\.]{10,})",  # Bearer token (must be 10 characters or more to reduce false-positives)
+            r"cashu[A-Z]+([a-zA-Z0-9_\-\.=/+]+)",  # Cashu tokens
+            r"nsec[a-z0-9]+",  # Nostr Public / Private Key
+        ]
+        for pattern in standalone_patterns:
+            message = re.sub(pattern, "[REDACTED]", message, flags=re.IGNORECASE)
+
+        for key in self.SENSITIVE_KEYS:
+            if key in message.lower():
+                key_patterns = [
+                    rf"{key}\s*[:=]\s*([a-zA-Z0-9_\-\.=/+]+)",  # key:value or key=value (including any variant with spaces)
+                    rf'{key}\s*[:=]\s*["\']([^"\']+)["\']',  # key:"value" or key='value' (including any variant with spaces)
+                ]
+                for pattern in key_patterns:
+                    message = re.sub(
+                        pattern, f"{key}: [REDACTED]", message, flags=re.IGNORECASE
+                    )
+        return message
+
     def filter(self, record: logging.LogRecord) -> bool:
         """Filter out sensitive information from log records."""
         try:
-            message = record.getMessage()
-            standalone_patterns = [
-                r"Bearer\s+([a-zA-Z0-9_\-\.]{10,})",  # Bearer token (must be 10 characters or more to reduce false-positives)
-                r"cashu[A-Z]+([a-zA-Z0-9_\-\.=/+]+)",  # Cashu tokens
-                r"nsec[a-z0-9]+",  # Nostr Public / Private Key
-            ]
-            for pattern in standalone_patterns:
-                message = re.sub(pattern, "[REDACTED]", message, flags=re.IGNORECASE)
-
-            for key in self.SENSITIVE_KEYS:
-                if key in message.lower():
-                    key_patterns = [
-                        rf"{key}\s*[:=]\s*([a-zA-Z0-9_\-\.=/+]+)",  # key:value or key=value (including any variant with spaces)
-                        rf'{key}\s*[:=]\s*["\']([^"\']+)["\']',  # key:"value" or key='value' (including any variant with spaces)
-                    ]
-                    for pattern in key_patterns:
-                        message = re.sub(
-                            pattern, f"{key}: [REDACTED]", message, flags=re.IGNORECASE
-                        )
-            record.msg = message
+            message = redact_org_ids(record.getMessage())
+            record.msg = self._scrub(message)
             record.args = ()
 
+            # The exception traceback is appended by the *formatter* (e.g. when a
+            # QueueHandler flattens the record before it is announced to the
+            # public, permanent SentryStr relays), so the message scrub above
+            # never sees it. Pre-render and redact it here and cache the result
+            # in `exc_text` so every formatter reuses the scrubbed version.
+            if record.exc_info and record.exc_info[0] is not None and not record.exc_text:
+                record.exc_text = logging.Formatter().formatException(record.exc_info)
+            if record.exc_text:
+                record.exc_text = self._scrub(redact_org_ids(record.exc_text))
+            if record.stack_info:
+                record.stack_info = self._scrub(redact_org_ids(record.stack_info))
+
+            # Structured `extra={...}` fields are emitted by the JSON formatter
+            # straight from the record dict and never pass through the message
+            # formatting above. Redact organization IDs from any string-valued
+            # extra so they cannot leak via structured logs.
+            for attr, value in list(record.__dict__.items()):
+                if attr in _NON_EXTRA_RECORD_ATTRS:
+                    continue
+                if isinstance(value, (str, dict, list, tuple)):
+                    record.__dict__[attr] = redact_obj(value)
+
         except Exception:
             pass
 
@@ -408,6 +467,120 @@ def setup_logging() -> None:
 
     logging.config.dictConfig(LOGGING_CONFIG)
 
+    _install_sentrystr_logging(LOGGING_CONFIG)
+
+
+# Handle for the background SentryStr logging worker (None when disabled).
+_sentrystr_handle: Any = None
+
+# Bound on the in-memory queue feeding the background SentryStr worker. Records
+# beyond this are dropped rather than blocking the caller or growing memory
+# without limit when a relay is slow or unreachable.
+_SENTRYSTR_QUEUE_SIZE = 10_000
+
+# Max seconds to wait for the queued backlog to flush on shutdown before
+# abandoning it, so shutdown cannot hang on a slow or unreachable relay.
+_SENTRYSTR_SHUTDOWN_TIMEOUT = 10.0
+
+
+def _install_sentrystr_logging(logging_config: dict[str, Any]) -> None:
+    """Mirror routstr application logs to Nostr relays via SentryStr.
+
+    Announcing to relays blocks, so SentryStr's installer runs the publish on a
+    dedicated background worker thread fed by an in-memory queue; the request /
+    event-loop threads only pay the cost of enqueueing a record. Disabled unless
+    `ENABLE_SENTRYSTR` is set. Any failure here is swallowed so optional logging
+    can never take down startup.
+    """
+    global _sentrystr_handle
+
+    if _sentrystr_handle is not None:
+        return
+
+    try:
+        from .settings import settings
+    except Exception:
+        return
+
+    if not getattr(settings, "enable_sentrystr", False):
+        return
+
+    routstr_logger = logging.getLogger("routstr")
+
+    relays = list(settings.sentrystr_relays or settings.relays or [])
+    if not relays:
+        routstr_logger.warning(
+            "SentryStr logging is enabled but no relays are configured; set "
+            "SENTRYSTR_RELAYS or RELAYS. Skipping SentryStr logging."
+        )
+        return
+
+    try:
+        from sentrystr import install_sentrystr_logging
+    except Exception:
+        routstr_logger.warning(
+            "SentryStr logging is enabled but the `sentrystr` package is not "
+            "installed. Install it with `pip install sentrystr`. Skipping "
+            "SentryStr logging."
+        )
+        return
+
+    # Default to ERROR: these events are announced to public, permanent relays,
+    # so only genuine problems should be mirrored unless the operator opts into
+    # something more verbose via SENTRYSTR_LOG_LEVEL. (Keep this at or above
+    # LOG_LEVEL; a lower value is gated out by the routstr loggers' own level.)
+    level = (settings.sentrystr_log_level or "ERROR").upper()
+
+    # routstr application loggers set propagate=False, so the handler must be
+    # attached to each of them rather than relying on propagation to the root.
+    routstr_loggers = [
+        name
+        for name in logging_config.get("loggers", {})
+        if name == "routstr" or name.startswith("routstr.")
+    ] or ["routstr"]
+
+    try:
+        _sentrystr_handle = install_sentrystr_logging(
+            relays=relays,
+            private_key=(settings.sentrystr_nsec or settings.nsec or None),
+            level=level,
+            loggers=routstr_loggers,
+            recipient_pubkey=(settings.sentrystr_recipient_npub or None),
+            platform="routstr",
+            formatter=logging.Formatter("%(message)s"),
+            # Run the same scrubbing/enrichment filters used by the other
+            # handlers, on the calling thread, before records are handed to the
+            # background worker. RequestIdFilter must run here because it reads a
+            # ContextVar that is only set on the request thread; SecurityFilter
+            # must run here so secrets are redacted before anything is announced
+            # to the (public, permanent) relays. Passing them to the installer
+            # attaches them before the handler goes live, so no record can slip
+            # through unfiltered during startup.
+            filters=[RequestIdFilter(), SecurityFilter()],
+            # Bound the queue so a slow/unreachable relay can't grow memory.
+            queue_size=_SENTRYSTR_QUEUE_SIZE,
+        )
+    except Exception as exc:
+        routstr_logger.warning("Failed to initialize SentryStr logging: %s", exc)
+        return
+
+    routstr_logger.info(
+        "SentryStr logging enabled",
+        extra={"sentrystr_level": level, "sentrystr_relay_count": len(relays)},
+    )
+
+
+def shutdown_sentrystr_logging() -> None:
+    """Flush and stop the background SentryStr logging worker, if running."""
+    global _sentrystr_handle
+    handle = _sentrystr_handle
+    _sentrystr_handle = None
+    if handle is not None:
+        try:
+            handle.close(timeout=_SENTRYSTR_SHUTDOWN_TIMEOUT)
+        except Exception:
+            pass
+
 
 def get_logger(name: str) -> logging.Logger:
     """Get a logger instance for the given module name."""

routstr/core/main.py

@@ -11,7 +11,11 @@ from starlette.exceptions import HTTPException
 from starlette.responses import Response as StarletteResponse
 from starlette.types import Scope
 
-from ..auth import periodic_key_reset
+from ..auth import (
+    periodic_dead_key_prune,
+    periodic_key_reset,
+    periodic_stale_reservation_sweep,
+)
 from ..balance import balance_router, deprecated_wallet_router
 from ..lightning import lightning_router, periodic_invoice_watcher
 from ..nostr import (
@@ -24,6 +28,7 @@ from ..payment.models import models_router, update_sats_pricing
 from ..payment.price import update_prices_periodically
 from ..proxy import initialize_upstreams, proxy_router, refresh_model_maps_periodically
 from ..upstream.auto_topup import periodic_auto_topup
+from ..upstream.deepseek_v4_pricing_shim import register_deepseek_v4_pricing
 from ..upstream.litellm_routing import configure_litellm
 from ..wallet import periodic_payout, periodic_refund_sweep, periodic_routstr_fee_payout
 from .admin import admin_router
@@ -54,6 +59,8 @@ async def lifespan(_: FastAPI) -> AsyncGenerator[None, None]:
     models_refresh_task = None
     model_maps_refresh_task = None
     key_reset_task = None
+    stale_reservation_task = None
+    dead_key_prune_task = None
     auto_topup_task = None
     refund_sweep_task = None
     routstr_fee_task = None
@@ -64,6 +71,11 @@ async def lifespan(_: FastAPI) -> AsyncGenerator[None, None]:
         # debug logging) before any upstream provider dispatches a request.
         configure_litellm()
 
+        # TEMPORARY: backfill DeepSeek V4 pricing missing from litellm's cost
+        # map (BerriAI/litellm#30430). Remove this call and
+        # deepseek_v4_pricing_shim.py once litellm ships these models.
+        register_deepseek_v4_pricing()
+
         # Run database migrations on startup
         run_migrations()
 
@@ -122,6 +134,10 @@ async def lifespan(_: FastAPI) -> AsyncGenerator[None, None]:
         if global_settings.providers_refresh_interval_seconds > 0:
             providers_task = asyncio.create_task(providers_cache_refresher())
         key_reset_task = asyncio.create_task(periodic_key_reset())
+        stale_reservation_task = asyncio.create_task(
+            periodic_stale_reservation_sweep()
+        )
+        dead_key_prune_task = asyncio.create_task(periodic_dead_key_prune())
         auto_topup_task = asyncio.create_task(periodic_auto_topup())
         refund_sweep_task = asyncio.create_task(periodic_refund_sweep())
         routstr_fee_task = asyncio.create_task(periodic_routstr_fee_payout())
@@ -159,6 +175,10 @@ async def lifespan(_: FastAPI) -> AsyncGenerator[None, None]:
             model_maps_refresh_task.cancel()
         if key_reset_task is not None:
             key_reset_task.cancel()
+        if stale_reservation_task is not None:
+            stale_reservation_task.cancel()
+        if dead_key_prune_task is not None:
+            dead_key_prune_task.cancel()
         if auto_topup_task is not None:
             auto_topup_task.cancel()
         if refund_sweep_task is not None:
@@ -188,6 +208,10 @@ async def lifespan(_: FastAPI) -> AsyncGenerator[None, None]:
                 tasks_to_wait.append(model_maps_refresh_task)
             if key_reset_task is not None:
                 tasks_to_wait.append(key_reset_task)
+            if stale_reservation_task is not None:
+                tasks_to_wait.append(stale_reservation_task)
+            if dead_key_prune_task is not None:
+                tasks_to_wait.append(dead_key_prune_task)
             if auto_topup_task is not None:
                 tasks_to_wait.append(auto_topup_task)
             if refund_sweep_task is not None:
@@ -206,6 +230,13 @@ async def lifespan(_: FastAPI) -> AsyncGenerator[None, None]:
                 extra={"error": str(e), "error_type": type(e).__name__},
             )
 
+        # Flush and stop the background SentryStr logging worker (no-op when
+        # SentryStr logging is disabled). Run off the event loop: the drain is
+        # blocking (though bounded) and must not stall the loop during shutdown.
+        from .logging import shutdown_sentrystr_logging
+
+        await asyncio.to_thread(shutdown_sentrystr_logging)
+
 
 class _ImmutableStaticFiles(StaticFiles):
     """Static files with long Cache-Control for content-hashed Next.js assets.
@@ -355,7 +386,10 @@ if UI_DIST_PATH.exists() and UI_DIST_PATH.is_dir():
 
 else:
     logger.warning(
-        f"UI dist directory not found at {UI_DIST_PATH}, skipping static file serving"
+        "UI dist directory not found at %s; serving API only. Run `make ui-build` "
+        "to build the static UI served from here, or `make ui-dev` for the Next.js "
+        "dev server with hot reload on :3000 (it targets this backend on :8000).",
+        UI_DIST_PATH,
     )
 
     @app.get("/", include_in_schema=False)

routstr/core/redaction.py

@@ -0,0 +1,51 @@
+"""Redaction helpers for sensitive provider identifiers.
+
+Single source of truth for stripping account-scoped identifiers (e.g. OpenAI
+organization IDs) from any text before it is logged, returned to a caller, or
+written to an audit entry.
+"""
+
+from __future__ import annotations
+
+import re
+from typing import Any
+
+# OpenAI-style organization identifiers look like ``org-<base62>``. Require at
+# least 6 trailing chars so the already-redacted literal ``org-[REDACTED]`` is
+# never re-matched (``[`` is not in the character class).
+_ORG_ID_PATTERN = re.compile(r"\borg-[A-Za-z0-9]{6,}\b")
+
+ORG_ID_PLACEHOLDER = "org-[REDACTED]"
+
+
+def redact_org_ids(text: str) -> str:
+    """Replace OpenAI-style organization IDs with ``org-[REDACTED]``.
+
+    Args:
+        text: Arbitrary text that may embed an ``org-*`` identifier.
+
+    Returns:
+        The text with every organization ID replaced. Non-string input is
+        returned unchanged after coercion to ``str``.
+    """
+    if not text:
+        return text
+    return _ORG_ID_PATTERN.sub(ORG_ID_PLACEHOLDER, text)
+
+
+def redact_obj(obj: Any) -> Any:
+    """Recursively redact organization IDs in arbitrary nested structures.
+
+    Strings are redacted in place; dicts and lists/tuples are walked so that
+    identifiers nested inside structured payloads (e.g. log ``extra`` fields or
+    error ``details``) are also stripped. Other types are returned unchanged.
+    """
+    if isinstance(obj, str):
+        return redact_org_ids(obj)
+    if isinstance(obj, dict):
+        return {key: redact_obj(value) for key, value in obj.items()}
+    if isinstance(obj, list):
+        return [redact_obj(value) for value in obj]
+    if isinstance(obj, tuple):
+        return tuple(redact_obj(value) for value in obj)
+    return obj

routstr/core/settings.py

@@ -16,7 +16,12 @@ class Settings(BaseSettings):
 
         @classmethod
         def parse_env_var(cls, field_name: str, raw_value: str) -> Any:  # type: ignore[override]
-            if field_name in {"cashu_mints", "cors_origins", "relays"}:
+            if field_name in {
+                "cashu_mints",
+                "cors_origins",
+                "relays",
+                "sentrystr_relays",
+            }:
                 v = str(raw_value).strip()
                 if v == "":
                     return []
@@ -67,6 +72,20 @@ class Settings(BaseSettings):
     reset_reserved_balance_on_startup: bool = Field(
         default=True, env="RESET_RESERVED_BALANCE_ON_STARTUP"
     )  # deactivate in horizontal scaling setups
+    # Reservations older than this are considered leaked (client disconnect,
+    # crash, abandoned stream) and released by the background sweeper and the
+    # refund endpoint.
+    stale_reservation_timeout_seconds: int = Field(
+        default=300, env="STALE_RESERVATION_TIMEOUT_SECONDS"
+    )
+    # Background prune of dead (zero balance, never used) API keys.
+    # Interval 0 disables it; min-age is a grace period (default 1 week).
+    dead_key_prune_interval_seconds: int = Field(
+        default=3600, env="DEAD_KEY_PRUNE_INTERVAL_SECONDS"
+    )
+    dead_key_min_age_seconds: int = Field(
+        default=604_800, env="DEAD_KEY_MIN_AGE_SECONDS"
+    )
 
     # Network
     cors_origins: list[str] = Field(default_factory=lambda: ["*"], env="CORS_ORIGINS")
@@ -89,6 +108,21 @@ class Settings(BaseSettings):
     log_level: str = Field(default="INFO", env="LOG_LEVEL")
     enable_console_logging: bool = Field(default=True, env="ENABLE_CONSOLE_LOGGING")
 
+    # SentryStr (decentralized logging to Nostr relays). When enabled, routstr
+    # application logs at `sentrystr_log_level` and above are mirrored to Nostr
+    # relays on a background worker thread (see routstr/core/logging.py).
+    enable_sentrystr: bool = Field(default=False, env="ENABLE_SENTRYSTR")
+    # Minimum level forwarded to relays. Empty -> defaults to ERROR. Should be
+    # at or above `log_level`, since the routstr loggers gate lower records.
+    sentrystr_log_level: str = Field(default="", env="SENTRYSTR_LOG_LEVEL")
+    # Relays to announce to. Empty -> fall back to the discovery `relays`.
+    sentrystr_relays: list[str] = Field(default_factory=list, env="SENTRYSTR_RELAYS")
+    # Secret key (nsec or hex) used to sign log events. Empty -> fall back to
+    # `nsec`; if that is also empty an ephemeral key is generated per process.
+    sentrystr_nsec: str = Field(default="", env="SENTRYSTR_NSEC")
+    # Optional recipient npub. When set, log events are NIP-44 encrypted to it.
+    sentrystr_recipient_npub: str = Field(default="", env="SENTRYSTR_RECIPIENT_NPUB")
+
     # Other
     chat_completions_api_version: str = Field(
         default="", env="CHAT_COMPLETIONS_API_VERSION"

routstr/payment/cost_calculation.py

@@ -3,9 +3,17 @@ import math
 from pydantic.v1 import BaseModel
 
 from ..core import get_logger
-from ..core.db import AsyncSession
 from ..core.settings import settings
 from .price import sats_usd_price
+from .usage import normalize_usage, parse_token_count
+
+__all__ = [
+    "CostData",
+    "CostDataError",
+    "MaxCostData",
+    "calculate_cost",
+    "parse_token_count",
+]
 
 logger = get_logger(__name__)
 
@@ -34,7 +42,8 @@ class CostDataError(BaseModel):
 
 
 async def calculate_cost(
-    response_data: dict, max_cost: int, session: AsyncSession
+    response_data: dict,
+    max_cost: int,
 ) -> CostData | MaxCostData | CostDataError:
     """Calculate the cost of an API request based on token usage.
 
@@ -44,6 +53,9 @@ async def calculate_cost(
 
     Returns:
         Cost data or error information
+
+    The response's usage object is normalized with the default union parser;
+    this function holds no vendor-dialect knowledge of its own.
     """
     logger.debug(
         "Starting cost calculation",
@@ -54,8 +66,9 @@ async def calculate_cost(
         },
     )
 
-    # Check for usage data
-    if "usage" not in response_data or response_data["usage"] is None:
+    usage = normalize_usage(response_data.get("usage"))
+
+    if usage is None:
         logger.warning(
             "No usage data in response — billing at MaxCostData with zero "
             "tokens. Dashboard will show this request as `(0+0)`. Most "
@@ -84,16 +97,14 @@ async def calculate_cost(
             cache_creation_msats=0,
         )
 
-    usage_data = response_data["usage"]
+    usage_data = response_data.get("usage") or {}
+    if not isinstance(usage_data, dict):
+        usage_data = {}
 
-    # Extract token counts
-    input_tokens = _extract_token_pair(usage_data, "prompt_tokens", "input_tokens")
-    output_tokens = _extract_token_pair(usage_data, "completion_tokens", "output_tokens")
-
-    # Extract cache tokens (handles OpenAI vs Anthropic formats)
-    cache_read_tokens, cache_creation_tokens, input_tokens = _extract_cache_tokens(
-        usage_data, input_tokens
-    )
+    input_tokens = usage.input_tokens
+    output_tokens = usage.output_tokens
+    cache_read_tokens = usage.cache_read_tokens
+    cache_creation_tokens = usage.cache_write_tokens
 
     # Try USD cost first
     usd_cost = _resolve_usd_cost(usage_data, response_data)
@@ -202,22 +213,6 @@ async def calculate_cost(
 # ============================================================================
 
 
-def parse_token_count(value: object) -> int:
-    """Parse a token count from various formats (int, float, str, bool)."""
-    if isinstance(value, bool):
-        return 0
-    if isinstance(value, int):
-        return max(0, value)
-    if isinstance(value, float):
-        return max(0, int(value))
-    if isinstance(value, str):
-        try:
-            return max(0, int(float(value)))
-        except ValueError:
-            return 0
-    return 0
-
-
 def _coerce_usd(value: object) -> float:
     """Coerce a value to USD float, handling various formats safely."""
     if value is None or isinstance(value, bool):
@@ -230,37 +225,6 @@ def _coerce_usd(value: object) -> float:
         return 0.0
 
 
-def _extract_token_pair(
-    usage_data: dict, standard_field: str, alt_field: str
-) -> int:
-    """Extract token count trying two field names in order."""
-    value = parse_token_count(usage_data.get(standard_field, 0))
-    if value > 0:
-        return value
-    return parse_token_count(usage_data.get(alt_field, 0))
-
-
-def _extract_cache_tokens(usage_data: dict, input_tokens: int) -> tuple[int, int, int]:
-    """Extract cache tokens, handling OpenAI vs Anthropic formats.
-
-    Returns: (cache_read_tokens, cache_creation_tokens, adjusted_input_tokens)
-    """
-    cache_read = parse_token_count(usage_data.get("cache_read_input_tokens", 0))
-    cache_creation = parse_token_count(
-        usage_data.get("cache_creation_input_tokens", 0)
-    )
-
-    # OpenAI: cache is included in input_tokens, subtract it
-    prompt_details = usage_data.get("prompt_tokens_details")
-    if isinstance(prompt_details, dict) and not cache_read:
-        openai_cached = parse_token_count(prompt_details.get("cached_tokens", 0))
-        if openai_cached:
-            cache_read = openai_cached
-            input_tokens = max(0, input_tokens - cache_read)
-
-    return cache_read, cache_creation, input_tokens
-
-
 def _resolve_usd_cost(usage_data: dict, response_data: dict) -> float:
     """Resolve USD cost with clear priority order.
 
@@ -454,10 +418,21 @@ def _calculate_from_tokens(
         },
     )
 
+    # Fold the cache-read/write cost into the visible ``input_msats`` so a
+    # dashboard that renders I / O / T sees ``input + output == total``
+    # exactly. This mirrors ``_fold_cache_into_input_tokens`` (which rolls the
+    # cache token counts into the visible prompt total). The standalone
+    # ``cache_read_msats`` / ``cache_creation_msats`` fields stay populated for
+    # clients that want the breakdown; nothing sums the components to derive
+    # ``total_msats`` (it is computed independently above), so this is
+    # display-only and does not change what is billed.
+    visible_output_msats = int(calc_output_msats)
+    visible_input_msats = token_based_cost - visible_output_msats
+
     return CostData(
         base_msats=0,
-        input_msats=int(calc_input_msats),
-        output_msats=int(calc_output_msats),
+        input_msats=visible_input_msats,
+        output_msats=visible_output_msats,
         total_msats=token_based_cost,
         total_usd=total_usd,
         input_tokens=input_tokens,

routstr/payment/helpers.py

@@ -11,6 +11,8 @@ from PIL import Image
 from sqlmodel.ext.asyncio.session import AsyncSession
 
 from ..core import get_logger
+from ..core.exceptions import UpstreamError
+from ..core.redaction import redact_org_ids
 from ..core.settings import settings
 from ..wallet import deserialize_token_from_string
 
@@ -418,16 +420,27 @@ def create_error_response(
     status_code: int,
     request: Request,
     token: str | None = None,
+    code: str | int | None = None,
+    details: dict[str, object] | None = None,
 ) -> Response:
-    """Create a standardized error response."""
+    """Create a standardized error response.
+
+    ``code`` is a stable, machine-readable classification (e.g.
+    ``UPSTREAM_RATE_LIMIT``); when omitted it defaults to the HTTP status code
+    for backwards compatibility. ``details`` carries optional structured,
+    redaction-safe context.
+    """
+    error_obj: dict[str, object] = {
+        "message": redact_org_ids(message),
+        "type": error_type,
+        "code": code if code is not None else status_code,
+    }
+    if details is not None:
+        error_obj["details"] = details
     return Response(
         content=json.dumps(
             {
-                "error": {
-                    "message": message,
-                    "type": error_type,
-                    "code": status_code,
-                },
+                "error": error_obj,
                 "request_id": getattr(request.state, "request_id", "unknown"),
             }
         ),
@@ -435,3 +448,20 @@ def create_error_response(
         media_type="application/json",
         headers={"X-Cashu": token} if token else {},
     )
+
+
+def create_upstream_error_response(
+    error: UpstreamError,
+    request: Request,
+    fallback_status: int = 502,
+) -> Response:
+    """Build an error response from an :class:`UpstreamError`, preserving its
+    structured ``code``, ``details``, and original ``status_code``."""
+    return create_error_response(
+        "upstream_error",
+        str(error),
+        error.status_code or fallback_status,
+        request=request,
+        code=getattr(error, "code", None),
+        details=getattr(error, "details", None),
+    )

routstr/payment/models.py

@@ -85,6 +85,48 @@ class Model(BaseModel):
         return hash(self.id)
 
 
+def backfill_cache_pricing(model_id: str, pricing: Pricing) -> Pricing:
+    """Fill missing cache rates from litellm's bundled cost map.
+
+    The OpenRouter model feed omits ``input_cache_read``/``input_cache_write``
+    for many models (most DeepSeek entries, openai/gpt-4o, ...). Without a
+    cache rate, billing falls back to the full input rate, which overcharges
+    cache reads (DeepSeek hits are 10x cheaper) and undercharges Anthropic
+    cache writes (1.25x). litellm ships per-model USD rates keyed by the exact
+    OpenRouter id (deepseek/deepseek-chat) or by the bare model name
+    (gpt-4o, claude-sonnet-4-5), so both spellings are tried.
+
+    Rates already present (e.g. provided by OpenRouter) are authoritative and
+    never overwritten. Unknown models are returned unchanged.
+    """
+    needs_read = (pricing.input_cache_read or 0.0) <= 0.0
+    needs_write = (pricing.input_cache_write or 0.0) <= 0.0
+    if not (needs_read or needs_write):
+        return pricing
+
+    import litellm
+
+    info: dict | None = None
+    for key in (model_id, model_id.split("/", 1)[-1]):
+        candidate = litellm.model_cost.get(key)
+        if isinstance(candidate, dict):
+            info = candidate
+            break
+    if info is None:
+        return pricing
+
+    updated = Pricing.parse_obj(pricing.dict())
+    if needs_read:
+        read_rate = info.get("cache_read_input_token_cost")
+        if isinstance(read_rate, (int, float)) and read_rate > 0:
+            updated.input_cache_read = float(read_rate)
+    if needs_write:
+        write_rate = info.get("cache_creation_input_token_cost")
+        if isinstance(write_rate, (int, float)) and write_rate > 0:
+            updated.input_cache_write = float(write_rate)
+    return updated
+
+
 def _has_valid_pricing(model: dict) -> bool:
     """Check if model has valid pricing (not free, no negative values)."""
     pricing = model.get("pricing", {})

routstr/payment/usage.py

@@ -0,0 +1,131 @@
+"""Vendor-agnostic normalization of upstream usage objects.
+
+Upstream providers report token usage in vendor dialects that differ in field
+names and in whether cached tokens are included in the input count:
+
+* OpenAI / Azure / xAI / Groq / Moonshot / Qwen / Gemini-compat: cache reads in
+  ``prompt_tokens_details.cached_tokens``, included in ``prompt_tokens``.
+* OpenRouter: same as OpenAI plus cache *writes* in
+  ``prompt_tokens_details.cache_write_tokens``, also included in
+  ``prompt_tokens``.
+* litellm-normalized: same nesting, but names the write field
+  ``prompt_tokens_details.cache_creation_tokens`` (and additionally mirrors the
+  Anthropic top-level fields), with ``prompt_tokens`` as the grand total.
+* Anthropic native: ``cache_read_input_tokens`` / ``cache_creation_input_tokens``
+  top-level, additive to (not included in) ``input_tokens``.
+* DeepSeek: ``prompt_cache_hit_tokens`` / ``prompt_cache_miss_tokens``, with
+  ``prompt_tokens = hit + miss``.
+
+What decides whether cached tokens must be subtracted out of the input count is
+**which prompt field the vendor uses**, not which cache field appears:
+
+* ``prompt_tokens`` present -> cached + cache-write tokens are *included* in it
+  (OpenAI family, DeepSeek, OpenRouter, litellm); subtract both so
+  ``input_tokens`` holds only the regular-rate portion.
+* only ``input_tokens`` (Anthropic native) -> cached tokens are *additive*;
+  leave ``input_tokens`` untouched.
+
+``normalize_usage`` maps all of them onto one canonical ``NormalizedUsage``
+shape so billing code needs no vendor knowledge. The known dialects' field
+names do not collide, so a single union parser is safe; a vendor whose fields
+would genuinely conflict needs a dedicated branch here.
+"""
+
+from pydantic.v1 import BaseModel
+
+
+class NormalizedUsage(BaseModel):
+    """Canonical token usage: input_tokens never includes cached tokens."""
+
+    input_tokens: int = 0
+    output_tokens: int = 0
+    cache_read_tokens: int = 0
+    cache_write_tokens: int = 0
+
+
+def parse_token_count(value: object) -> int:
+    """Parse a token count from various formats (int, float, str, bool)."""
+    if isinstance(value, bool):
+        return 0
+    if isinstance(value, int):
+        return max(0, value)
+    if isinstance(value, float):
+        return max(0, int(value))
+    if isinstance(value, str):
+        try:
+            return max(0, int(float(value)))
+        except ValueError:
+            return 0
+    return 0
+
+
+def _first_token_count(usage_data: dict, *fields: str) -> int:
+    """Return the first positive token count among the given fields."""
+    for field in fields:
+        value = parse_token_count(usage_data.get(field, 0))
+        if value > 0:
+            return value
+    return 0
+
+
+def _extract_cache_tokens(usage_data: dict) -> tuple[int, int]:
+    """Pull (cache_read, cache_write) across all known dialects.
+
+    Precedence (highest first), independent for reads and writes:
+
+    * Anthropic top-level: ``cache_read_input_tokens`` /
+      ``cache_creation_input_tokens``.
+    * Nested ``prompt_tokens_details``: ``cached_tokens`` for reads;
+      ``cache_creation_tokens`` (litellm) or ``cache_write_tokens``
+      (OpenRouter) for writes.
+    * DeepSeek: ``prompt_cache_hit_tokens`` for reads (no write concept).
+    """
+    cache_read = parse_token_count(usage_data.get("cache_read_input_tokens", 0))
+    cache_write = parse_token_count(usage_data.get("cache_creation_input_tokens", 0))
+
+    prompt_details = usage_data.get("prompt_tokens_details")
+    if isinstance(prompt_details, dict):
+        if not cache_read:
+            cache_read = parse_token_count(prompt_details.get("cached_tokens", 0))
+        if not cache_write:
+            cache_write = _first_token_count(
+                prompt_details, "cache_creation_tokens", "cache_write_tokens"
+            )
+
+    if not cache_read:
+        # DeepSeek: prompt_tokens = prompt_cache_hit_tokens + prompt_cache_miss_tokens
+        cache_read = parse_token_count(usage_data.get("prompt_cache_hit_tokens", 0))
+
+    return cache_read, cache_write
+
+
+def normalize_usage(usage_data: object) -> NormalizedUsage | None:
+    """Map a vendor usage dict onto the canonical shape, or None if absent.
+
+    Cached reads and writes are subtracted from the input count exactly once,
+    only for dialects that report a ``prompt_tokens`` grand total that already
+    includes them (OpenAI family, DeepSeek, OpenRouter, litellm). Anthropic
+    native reports them additively under ``input_tokens`` and is left untouched.
+    """
+    if not isinstance(usage_data, dict):
+        return None
+
+    output_tokens = _first_token_count(
+        usage_data, "completion_tokens", "output_tokens"
+    )
+    cache_read, cache_write = _extract_cache_tokens(usage_data)
+
+    # ``prompt_tokens`` is the inclusive grand total; ``input_tokens`` (Anthropic
+    # native) excludes cached tokens. The field chosen decides whether to subtract.
+    if "prompt_tokens" in usage_data:
+        input_tokens = parse_token_count(usage_data.get("prompt_tokens", 0))
+        input_tokens = max(0, input_tokens - cache_read - cache_write)
+    else:
+        input_tokens = parse_token_count(usage_data.get("input_tokens", 0))
+
+    return NormalizedUsage(
+        input_tokens=input_tokens,
+        output_tokens=output_tokens,
+        cache_read_tokens=cache_read,
+        cache_write_tokens=cache_write,
+    )

routstr/proxy.py

@@ -1,3 +1,4 @@
+import asyncio
 import json
 from typing import Any
 
@@ -23,6 +24,7 @@ from .payment.helpers import (
     calculate_discounted_max_cost,
     check_token_balance,
     create_error_response,
+    create_upstream_error_response,
     get_max_cost_for_model,
 )
 from .payment.models import Model
@@ -210,9 +212,7 @@ async def proxy(
                     e,
                 )
                 if i == len(all_upstreams) - 1:
-                    last_error_response = create_error_response(
-                        "upstream_error", str(e), 502, request=request
-                    )
+                    last_error_response = create_upstream_error_response(e, request)
                 continue
         return last_error_response or create_error_response(
             "upstream_error", "All upstreams failed", 502, request=request
@@ -282,11 +282,10 @@ async def proxy(
                     last_error = e
                 continue
 
+        if last_error is not None:
+            return create_upstream_error_response(last_error, request)
         return create_error_response(
-            "upstream_error",
-            str(last_error) if last_error else "All upstreams failed",
-            502,
-            request=request,
+            "upstream_error", "All upstreams failed", 502, request=request
         )
 
     elif auth := headers.get("authorization", None):
@@ -342,9 +341,7 @@ async def proxy(
             except UpstreamError as e:
                 logger.warning(f"Upstream {upstream.provider_type} failed (GET): {e}")
                 if i == len(upstreams) - 1:
-                    last_error_response = create_error_response(
-                        "upstream_error", str(e), 502, request=request
-                    )
+                    last_error_response = create_upstream_error_response(e, request)
                 continue
         return last_error_response or create_error_response(
             "upstream_error", "All upstreams failed", 502, request=request
@@ -492,6 +489,21 @@ async def proxy(
 
             return response
 
+        except asyncio.CancelledError:
+            logger.warning(
+                "Client disconnected mid-request, reverting reservation",
+                extra={
+                    "path": path,
+                    "model": model_id,
+                    "key_hash": key.hashed_key[:8] + "...",
+                    "max_cost_for_model": max_cost_for_model,
+                },
+            )
+            await asyncio.shield(
+                revert_pay_for_request(key, session, max_cost_for_model)
+            )
+            raise
+
         except UpstreamError as e:
             logger.warning(
                 "Upstream %s failed for model=%s: %s",
@@ -509,9 +521,7 @@ async def proxy(
             # If this was the last provider
             if i == len(upstreams) - 1:
                 await revert_pay_for_request(key, session, max_cost_for_model)
-                return create_error_response(
-                    "upstream_error", str(e), 502, request=request
-                )
+                return create_upstream_error_response(e, request)
 
             # Otherwise loop continues to next provider
             continue

routstr/upstream/base.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import asyncio
 import json
+import math
 import traceback
 import uuid
 from collections.abc import AsyncGenerator, AsyncIterator, Iterator
@@ -23,6 +24,7 @@ from ..core.db import (
     store_cashu_transaction,
 )
 from ..core.exceptions import UpstreamError
+from ..core.redaction import redact_org_ids
 from ..payment.cost_calculation import (
     CostData,
     CostDataError,
@@ -35,13 +37,19 @@ from ..payment.models import (
     Pricing,
     _calculate_usd_max_costs,
     _update_model_sats_pricing,
+    backfill_cache_pricing,
     list_models,
 )
 from ..payment.price import sats_usd_price
 from ..wallet import recieve_token, send_token
 from . import messages_dispatch
+from .cache_breakpoints import (
+    inject_anthropic_cache_breakpoints,
+    is_explicit_cache_model,
+)
 from .count_tokens import count_tokens_locally
 from .litellm_routing import detect_litellm_prefix
+from .rate_limit import UPSTREAM_RATE_LIMIT, classify_rate_limit
 
 logger = get_logger(__name__)
 
@@ -432,6 +440,19 @@ class BaseUpstreamProvider:
 
         return body
 
+    def _upstream_accepts_cache_control(self) -> bool:
+        """True when this upstream accepts explicit ``cache_control`` markers.
+
+        Only OpenRouter (documents Anthropic + Alibaba explicit caching) and the
+        native Anthropic API accept the markers. Stamping them toward an
+        automatic-cache or non-supporting upstream risks a 400, so injection is
+        confined to these. Base URL is also checked so an OpenRouter endpoint
+        configured through the generic provider is still recognised.
+        """
+        if self.provider_type in ("openrouter", "anthropic"):
+            return True
+        return "openrouter.ai" in (self.base_url or "")
+
     def prepare_request_body(
         self, body: bytes | None, model_obj: Model
     ) -> bytes | None:
@@ -501,6 +522,27 @@ class BaseUpstreamProvider:
                 data["stream_options"] = merged
                 changed = True
 
+        # Explicit-cache models (Anthropic Claude, Alibaba Qwen / deepseek-v3.2)
+        # cache nothing without ``cache_control`` markers in the body. Clients
+        # that don't recognise a routstr URL as one of these never send them, so
+        # caching silently never engages over routstr even though it works
+        # against OpenRouter directly. Stamp the standard breakpoints so caching
+        # works by default, deferring to any client-set markers. Gated to
+        # upstreams that accept the markers (OpenRouter / Anthropic) so they
+        # never leak to an automatic-cache provider that would reject them.
+        if (
+            "messages" in data
+            and isinstance(data.get("messages"), list)
+            and self._upstream_accepts_cache_control()
+            and is_explicit_cache_model(
+                model_obj.id,
+                model_obj.forwarded_model_id,
+                model_obj.canonical_slug,
+            )
+        ):
+            if inject_anthropic_cache_breakpoints(data):
+                changed = True
+
         if changed:
             return json.dumps(data).encode()
         return body
@@ -543,7 +585,7 @@ class BaseUpstreamProvider:
             preview = body_bytes.decode("utf-8", errors="ignore").strip()
             if preview:
                 message = preview[:500]
-        return message, upstream_code
+        return redact_org_ids(message), upstream_code
 
     async def on_upstream_error_redirect(
         self, status_code: int, error_message: str
@@ -586,10 +628,23 @@ class BaseUpstreamProvider:
             body_bytes = b""
             body_read_error = f"{type(exc).__name__}: {exc}"
 
+        # ``message`` is already redacted by ``_extract_upstream_error_message``;
+        # the raw body preview is redacted here before it reaches logs or the
+        # forwarded envelope so provider account identifiers never leak.
         message, upstream_code = self._extract_upstream_error_message(body_bytes)
-        body_preview = body_bytes.decode("utf-8", errors="ignore").strip()[:500]
+        body_preview = redact_org_ids(
+            body_bytes.decode("utf-8", errors="ignore").strip()[:500]
+        )
         is_json_body = _is_json_content_type(content_type)
 
+        # Classify upstream rate-limit failures into a stable, structured error.
+        rate_limit = classify_rate_limit(status_code, message, headers)
+        error_code: str | int = upstream_code or status_code
+        error_details: dict[str, object] | None = None
+        if rate_limit is not None:
+            error_code = UPSTREAM_RATE_LIMIT
+            error_details = rate_limit.as_details()
+
         logger.warning(
             "Upstream %s returned %s for model=%s path=%s: %s",
             self.provider_type,
@@ -603,6 +658,7 @@ class BaseUpstreamProvider:
                 "model": model_id or "unknown",
                 "upstream_status": status_code,
                 "upstream_code": upstream_code,
+                "error_code": error_code,
                 "upstream_content_type": content_type,
                 "upstream_request_id": upstream_request_id,
                 "message_preview": message[:200],
@@ -637,13 +693,41 @@ class BaseUpstreamProvider:
         ):
             headers.pop(header_name, None)
 
+        # Propagate a usable retry hint to the caller when the upstream supplied
+        # one but did not echo a ``Retry-After`` header. RFC 7231 delta-seconds
+        # is an integer, so round sub-second hints up to a usable ``1``.
+        if (
+            rate_limit is not None
+            and rate_limit.retry_after_seconds is not None
+            and "retry-after" not in {k.lower() for k in headers}
+        ):
+            headers["Retry-After"] = str(max(1, math.ceil(rate_limit.retry_after_seconds)))
+
         if is_json_body:
             if not content_type:
                 headers.pop("content-type", None)
                 headers.pop("Content-Type", None)
             media_type = content_type or None
+            # Re-serialise the body with organization IDs stripped. The narrow
+            # ``org-*`` regex preserves the surrounding JSON structure.
+            redacted_text = redact_org_ids(body_bytes.decode("utf-8", errors="ignore"))
+            redacted_body = redacted_text.encode()
+            # Surface the stable rate-limit classification on the forwarded
+            # body so callers can switch on ``error.code`` without parsing the
+            # provider-specific message. Fall back to the redacted bytes if the
+            # body is not a JSON object with an ``error`` mapping.
+            if rate_limit is not None:
+                try:
+                    parsed = json.loads(redacted_text)
+                    err = parsed.get("error") if isinstance(parsed, dict) else None
+                    if isinstance(err, dict):
+                        err["code"] = UPSTREAM_RATE_LIMIT
+                        err["details"] = error_details
+                        redacted_body = json.dumps(parsed).encode()
+                except (ValueError, AttributeError):
+                    pass
             return Response(
-                content=body_bytes,
+                content=redacted_body,
                 status_code=status_code,
                 headers=headers,
                 media_type=media_type,
@@ -654,15 +738,18 @@ class BaseUpstreamProvider:
         for header_name in ("content-type", "Content-Type"):
             headers.pop(header_name, None)
 
+        error_obj: dict[str, object] = {
+            "message": message or "Upstream returned a non-JSON error response",
+            "type": "upstream_error",
+            "code": error_code,
+            "upstream_status": status_code,
+            "upstream_content_type": content_type or None,
+            "upstream_body_preview": body_preview or None,
+        }
+        if error_details is not None:
+            error_obj["details"] = error_details
         envelope = {
-            "error": {
-                "message": message or "Upstream returned a non-JSON error response",
-                "type": "upstream_error",
-                "code": upstream_code or status_code,
-                "upstream_status": status_code,
-                "upstream_content_type": content_type or None,
-                "upstream_body_preview": body_preview or None,
-            },
+            "error": error_obj,
             "request_id": getattr(request.state, "request_id", None),
         }
 
@@ -727,7 +814,9 @@ class BaseUpstreamProvider:
                     except Exception:
                         pass
 
-            def _process_event(raw_event: bytes) -> Iterator[bytes]:
+            def _process_event(
+                raw_event: bytes, final: bool = False
+            ) -> Iterator[bytes]:
                 """Process one complete SSE event block (lines up to a blank line).
 
                 Handles arbitrary upstream framing across every supported
@@ -833,6 +922,12 @@ class BaseUpstreamProvider:
                         return
                     yield prefix + b"data: " + json.dumps(obj).encode() + b"\n\n"
                 else:
+                    if final:
+                        # Final flush of a truncated tail: the upstream closed
+                        # mid-event, so ``data`` is incomplete JSON. Emitting it
+                        # as a ``data:`` frame would hand the client invalid
+                        # JSON (the "unexpected token" parse error). Drop it.
+                        return
                     # Non-JSON data payload (partial fragment already reassembled
                     # by buffering, or a provider control string). Re-prefix each
                     # line so multi-line ``data`` stays valid SSE framing - a bare
@@ -851,7 +946,13 @@ class BaseUpstreamProvider:
                 # boundary-independent for every provider.
                 buffer = b""
                 async for chunk in response.aiter_bytes():
-                    buffer += chunk.replace(b"\r\n", b"\n")
+                    # Normalize the *joined* buffer, not each chunk in
+                    # isolation: a CRLF event delimiter can straddle two
+                    # ``aiter_bytes`` chunks (``...\r`` then ``\n...``). A
+                    # per-chunk replace would leave a stray ``\r`` and the
+                    # ``\n\n`` split would miss the delimiter, merging two
+                    # events into one frame and breaking SSE clients.
+                    buffer = (buffer + chunk).replace(b"\r\n", b"\n")
                     while b"\n\n" in buffer:
                         raw_event, buffer = buffer.split(b"\n\n", 1)
                         for out in _process_event(raw_event):
@@ -859,7 +960,7 @@ class BaseUpstreamProvider:
 
                 # Flush any trailing event that lacked a final blank line.
                 if buffer.strip():
-                    for out in _process_event(buffer):
+                    for out in _process_event(buffer, final=True):
                         yield out
 
                 async with create_session() as session:
@@ -1018,7 +1119,10 @@ class BaseUpstreamProvider:
                 response_json["id"] = f"chatcmpl-{uuid.uuid4()}"
 
             cost_data = await adjust_payment_for_tokens(
-                key, response_json, session, deducted_max_cost
+                key,
+                response_json,
+                session,
+                deducted_max_cost,
             )
 
             await session.refresh(key)
@@ -1162,7 +1266,9 @@ class BaseUpstreamProvider:
                     except Exception:
                         pass
 
-            def _process_event(raw_event: bytes) -> Iterator[bytes]:
+            def _process_event(
+                raw_event: bytes, final: bool = False
+            ) -> Iterator[bytes]:
                 """Process one complete SSE event block for the Responses API.
 
                 Buffers full events (delimited by a blank line) so parsing is
@@ -1232,6 +1338,11 @@ class BaseUpstreamProvider:
 
                     yield prefix + b"data: " + json.dumps(obj).encode() + b"\n\n"
                 else:
+                    if final:
+                        # Final flush of a truncated tail: upstream closed
+                        # mid-event, so ``data`` is incomplete JSON. Dropping it
+                        # avoids handing the client an invalid ``data:`` frame.
+                        return
                     # Re-prefix each line so multi-line ``data`` stays valid SSE
                     # framing for the client.
                     body = b"".join(
@@ -1244,14 +1355,20 @@ class BaseUpstreamProvider:
                 # delimiter so parsing is independent of byte boundaries.
                 buffer = b""
                 async for chunk in response.aiter_bytes():
-                    buffer += chunk.replace(b"\r\n", b"\n")
+                    # Normalize the *joined* buffer, not each chunk in
+                    # isolation: a CRLF event delimiter can straddle two
+                    # ``aiter_bytes`` chunks (``...\r`` then ``\n...``). A
+                    # per-chunk replace would leave a stray ``\r`` and the
+                    # ``\n\n`` split would miss the delimiter, merging two
+                    # events into one frame and breaking SSE clients.
+                    buffer = (buffer + chunk).replace(b"\r\n", b"\n")
                     while b"\n\n" in buffer:
                         raw_event, buffer = buffer.split(b"\n\n", 1)
                         for out in _process_event(raw_event):
                             yield out
 
                 if buffer.strip():
-                    for out in _process_event(buffer):
+                    for out in _process_event(buffer, final=True):
                         yield out
 
                 # Always emit a cost-bearing data chunk
@@ -1436,7 +1553,10 @@ class BaseUpstreamProvider:
                 response_json["id"] = f"chatcmpl-{uuid.uuid4()}"
 
             cost_data = await adjust_payment_for_tokens(
-                key, response_json, session, deducted_max_cost
+                key,
+                response_json,
+                session,
+                deducted_max_cost,
             )
 
             await session.refresh(key)
@@ -1631,7 +1751,10 @@ class BaseUpstreamProvider:
                             "usage": None,
                         }
                         cost_data = await adjust_payment_for_tokens(
-                            fresh_key, fallback, new_session, max_cost_for_model
+                            fresh_key,
+                            fallback,
+                            new_session,
+                            max_cost_for_model,
                         )
                         usage_finalized = True
                         return f"event: cost\ndata: {json.dumps({'cost': cost_data})}\n\n".encode()
@@ -1850,7 +1973,10 @@ class BaseUpstreamProvider:
                 response_json["usage"] = {"input_tokens": input_tokens}
 
             cost_data = await adjust_payment_for_tokens(
-                key, response_json, session, deducted_max_cost
+                key,
+                response_json,
+                session,
+                deducted_max_cost,
             )
 
             self.inject_cost_metadata(response_json, cost_data, key)
@@ -1952,7 +2078,10 @@ class BaseUpstreamProvider:
             response_json["model"] = requested_model
 
         cost_data = await adjust_payment_for_tokens(
-            key, response_json, session, max_cost_for_model
+            key,
+            response_json,
+            session,
+            max_cost_for_model,
         )
         self.inject_cost_metadata(response_json, cost_data, key)
 
@@ -2440,9 +2569,16 @@ class BaseUpstreamProvider:
                         body_bytes = await response.aread()
                     except Exception:
                         body_bytes = b""
-                    body_preview = body_bytes.decode(
-                        "utf-8", errors="ignore"
-                    ).strip()[:500]
+                    # Redact provider account identifiers before the body text
+                    # reaches logs or the raised error.
+                    body_preview = redact_org_ids(
+                        body_bytes.decode("utf-8", errors="ignore").strip()[:500]
+                    )
+                    rate_limit = classify_rate_limit(
+                        response.status_code,
+                        body_preview,
+                        dict(response.headers),
+                    )
                     logger.error(
                         "Upstream %s returned %s for model=%s path=%s: %s",
                         self.provider_type,
@@ -2454,6 +2590,7 @@ class BaseUpstreamProvider:
                             "provider": self.provider_type,
                             "model": original_model_id or "unknown",
                             "status_code": response.status_code,
+                            "error_code": rate_limit.code if rate_limit else None,
                             "reason_phrase": response.reason_phrase,
                             "path": path,
                             "body_preview": body_preview,
@@ -2466,6 +2603,8 @@ class BaseUpstreamProvider:
                         f"for model {original_model_id or 'unknown'}: "
                         f"{body_preview[:200] or '<empty>'}",
                         status_code=response.status_code,
+                        code=rate_limit.code if rate_limit else None,
+                        details=rate_limit.as_details() if rate_limit else None,
                     )
 
                 try:
@@ -2762,9 +2901,16 @@ class BaseUpstreamProvider:
                         body_bytes = await response.aread()
                     except Exception:
                         body_bytes = b""
-                    body_preview = body_bytes.decode(
-                        "utf-8", errors="ignore"
-                    ).strip()[:500]
+                    # Redact provider account identifiers before the body text
+                    # reaches logs or the raised error.
+                    body_preview = redact_org_ids(
+                        body_bytes.decode("utf-8", errors="ignore").strip()[:500]
+                    )
+                    rate_limit = classify_rate_limit(
+                        response.status_code,
+                        body_preview,
+                        dict(response.headers),
+                    )
                     logger.error(
                         "Upstream %s returned %s for model=%s path=%s: %s",
                         self.provider_type,
@@ -2776,6 +2922,7 @@ class BaseUpstreamProvider:
                             "provider": self.provider_type,
                             "model": original_model_id or "unknown",
                             "status_code": response.status_code,
+                            "error_code": rate_limit.code if rate_limit else None,
                             "path": path,
                             "body_preview": body_preview,
                         },
@@ -2787,6 +2934,8 @@ class BaseUpstreamProvider:
                         f"for model {original_model_id or 'unknown'}: "
                         f"{body_preview[:200] or '<empty>'}",
                         status_code=response.status_code,
+                        code=rate_limit.code if rate_limit else None,
+                        details=rate_limit.as_details() if rate_limit else None,
                     )
 
                 try:
@@ -3025,44 +3174,46 @@ class BaseUpstreamProvider:
             extra={"model": model, "has_usage": "usage" in response_data},
         )
 
-        async with create_session() as session:
-            match await calculate_cost(response_data, max_cost_for_model, session):
-                case MaxCostData() as cost:
-                    logger.debug(
-                        "Using max cost pricing",
-                        extra={"model": model, "max_cost_msats": cost.total_msats},
-                    )
-                    return cost
-                case CostData() as cost:
-                    logger.debug(
-                        "Using token-based pricing",
-                        extra={
-                            "model": model,
-                            "total_cost_msats": cost.total_msats,
-                            "input_msats": cost.input_msats,
-                            "output_msats": cost.output_msats,
-                        },
-                    )
-                    return cost
-                case CostDataError() as error:
-                    logger.error(
-                        "Cost calculation error",
-                        extra={
-                            "model": model,
-                            "error_message": error.message,
-                            "error_code": error.code,
-                        },
-                    )
-                    raise HTTPException(
-                        status_code=400,
-                        detail={
-                            "error": {
-                                "message": error.message,
-                                "type": "invalid_request_error",
-                                "code": error.code,
-                            }
-                        },
-                    )
+        match await calculate_cost(
+            response_data,
+            max_cost_for_model,
+        ):
+            case MaxCostData() as cost:
+                logger.debug(
+                    "Using max cost pricing",
+                    extra={"model": model, "max_cost_msats": cost.total_msats},
+                )
+                return cost
+            case CostData() as cost:
+                logger.debug(
+                    "Using token-based pricing",
+                    extra={
+                        "model": model,
+                        "total_cost_msats": cost.total_msats,
+                        "input_msats": cost.input_msats,
+                        "output_msats": cost.output_msats,
+                    },
+                )
+                return cost
+            case CostDataError() as error:
+                logger.error(
+                    "Cost calculation error",
+                    extra={
+                        "model": model,
+                        "error_message": error.message,
+                        "error_code": error.code,
+                    },
+                )
+                raise HTTPException(
+                    status_code=400,
+                    detail={
+                        "error": {
+                            "message": error.message,
+                            "type": "invalid_request_error",
+                            "code": error.code,
+                        }
+                    },
+                )
         return None
 
     async def send_refund(
@@ -4562,14 +4713,19 @@ class BaseUpstreamProvider:
     def _apply_provider_fee_to_model(self, model: Model) -> Model:
         """Apply provider fee to model's USD pricing and calculate max costs.
 
+        Cache rates missing from the upstream pricing feed are backfilled from
+        litellm's cost map first, so they carry the provider fee like every
+        other price component.
+
         Args:
             model: Model object to update
 
         Returns:
             Model with provider fee applied to pricing and max costs calculated
         """
+        base_pricing = backfill_cache_pricing(model.id, model.pricing)
         adjusted_pricing = Pricing.parse_obj(
-            {k: v * self.provider_fee for k, v in model.pricing.dict().items()}
+            {k: v * self.provider_fee for k, v in base_pricing.dict().items()}
         )
 
         temp_model = Model(

routstr/upstream/cache_breakpoints.py

@@ -0,0 +1,157 @@
+"""Inject explicit prompt-cache breakpoints into OpenAI-shaped requests.
+
+Some upstreams cache *explicitly*: the request must carry
+``cache_control: {"type": "ephemeral"}`` markers on the content blocks that
+should be cached. Two model families use this identical wire format:
+
+* **Anthropic Claude** — direct or via OpenRouter's ``anthropic/*`` models.
+* **Alibaba's explicit-cache models on OpenRouter** — ``qwen/qwen3-max``,
+  ``qwen/qwen-plus``, ``qwen/qwen3.6-plus``, ``qwen/qwen3-coder-plus``,
+  ``qwen/qwen3-coder-flash`` and ``deepseek/deepseek-v3.2`` — which OpenRouter
+  documents as using "the same syntax as Anthropic explicit caching".
+
+Every other provider routstr proxies (OpenAI, Azure, xAI/Grok, Groq, Moonshot,
+default DeepSeek, Gemini implicit, Fireworks) caches *automatically* and needs
+no markers — they are left untouched.
+
+A client that doesn't know it is talking to one of these models *through*
+routstr (e.g. an OpenAI-compatible coding agent pointed at a routstr URL) never
+emits the markers — it only adds them when it recognises the provider as
+OpenRouter. So caching silently never engages over routstr even though the same
+client caches fine talking to OpenRouter directly.
+
+This module restores caching by stamping the standard breakpoints onto the
+forwarded body — the system prompt, the last tool, and the last conversation
+message (the format allows up to four; we use three, matching the common
+agent convention) — but only when the client supplied none of its own, so
+explicit client control always wins. The caller is responsible for only
+applying this toward an upstream that accepts the markers (OpenRouter /
+Anthropic), so they never leak to a provider that would reject them.
+"""
+
+from __future__ import annotations
+
+from typing import Any
+
+# The single ephemeral marker stamped onto each chosen breakpoint. A 5-minute
+# TTL (the default for ``ephemeral``) — deliberately not the 1h tier, which
+# carries a higher cache-write premium and should stay opt-in.
+EPHEMERAL_CACHE_CONTROL: dict[str, str] = {"type": "ephemeral"}
+
+# Alibaba's explicit-cache models on OpenRouter. Matched as substrings of the
+# model id (any spelling routstr carries). Snapshot endpoints that OpenRouter
+# documents as *not* supporting explicit caching (e.g. ``qwen3.5-plus-02-15``)
+# are different families and deliberately absent from this list.
+_ALIBABA_EXPLICIT_CACHE_SLUGS: tuple[str, ...] = (
+    "qwen3-max",
+    "qwen-plus",
+    "qwen3.6-plus",
+    "qwen3-coder-plus",
+    "qwen3-coder-flash",
+    "deepseek-v3.2",
+)
+
+
+def is_explicit_cache_model(model_id: str | None, *fallbacks: str | None) -> bool:
+    """True when the target model uses the explicit ``cache_control`` dialect.
+
+    Covers the Claude family (broadly — every Claude model supports it) and
+    Alibaba's documented explicit-cache models, across the id spellings routstr
+    carries: the OpenRouter id (``anthropic/claude-...``, ``qwen/qwen3-max``),
+    the bare upstream id, and any forwarded/canonical alias.
+    """
+    for candidate in (model_id, *fallbacks):
+        if not candidate:
+            continue
+        lowered = candidate.lower()
+        if "claude" in lowered or "anthropic/" in lowered:
+            return True
+        if any(slug in lowered for slug in _ALIBABA_EXPLICIT_CACHE_SLUGS):
+            return True
+    return False
+
+
+def _has_cache_control(obj: Any) -> bool:
+    """Recursively detect any client-supplied ``cache_control`` marker."""
+    if isinstance(obj, dict):
+        if "cache_control" in obj:
+            return True
+        return any(_has_cache_control(v) for v in obj.values())
+    if isinstance(obj, list):
+        return any(_has_cache_control(v) for v in obj)
+    return False
+
+
+def body_has_cache_control(data: dict) -> bool:
+    """True when the request already carries cache_control on messages/tools."""
+    return _has_cache_control(data.get("messages")) or _has_cache_control(
+        data.get("tools")
+    )
+
+
+def _stamp_text_content(message: dict) -> bool:
+    """Add the ephemeral marker to a message's last text block.
+
+    A string content is promoted to the array form Anthropic requires for
+    cache markers; an existing array gets the marker on its last text part.
+    Returns True when a marker was placed.
+    """
+    content = message.get("content")
+    if isinstance(content, str):
+        if not content:
+            return False
+        message["content"] = [
+            {
+                "type": "text",
+                "text": content,
+                "cache_control": dict(EPHEMERAL_CACHE_CONTROL),
+            }
+        ]
+        return True
+    if isinstance(content, list):
+        for part in reversed(content):
+            if isinstance(part, dict) and part.get("type") == "text":
+                part["cache_control"] = dict(EPHEMERAL_CACHE_CONTROL)
+                return True
+    return False
+
+
+def _stamp_system_prompt(messages: list) -> None:
+    for message in messages:
+        if isinstance(message, dict) and message.get("role") in (
+            "system",
+            "developer",
+        ):
+            _stamp_text_content(message)
+            return
+
+
+def _stamp_last_tool(tools: Any) -> None:
+    if isinstance(tools, list) and tools and isinstance(tools[-1], dict):
+        tools[-1]["cache_control"] = dict(EPHEMERAL_CACHE_CONTROL)
+
+
+def _stamp_last_conversation_message(messages: list) -> None:
+    for message in reversed(messages):
+        if isinstance(message, dict) and message.get("role") in ("user", "assistant"):
+            if _stamp_text_content(message):
+                return
+
+
+def inject_anthropic_cache_breakpoints(data: dict) -> bool:
+    """Stamp ephemeral cache breakpoints onto an OpenAI-shaped chat body.
+
+    Mutates ``data`` in place (the established convention in
+    ``prepare_request_body``) and returns True when anything changed. No-ops
+    when the body isn't chat-shaped or the client already set cache_control.
+    """
+    messages = data.get("messages")
+    if not isinstance(messages, list) or not messages:
+        return False
+    if body_has_cache_control(data):
+        return False
+
+    _stamp_system_prompt(messages)
+    _stamp_last_tool(data.get("tools"))
+    _stamp_last_conversation_message(messages)
+    return True

routstr/upstream/deepseek_v4_pricing_shim.py

@@ -0,0 +1,66 @@
+"""TEMPORARY: local DeepSeek V4 pricing shim.
+
+litellm's bundled cost map does not yet ship ``deepseek-v4-flash`` /
+``deepseek-v4-pro``. Without an entry, ``backfill_cache_pricing`` cannot find a
+``cache_read_input_token_cost`` and cache reads fall back to the full input
+rate — a ~60% overcharge on cache hits (DeepSeek hits are ~0.2x input).
+
+This module injects the missing entries into ``litellm.model_cost`` at startup
+so the existing backfill path resolves them. Rates mirror the open upstream PR
+https://github.com/BerriAI/litellm/pull/26380 (issue
+https://github.com/BerriAI/litellm/issues/30430).
+
+=== REMOVAL (once litellm ships these models) ===
+Delete this file and the single ``register_deepseek_v4_pricing()`` call in
+``routstr/core/main.py``. Nothing else depends on it. Entries are only added
+when absent, so a stale shim is harmless after upstream lands — but remove it.
+"""
+
+import litellm
+
+from ..core import get_logger
+
+logger = get_logger(__name__)
+
+# USD per token. Source: BerriAI/litellm PR #26380.
+_DEEPSEEK_V4_RATES: dict[str, dict[str, float]] = {
+    "deepseek-v4-flash": {
+        "input_cost_per_token": 1.4e-07,
+        "output_cost_per_token": 2.8e-07,
+        "cache_read_input_token_cost": 2.8e-08,
+        "cache_creation_input_token_cost": 0.0,
+        "input_cost_per_token_cache_hit": 2.8e-08,
+    },
+    "deepseek-v4-pro": {
+        "input_cost_per_token": 1.74e-06,
+        "output_cost_per_token": 3.48e-06,
+        "cache_read_input_token_cost": 1.4e-07,
+        "cache_creation_input_token_cost": 0.0,
+        "input_cost_per_token_cache_hit": 1.4e-07,
+    },
+}
+
+
+def register_deepseek_v4_pricing() -> None:
+    """Inject DeepSeek V4 pricing into ``litellm.model_cost`` if absent.
+
+    Idempotent and non-destructive: a key already present in the cost map
+    (e.g. once litellm ships it) is left untouched. Registers both the bare
+    (``deepseek-v4-flash``) and prefixed (``deepseek/deepseek-v4-flash``)
+    spellings since ``backfill_cache_pricing`` tries both.
+    """
+    added = []
+    for bare, rates in _DEEPSEEK_V4_RATES.items():
+        for key in (bare, f"deepseek/{bare}"):
+            if key in litellm.model_cost:
+                continue
+            entry: dict[str, object] = dict(rates)
+            entry["litellm_provider"] = "deepseek"
+            entry["mode"] = "chat"
+            litellm.model_cost[key] = entry
+            added.append(key)
+    if added:
+        logger.info(
+            "Registered temporary DeepSeek V4 pricing shim",
+            extra={"models": added},
+        )

routstr/upstream/messages_dispatch.py

@@ -29,7 +29,9 @@ import litellm
 
 from ..core import get_logger
 from ..core.exceptions import UpstreamError
+from ..core.redaction import redact_org_ids
 from ..payment.models import Model
+from .rate_limit import classify_rate_limit
 
 logger = get_logger(__name__)
 
@@ -505,23 +507,33 @@ async def dispatch_anthropic_messages(
     try:
         result = await litellm.anthropic.messages.acreate(**kwargs)
     except Exception as exc:
-        exc_message = getattr(exc, "message", None) or str(exc) or repr(exc)
+        raw_message = getattr(exc, "message", None) or str(exc) or repr(exc)
+        # Redact provider account identifiers before the message reaches logs
+        # or the surfaced error.
+        exc_message = redact_org_ids(raw_message)
         exc_status = getattr(exc, "status_code", None)
         exc_response = getattr(exc, "response", None)
         response_text = None
         if exc_response is not None:
             try:
-                response_text = getattr(exc_response, "text", str(exc_response))
+                response_text = redact_org_ids(
+                    getattr(exc_response, "text", str(exc_response))
+                )
             except Exception:
                 response_text = "<unreadable>"
+        status_for_classify = exc_status if isinstance(exc_status, int) else 502
+        rate_limit = classify_rate_limit(
+            status_for_classify, exc_message, getattr(exc, "headers", None)
+        )
         logger.error(
             "litellm dispatch failed",
             extra={
                 "error": exc_message,
                 "error_type": type(exc).__name__,
                 "status_code": exc_status,
+                "error_code": rate_limit.code if rate_limit else None,
                 "llm_provider": getattr(exc, "llm_provider", None),
-                "body": getattr(exc, "body", None),
+                "body": redact_org_ids(str(getattr(exc, "body", "") or "")) or None,
                 "response_text": response_text,
                 "model": litellm_model,
                 "api_base": base_url,
@@ -529,7 +541,9 @@ async def dispatch_anthropic_messages(
         )
         raise UpstreamError(
             f"Upstream error via litellm: {exc_message}",
-            status_code=exc_status if isinstance(exc_status, int) else 502,
+            status_code=status_for_classify,
+            code=rate_limit.code if rate_limit else None,
+            details=rate_limit.as_details() if rate_limit else None,
         ) from exc
 
     if not client_stream and hasattr(result, "__aiter__"):

routstr/upstream/openrouter.py

@@ -1,3 +1,4 @@
+import json
 from typing import TYPE_CHECKING
 
 import httpx
@@ -18,6 +19,38 @@ class OpenRouterUpstreamProvider(BaseUpstreamProvider):
     supports_anthropic_messages = True
     litellm_provider_prefix = "openrouter/"
 
+    def prepare_request_body(
+        self, body: bytes | None, model_obj: Model
+    ) -> bytes | None:
+        """Set provider.require_parameters on tool-use requests.
+
+        Without it OpenRouter can route a tool call to an endpoint that doesn't
+        support function calling and 404 with "No endpoints found that support
+        tool use". We leave a client-supplied value untouched.
+        """
+        body = super().prepare_request_body(body, model_obj)
+        if not body:
+            return body
+
+        try:
+            data = json.loads(body)
+        except json.JSONDecodeError:
+            return body
+
+        if not isinstance(data, dict) or not data.get("tools"):
+            return body
+
+        provider = data.get("provider")
+        if not isinstance(provider, dict):
+            provider = {}
+
+        if "require_parameters" in provider:
+            return body
+
+        provider["require_parameters"] = True
+        data["provider"] = provider
+        return json.dumps(data).encode()
+
     def _apply_provider_field(self, response_json: object) -> None:
         """Stamp the ``provider`` field for OpenRouter responses.
 

routstr/upstream/rate_limit.py

@@ -0,0 +1,136 @@
+"""Detection and parsing of upstream provider rate-limit errors.
+
+Upstream OpenAI-compatible providers signal rate limits via HTTP 429 and/or a
+human-readable message such as::
+
+    Rate limit reached for gpt-5.5-2026-04-23 (for limit gpt-5.5) in organization
+    org-XXXX on tokens per min (TPM): Limit 180000000, Used 180000000,
+    Requested 8929. Please try again in 2ms.
+
+This module classifies those failures into a stable :data:`UPSTREAM_RATE_LIMIT`
+code and extracts useful debugging fields. All retained text is redacted of
+organization IDs first.
+"""
+
+from __future__ import annotations
+
+import re
+from dataclasses import asdict, dataclass
+
+from ..core.redaction import redact_org_ids
+
+# Stable error code callers can switch on to distinguish upstream rate limits
+# from generic request failures. The literal value matches the identifier named
+# in issue #555 ("UPSTREAM_RATE_LIMIT") so the public API contract is exact.
+UPSTREAM_RATE_LIMIT = "UPSTREAM_RATE_LIMIT"
+
+# Message fragments that indicate a rate-limit even when the status code is not
+# 429 (some providers wrap it in a 400/500 envelope).
+_RATE_LIMIT_MARKERS = (
+    "rate limit reached",
+    "rate_limit_exceeded",
+    "rate limit exceeded",
+    "too many requests",
+)
+
+_MODEL_RE = re.compile(r"Rate limit reached for ([^\s(]+)", re.IGNORECASE)
+_LIMIT_NAME_RE = re.compile(r"\(for limit ([^)]+)\)", re.IGNORECASE)
+_METRIC_RE = re.compile(r"on ([a-z ]+\((?:TPM|RPM|TPD|RPD|IPM)\))", re.IGNORECASE)
+_LIMIT_RE = re.compile(r"Limit (\d+)", re.IGNORECASE)
+_USED_RE = re.compile(r"Used (\d+)", re.IGNORECASE)
+_REQUESTED_RE = re.compile(r"Requested (\d+)", re.IGNORECASE)
+_RETRY_RE = re.compile(r"try again in ([\d.]+)\s*(ms|s)", re.IGNORECASE)
+
+
+@dataclass
+class RateLimitInfo:
+    """Structured, redaction-safe view of an upstream rate-limit error."""
+
+    code: str
+    message: str
+    model: str | None = None
+    limit_name: str | None = None
+    metric: str | None = None
+    limit: int | None = None
+    used: int | None = None
+    requested: int | None = None
+    retry_after_seconds: float | None = None
+
+    def as_details(self) -> dict[str, object]:
+        """Return a JSON-serialisable dict for embedding in an error envelope."""
+        return {k: v for k, v in asdict(self).items() if v is not None}
+
+
+def _looks_like_rate_limit(status_code: int, message: str) -> bool:
+    if status_code == 429:
+        return True
+    lowered = message.lower()
+    return any(marker in lowered for marker in _RATE_LIMIT_MARKERS)
+
+
+def _parse_retry_after_header(headers: dict[str, str] | None) -> float | None:
+    """Parse a ``Retry-After`` header (delta-seconds form) into seconds."""
+    if not headers:
+        return None
+    raw = headers.get("retry-after") or headers.get("Retry-After")
+    if raw is None:
+        return None
+    try:
+        return float(str(raw).strip())
+    except (TypeError, ValueError):
+        return None
+
+
+def _int_or_none(match: re.Match[str] | None) -> int | None:
+    if match is None:
+        return None
+    try:
+        return int(match.group(1))
+    except (TypeError, ValueError):
+        return None
+
+
+def classify_rate_limit(
+    status_code: int,
+    message: str,
+    headers: dict[str, str] | None = None,
+) -> RateLimitInfo | None:
+    """Classify an upstream error as a rate-limit and extract its fields.
+
+    Args:
+        status_code: HTTP status code from the upstream response.
+        message: Upstream error message (may contain sensitive identifiers).
+        headers: Optional upstream response headers, used for ``Retry-After``.
+
+    Returns:
+        A :class:`RateLimitInfo` when the error is a rate-limit, else ``None``.
+    """
+    message = message or ""
+    if not _looks_like_rate_limit(status_code, message):
+        return None
+
+    redacted = redact_org_ids(message)
+
+    model_match = _MODEL_RE.search(redacted)
+    metric_match = _METRIC_RE.search(redacted)
+
+    retry_after = _parse_retry_after_header(headers)
+    if retry_after is None:
+        retry_match = _RETRY_RE.search(redacted)
+        if retry_match is not None:
+            value = float(retry_match.group(1))
+            retry_after = value / 1000.0 if retry_match.group(2).lower() == "ms" else value
+
+    limit_name_match = _LIMIT_NAME_RE.search(redacted)
+
+    return RateLimitInfo(
+        code=UPSTREAM_RATE_LIMIT,
+        message=redacted,
+        model=model_match.group(1) if model_match else None,
+        limit_name=limit_name_match.group(1).strip() if limit_name_match else None,
+        metric=metric_match.group(1).strip() if metric_match else None,
+        limit=_int_or_none(_LIMIT_RE.search(redacted)),
+        used=_int_or_none(_USED_RE.search(redacted)),
+        requested=_int_or_none(_REQUESTED_RE.search(redacted)),
+        retry_after_seconds=retry_after,
+    )

routstr/wallet.py

@@ -1,4 +1,5 @@
 import asyncio
+import re
 import time
 import typing
 from typing import TypedDict
@@ -35,6 +36,24 @@ async def get_balance(unit: str) -> int:
     return wallet.available_balance.amount
 
 
+async def _redeem_same_mint(
+    wallet: Wallet, token_obj: Token
+) -> tuple[int, str, str]:  # amount, unit, mint_url
+    """Redeem proofs at their own issuing mint (no cross-mint swap).
+
+    split() re-mints the incoming proofs into fresh ones we own so the sender
+    can't double-spend them. With include_fees=True the mint deducts its NUT-02
+    per-proof input fee, so we end up holding only `amount - input_fees`. Credit
+    that, not the face value, or routstr over-credits the user and its wallet
+    drifts insolvent.
+    """
+    await wallet.load_mint(keyset_id=token_obj.keysets[0])
+    wallet.verify_proofs_dleq(token_obj.proofs)
+    input_fees = wallet.get_fees_for_proofs(token_obj.proofs)
+    await wallet.split(proofs=token_obj.proofs, amount=0, include_fees=True)
+    return int(token_obj.amount) - input_fees, token_obj.unit, token_obj.mint
+
+
 async def recieve_token(
     token: str,
 ) -> tuple[int, str, str]:  # amount, unit, mint_url
@@ -48,12 +67,7 @@ async def recieve_token(
     if token_obj.mint not in settings.cashu_mints:
         return await swap_to_primary_mint(token_obj, wallet)
 
-    await wallet.load_mint(keyset_id=token_obj.keysets[0])
-
-    wallet.verify_proofs_dleq(token_obj.proofs)
-    await wallet.split(proofs=token_obj.proofs, amount=0, include_fees=True)
-
-    return token_obj.amount, token_obj.unit, token_obj.mint
+    return await _redeem_same_mint(wallet, token_obj)
 
 
 async def send(amount: int, unit: str, mint_url: str | None = None) -> tuple[int, str]:
@@ -116,6 +130,72 @@ async def send_token(amount: int, unit: str, mint_url: str | None = None) -> str
     return token
 
 
+# A foreign mint's fee_reserve is a non-binding estimate (NUT-05): the mint may
+# demand more when re-quoting or at melt execution. Instead of padding the
+# estimate with a safety buffer (which strands the margin at the foreign mint
+# on every swap), the swap retries with the amount recomputed from the fees the
+# mint actually demands, up to this many attempts.
+_MAX_SWAP_ATTEMPTS = 3
+
+_MINT_ERROR_CODE_RE = re.compile(r"\(Code: (\d+)\)")
+_MELT_SHORTFALL_RE = re.compile(r"Provided: (\d+), needed: (\d+)")
+
+# Insufficient-melt-inputs failures differ across mint implementations. 11005 is
+# the registered "Transaction is not balanced" code (cdk), specific enough to
+# trust on the code alone. 11000 is nutshell's generic, unregistered
+# TransactionError covering many unrelated failures, so it only counts as a fee
+# shortfall alongside the "not enough inputs" detail text. With no code suffix at
+# all, that same text is the only signal.
+
+
+def _net_minted_amount(amount_msat: int, token_unit: str, fees: int) -> int:
+    """
+    Convert the token value minus fees (given in the token unit) into an
+    amount in the primary mint's unit.
+    """
+    fee_msat = fees * 1000 if token_unit == "sat" else fees
+    remaining_msat = amount_msat - fee_msat
+    if settings.primary_mint_unit == "sat":
+        return int(remaining_msat // 1000)
+    return int(remaining_msat)
+
+
+def _melt_insufficient_shortfall(error: Exception) -> int | None:
+    """
+    Classify a melt failure: return the observed shortfall (in the token unit)
+    when the mint rejected the inputs as insufficient, or None when the failure
+    is unrelated to fees and must not be retried (e.g. a Lightning payment
+    failure, where a smaller invoice would not help).
+
+    Cashu errors carry no structured amounts (NUT-00 defines only detail/code,
+    flattened to "Mint Error: <detail> (Code: <code>)" by cashu-py), so the
+    classification uses the code and the shortfall must be inferred: the
+    "Provided: X, needed: Y" amounts are nutshell-specific free text and only
+    refine the shortfall when present; otherwise shrink one unit at a time.
+    """
+    message = str(error)
+    code_match = _MINT_ERROR_CODE_RE.search(message)
+    code = code_match.group(1) if code_match is not None else None
+    has_shortfall_text = "not enough inputs" in message.lower()
+
+    match code:
+        case "11005":  # registered TransactionUnbalanced: trust the code
+            pass
+        case "11000" if has_shortfall_text:  # generic nutshell error: needs the text
+            pass
+        case None if has_shortfall_text:  # no code suffix: text is the only signal
+            pass
+        case _:  # other codes, a bare 11000, or no signal: must not retry
+            return None
+
+    amounts = _MELT_SHORTFALL_RE.search(message)
+    if amounts is not None:
+        provided, needed = int(amounts.group(1)), int(amounts.group(2))
+        if needed > provided:
+            return needed - provided
+    return 1
+
+
 async def _calculate_swap_amount(
     amount_msat: int,
     token_unit: str,
@@ -154,26 +234,18 @@ async def _calculate_swap_amount(
 
         fee_reserve = dummy_melt_quote.fee_reserve
         input_fees = token_wallet.get_fees_for_proofs(proofs)
-        if token_unit == "sat":
-            fee_msat = (fee_reserve + input_fees) * 1000
-        else:
-            fee_msat = fee_reserve + input_fees
-
-        amount_msat_after_fee = amount_msat - fee_msat
-
-        if settings.primary_mint_unit == "sat":
-            minted_amount = int(amount_msat_after_fee // 1000)
-        else:
-            minted_amount = int(amount_msat_after_fee)
+        total_fees = fee_reserve + input_fees
+        minted_amount = _net_minted_amount(amount_msat, token_unit, total_fees)
 
         if minted_amount <= 0:
-            raise ValueError(f"Fees ({fee_reserve + input_fees} {token_unit}) exceed token amount")
+            raise ValueError(f"Fees ({total_fees} {token_unit}) exceed token amount")
 
         logger.info(
             "swap_to_primary_mint: fee estimation result",
             extra={
                 "token_amount_sat": amount_msat // 1000,
-                "estimated_fee_sat": fee_msat // 1000,
+                "estimated_fee": total_fees,
+                "estimated_fee_unit": token_unit,
                 "input_fees": input_fees,
                 "minted_amount": minted_amount,
                 "minted_unit": settings.primary_mint_unit,
@@ -213,10 +285,9 @@ async def swap_to_primary_mint(
         amount_msat = token_amount
     else:
         raise ValueError("Invalid unit")
-    primary_wallet = await get_wallet(settings.primary_mint, settings.primary_mint_unit)
-
-    # If the token is already from the primary mint, we don't need to swap
-    # and we definitely don't want to calculate or pay fees.
+    # If the token is already from the primary mint, we don't need a cross-mint
+    # swap — redeem it same-mint. There's no melt/Lightning fee, but the mint's
+    # NUT-02 input fee still applies; _redeem_same_mint accounts for it.
     if token_obj.mint == settings.primary_mint:
         logger.info(
             "swap_to_primary_mint: token already on primary mint, skipping swap",
@@ -226,8 +297,9 @@ async def swap_to_primary_mint(
                 "unit": token_obj.unit,
             },
         )
-        await token_wallet.split(proofs=token_obj.proofs, amount=0, include_fees=True)
-        return token_amount, token_obj.unit, token_obj.mint
+        return await _redeem_same_mint(token_wallet, token_obj)
+
+    primary_wallet = await get_wallet(settings.primary_mint, settings.primary_mint_unit)
 
     minted_amount = await _calculate_swap_amount(
         amount_msat,
@@ -238,67 +310,116 @@ async def swap_to_primary_mint(
         token_obj.proofs,
     )
 
-    mint_quote = await primary_wallet.request_mint(minted_amount)
-    logger.info(
-        "swap_to_primary_mint: mint quote received",
-        extra={"mint_quote_id": mint_quote.quote},
-    )
+    # The estimate above is non-binding: the mint may demand a higher fee on the
+    # real quote or reject the melt outright. Retry the quote/melt cycle with the
+    # amount recomputed from the fees the mint actually demands.
+    observed_extra_fee = 0
+    attempt = 0
+    while True:
+        attempt += 1
+        mint_quote = await primary_wallet.request_mint(minted_amount)
+        logger.info(
+            "swap_to_primary_mint: mint quote received",
+            extra={"mint_quote_id": mint_quote.quote, "attempt": attempt},
+        )
 
-    melt_quote = await token_wallet.melt_quote(mint_quote.request)
-    input_fees = token_wallet.get_fees_for_proofs(token_obj.proofs)
-    total_needed = melt_quote.amount + melt_quote.fee_reserve + input_fees
-    logger.info(
-        "swap_to_primary_mint: melt quote received",
-        extra={
-            "melt_quote_id": melt_quote.quote,
-            "melt_amount": melt_quote.amount,
-            "melt_fee_reserve": melt_quote.fee_reserve,
-            "input_fees": input_fees,
-            "total_needed": total_needed,
-            "token_amount": token_amount,
-        },
-    )
-
-    if total_needed > token_amount:
-        logger.warning(
-            "swap_to_primary_mint: insufficient token amount for melt fees",
+        melt_quote = await token_wallet.melt_quote(mint_quote.request)
+        input_fees = token_wallet.get_fees_for_proofs(token_obj.proofs)
+        total_needed = melt_quote.amount + melt_quote.fee_reserve + input_fees
+        logger.info(
+            "swap_to_primary_mint: melt quote received",
             extra={
-                "token_amount": token_amount,
+                "melt_quote_id": melt_quote.quote,
                 "melt_amount": melt_quote.amount,
                 "melt_fee_reserve": melt_quote.fee_reserve,
                 "input_fees": input_fees,
                 "total_needed": total_needed,
-                "shortfall": total_needed - token_amount,
+                "token_amount": token_amount,
+                "attempt": attempt,
             },
         )
-        raise ValueError(
-            f"Token amount ({token_amount} {token_obj.unit}) is insufficient to cover "
-            f"melt fees. Needed: {total_needed} {token_obj.unit} "
-            f"(amount: {melt_quote.amount} + fee: {melt_quote.fee_reserve} + input_fees: {input_fees})"
-        )
 
-    try:
-        _ = await token_wallet.melt(
-            proofs=token_obj.proofs,
-            invoice=mint_quote.request,
-            fee_reserve_sat=melt_quote.fee_reserve,
-            quote_id=melt_quote.quote,
-        )
-    except Exception as e:
-        logger.error(
-            "swap_to_primary_mint: melt failed",
-            extra={
-                "error": str(e),
-                "error_type": type(e).__name__,
-                "foreign_mint": token_obj.mint,
-                "token_amount": token_amount,
-                "melt_quote_id": melt_quote.quote,
-                "total_needed": total_needed,
-            },
-        )
-        raise ValueError(
-            f"Failed to melt token from foreign mint {token_obj.mint}: {e}"
-        ) from e
+        if total_needed > token_amount:
+            recomputed = _net_minted_amount(
+                amount_msat,
+                token_obj.unit,
+                melt_quote.fee_reserve + input_fees + observed_extra_fee,
+            )
+            if attempt >= _MAX_SWAP_ATTEMPTS or recomputed <= 0:
+                logger.warning(
+                    "swap_to_primary_mint: insufficient token amount for melt fees",
+                    extra={
+                        "token_amount": token_amount,
+                        "melt_amount": melt_quote.amount,
+                        "melt_fee_reserve": melt_quote.fee_reserve,
+                        "input_fees": input_fees,
+                        "total_needed": total_needed,
+                        "shortfall": total_needed - token_amount,
+                        "attempts": attempt,
+                    },
+                )
+                raise ValueError(
+                    f"Token amount ({token_amount} {token_obj.unit}) is insufficient to cover "
+                    f"melt fees. Needed: {total_needed} {token_obj.unit} "
+                    f"(amount: {melt_quote.amount} + fee: {melt_quote.fee_reserve} + input_fees: {input_fees})"
+                )
+            logger.warning(
+                "swap_to_primary_mint: melt quote exceeds token amount, retrying",
+                extra={
+                    "total_needed": total_needed,
+                    "token_amount": token_amount,
+                    "retry_minted_amount": recomputed,
+                    "attempt": attempt,
+                },
+            )
+            minted_amount = recomputed
+            continue
+
+        try:
+            _ = await token_wallet.melt(
+                proofs=token_obj.proofs,
+                invoice=mint_quote.request,
+                fee_reserve_sat=melt_quote.fee_reserve,
+                quote_id=melt_quote.quote,
+            )
+        except Exception as e:
+            shortfall = _melt_insufficient_shortfall(e)
+            recomputed = 0
+            if shortfall is not None:
+                observed_extra_fee += shortfall
+                recomputed = _net_minted_amount(
+                    amount_msat,
+                    token_obj.unit,
+                    melt_quote.fee_reserve + input_fees + observed_extra_fee,
+                )
+            if shortfall is None or attempt >= _MAX_SWAP_ATTEMPTS or recomputed <= 0:
+                logger.error(
+                    "swap_to_primary_mint: melt failed",
+                    extra={
+                        "error": str(e),
+                        "error_type": type(e).__name__,
+                        "foreign_mint": token_obj.mint,
+                        "token_amount": token_amount,
+                        "melt_quote_id": melt_quote.quote,
+                        "total_needed": total_needed,
+                        "attempts": attempt,
+                    },
+                )
+                raise ValueError(
+                    f"Failed to melt token from foreign mint {token_obj.mint}: {e}"
+                ) from e
+            logger.warning(
+                "swap_to_primary_mint: mint demanded more than quoted at melt, retrying",
+                extra={
+                    "shortfall": shortfall,
+                    "retry_minted_amount": recomputed,
+                    "attempt": attempt,
+                },
+            )
+            minted_amount = recomputed
+            continue
+
+        break
 
     logger.info(
         "swap_to_primary_mint: melt succeeded, minting on primary",
@@ -428,7 +549,11 @@ async def credit_balance(
             .where(col(db.ApiKey.hashed_key) == key.hashed_key)
             .values(balance=(db.ApiKey.balance) + amount)
         )
-        await session.exec(stmt)  # type: ignore[call-overload]
+        result = await session.exec(stmt)  # type: ignore[call-overload]
+        # If pruning removed this key after redemption, do not commit a no-op
+        # balance update and pretend the top-up succeeded.
+        if (getattr(result, "rowcount", 0) or 0) == 0:
+            raise ValueError("API key disappeared before credit could be recorded")
         await session.commit()
         await session.refresh(key)
 
@@ -567,11 +692,19 @@ async def fetch_all_balances(
             }
             return error_result
 
+    # Build the set of mints to inspect. Received tokens are stored against
+    # ``primary_mint`` (which defaults to a real mint even when ``cashu_mints``
+    # is empty), so include it as a fallback — otherwise a node that accepts
+    # payments would still report empty balances when ``cashu_mints`` is unset.
+    mint_urls: list[str] = list(settings.cashu_mints)
+    if settings.primary_mint and settings.primary_mint not in mint_urls:
+        mint_urls.append(settings.primary_mint)
+
     # Create tasks for all mint/unit combinations
     async with db.create_session() as session:
         tasks = [
             fetch_balance(session, mint_url, unit)
-            for mint_url in settings.cashu_mints
+            for mint_url in mint_urls
             for unit in units
         ]
 

tests/integration/test_child_keys_api.py

@@ -69,9 +69,14 @@ async def test_wallet_info_child_key_no_child_keys(
     info_response = await integration_client.get("/v1/wallet/info")
     assert info_response.status_code == 200
     info_data = info_response.json()
+    parent_key = authenticated_client._test_api_key  # type: ignore[attr-defined]
+    parent_key_hash = parent_key.removeprefix("sk-")
 
     assert info_data["is_child"] is True
     assert "child_keys" not in info_data
+    assert "parent_key" not in info_data
+    assert info_data["parent_key_preview"] == parent_key_hash[:8] + "..."
+    assert info_data["parent_key_preview"] not in {parent_key, parent_key_hash}
 
 
 @pytest.mark.integration

tests/integration/test_free_response_stale_reservation.py

@@ -0,0 +1,146 @@
+"""Regression tests for charging after stale reservation cleanup."""
+
+import time
+import uuid
+from unittest.mock import patch
+
+import pytest
+from sqlmodel.ext.asyncio.session import AsyncSession
+
+from routstr.core.db import ApiKey
+from routstr.payment.cost_calculation import CostData
+
+
+def _make_key(balance: int, reserved: int) -> ApiKey:
+    return ApiKey(
+        hashed_key=f"test_{uuid.uuid4().hex}",
+        balance=balance,
+        reserved_balance=reserved,
+        total_spent=0,
+        total_requests=1,
+    )
+
+
+def _cost_data(total_msats: int) -> CostData:
+    return CostData(
+        base_msats=0,
+        input_msats=total_msats // 2,
+        output_msats=total_msats - total_msats // 2,
+        total_msats=total_msats,
+        total_usd=0.0,
+        input_tokens=100,
+        output_tokens=100,
+    )
+
+
+@pytest.mark.asyncio
+async def test_overrun_charges_after_reservation_swept(
+    integration_session: AsyncSession,
+) -> None:
+    """Overrun finalize must charge even when the reservation was already released."""
+    from routstr.auth import adjust_payment_for_tokens
+
+    deducted_max_cost = 990  # discounted reservation
+    actual_token_cost = 1000  # actual cost overruns the reservation
+
+    # Sweeper has zeroed reserved_balance but left balance untouched.
+    key = _make_key(balance=1000, reserved=0)
+    integration_session.add(key)
+    await integration_session.commit()
+
+    response_data = {
+        "model": "test-model",
+        "usage": {"prompt_tokens": 100, "completion_tokens": 100},
+    }
+
+    with patch(
+        "routstr.auth.calculate_cost",
+        return_value=_cost_data(actual_token_cost),
+    ):
+        await adjust_payment_for_tokens(
+            key, response_data, integration_session, deducted_max_cost
+        )
+
+    await integration_session.refresh(key)
+
+    assert key.total_spent == actual_token_cost, (
+        f"Request was not billed (total_spent={key.total_spent}) — free response bug"
+    )
+    assert key.balance == 1000 - actual_token_cost, (
+        f"Balance not charged: {key.balance}"
+    )
+    assert key.balance >= 0
+    assert key.reserved_balance == 0
+
+
+@pytest.mark.asyncio
+async def test_free_response_path_closed_end_to_end(
+    integration_session: AsyncSession,
+    patched_db_engine: None,
+) -> None:
+    """A reservation released by the real sweeper must not yield a free response."""
+    from routstr.auth import adjust_payment_for_tokens, pay_for_request
+    from routstr.core.db import create_session, release_stale_reservations
+
+    deducted_max_cost = 990
+    actual_token_cost = 1000
+    key_hash = f"test_sweep_{uuid.uuid4().hex}"
+
+    async with create_session() as session:
+        session.add(
+            ApiKey(
+                hashed_key=key_hash,
+                balance=1000,
+                reserved_balance=0,
+                total_spent=0,
+                total_requests=0,
+            )
+        )
+        await session.commit()
+
+    # Reserve the request, then backdate reserved_at so the sweeper treats it as
+    # stale (simulates a stream that outlived stale_reservation_timeout_seconds).
+    async with create_session() as session:
+        key = await session.get(ApiKey, key_hash)
+        assert key is not None
+        await pay_for_request(key, deducted_max_cost, session)
+        await session.refresh(key)
+        assert key.reserved_balance == deducted_max_cost
+        key.reserved_at = int(time.time()) - 10_000
+        session.add(key)
+        await session.commit()
+
+    # Sweeper releases the stale reservation without charging.
+    async with create_session() as session:
+        released = await release_stale_reservations(session, max_age_seconds=300)
+        assert released == 1
+
+    async with create_session() as session:
+        key = await session.get(ApiKey, key_hash)
+        assert key is not None
+        assert key.reserved_balance == 0, "Precondition: sweeper zeroed the reservation"
+
+        response_data = {
+            "model": "test-model",
+            "usage": {"prompt_tokens": 100, "completion_tokens": 100},
+        }
+        with patch(
+            "routstr.auth.calculate_cost",
+            return_value=_cost_data(actual_token_cost),
+        ):
+            await adjust_payment_for_tokens(
+                key, response_data, session, deducted_max_cost
+            )
+
+    async with create_session() as session:
+        final = await session.get(ApiKey, key_hash)
+        assert final is not None
+
+    assert final.total_spent == actual_token_cost, (
+        f"Free response: total_spent={final.total_spent}, expected {actual_token_cost}"
+    )
+    assert final.balance == 1000 - actual_token_cost, (
+        f"Balance not charged after sweep: {final.balance}"
+    )
+    assert final.balance >= 0
+    assert final.reserved_balance == 0

tests/integration/test_key_logic.py

@@ -1,12 +1,14 @@
+import asyncio
 import time
 from datetime import datetime, timedelta
 
 import pytest
+from fastapi import HTTPException
 from sqlmodel import select
 from sqlmodel.ext.asyncio.session import AsyncSession
 
 from routstr.auth import pay_for_request
-from routstr.core.db import ApiKey
+from routstr.core.db import ApiKey, create_session
 
 
 @pytest.mark.asyncio
@@ -120,6 +122,270 @@ async def test_periodic_key_reset_job(integration_session: AsyncSession) -> None
     assert key2.total_spent == 0
 
 
+@pytest.mark.asyncio
+async def test_balance_limit_enforced_atomically_under_concurrency(
+    patched_db_engine: None,
+) -> None:
+    parent_hash = "parent_limit_atomic"
+    child_hash = "child_limit_atomic"
+    cost = 300
+
+    async with create_session() as session:
+        parent = ApiKey(hashed_key=parent_hash, balance=10000)
+        child = ApiKey(
+            hashed_key=child_hash,
+            balance=0,
+            parent_key_hash=parent_hash,
+            balance_limit=cost,
+            total_spent=0,
+        )
+        session.add(parent)
+        session.add(child)
+        await session.commit()
+
+    results: list[str] = []
+
+    async def attempt() -> None:
+        async with create_session() as session:
+            fresh_child = await session.get(ApiKey, child_hash)
+            assert fresh_child is not None
+            try:
+                await pay_for_request(fresh_child, cost, session)
+                results.append("success")
+            except HTTPException as exc:
+                assert exc.status_code == 402
+                results.append("blocked")
+
+    await asyncio.gather(attempt(), attempt())
+
+    assert sorted(results) == ["blocked", "success"], (
+        f"Expected exactly one success and one 402, got: {results}"
+    )
+
+    async with create_session() as session:
+        final_child = await session.get(ApiKey, child_hash)
+        assert final_child is not None
+
+    assert final_child.reserved_balance == cost, (
+        f"Child reserved_balance should equal one reservation, "
+        f"got {final_child.reserved_balance}"
+    )
+
+
+@pytest.mark.asyncio
+async def test_parallel_payments_with_parent_and_child_key(
+    patched_db_engine: None,
+) -> None:
+    parent_hash = "parent_parallel_mixed"
+    child_hash = "child_parallel_mixed"
+    cost = 300
+
+    async with create_session() as session:
+        parent = ApiKey(hashed_key=parent_hash, balance=10000)
+        child = ApiKey(
+            hashed_key=child_hash,
+            balance=0,
+            parent_key_hash=parent_hash,
+            balance_limit=2 * cost,
+        )
+        session.add(parent)
+        session.add(child)
+        await session.commit()
+
+    async def attempt(key_hash: str) -> str:
+        async with create_session() as session:
+            fresh_key = await session.get(ApiKey, key_hash)
+            assert fresh_key is not None
+            try:
+                await pay_for_request(fresh_key, cost, session)
+                return "success"
+            except HTTPException as exc:
+                assert exc.status_code == 402
+                return "blocked"
+
+    results = await asyncio.gather(attempt(parent_hash), attempt(child_hash))
+
+    assert results == ["success", "success"], (
+        f"Both parent and child payments should succeed, got: {results}"
+    )
+
+    async with create_session() as session:
+        final_parent = await session.get(ApiKey, parent_hash)
+        final_child = await session.get(ApiKey, child_hash)
+        assert final_parent is not None
+        assert final_child is not None
+
+    # Both requests bill the parent; only the child request reserves on the child.
+    assert final_parent.reserved_balance == 2 * cost
+    assert final_parent.total_requests == 2
+    assert final_child.reserved_balance == cost
+    assert final_child.total_requests == 1
+
+
+@pytest.mark.asyncio
+async def test_balance_limit_with_existing_total_spent_under_concurrency(
+    patched_db_engine: None,
+) -> None:
+    parent_hash = "parent_total_spent"
+    child_hash = "child_total_spent"
+    cost = 300
+
+    async with create_session() as session:
+        parent = ApiKey(hashed_key=parent_hash, balance=10000)
+        # 700 already spent against a 1000 limit: only one more 300 request fits.
+        child = ApiKey(
+            hashed_key=child_hash,
+            balance=0,
+            parent_key_hash=parent_hash,
+            balance_limit=1000,
+            total_spent=700,
+        )
+        session.add(parent)
+        session.add(child)
+        await session.commit()
+
+    results: list[str] = []
+
+    async def attempt() -> None:
+        async with create_session() as session:
+            fresh_child = await session.get(ApiKey, child_hash)
+            assert fresh_child is not None
+            try:
+                await pay_for_request(fresh_child, cost, session)
+                results.append("success")
+            except HTTPException as exc:
+                assert exc.status_code == 402
+                results.append("blocked")
+
+    await asyncio.gather(attempt(), attempt())
+
+    assert sorted(results) == ["blocked", "success"], (
+        f"Expected exactly one success and one 402, got: {results}"
+    )
+
+    async with create_session() as session:
+        final_child = await session.get(ApiKey, child_hash)
+        assert final_child is not None
+
+    assert final_child.reserved_balance == cost
+    assert final_child.total_spent == 700
+
+
+@pytest.mark.asyncio
+async def test_balance_limit_with_existing_reserved_balance(
+    patched_db_engine: None,
+) -> None:
+    parent_hash = "parent_reserved_set"
+    blocked_hash = "child_reserved_blocked"
+    allowed_hash = "child_reserved_allowed"
+    cost = 300
+
+    async with create_session() as session:
+        parent = ApiKey(hashed_key=parent_hash, balance=10000)
+        # 800 already reserved against a 1000 limit: another 300 must be rejected.
+        blocked_child = ApiKey(
+            hashed_key=blocked_hash,
+            balance=0,
+            parent_key_hash=parent_hash,
+            balance_limit=1000,
+            reserved_balance=800,
+        )
+        # 500 reserved against a 1000 limit: another 300 still fits.
+        allowed_child = ApiKey(
+            hashed_key=allowed_hash,
+            balance=0,
+            parent_key_hash=parent_hash,
+            balance_limit=1000,
+            reserved_balance=500,
+        )
+        session.add(parent)
+        session.add(blocked_child)
+        session.add(allowed_child)
+        await session.commit()
+
+    async with create_session() as session:
+        fresh_blocked = await session.get(ApiKey, blocked_hash)
+        assert fresh_blocked is not None
+        with pytest.raises(HTTPException) as exc_info:
+            await pay_for_request(fresh_blocked, cost, session)
+        assert exc_info.value.status_code == 402
+
+    async with create_session() as session:
+        fresh_allowed = await session.get(ApiKey, allowed_hash)
+        assert fresh_allowed is not None
+        await pay_for_request(fresh_allowed, cost, session)
+
+    async with create_session() as session:
+        final_blocked = await session.get(ApiKey, blocked_hash)
+        final_allowed = await session.get(ApiKey, allowed_hash)
+        final_parent = await session.get(ApiKey, parent_hash)
+        assert final_blocked is not None
+        assert final_allowed is not None
+        assert final_parent is not None
+
+    assert final_blocked.reserved_balance == 800, "Rejected request must not reserve"
+    assert final_blocked.total_requests == 0
+    assert final_allowed.reserved_balance == 500 + cost
+    assert final_allowed.total_requests == 1
+    # Only the allowed request should have billed the parent.
+    assert final_parent.reserved_balance == cost
+    assert final_parent.total_requests == 1
+
+
+@pytest.mark.asyncio
+async def test_child_reservation_discarded_when_parent_balance_depleted(
+    patched_db_engine: None,
+) -> None:
+    parent_hash = "parent_depleted"
+    child_hash = "child_depleted"
+    cost = 300
+
+    async with create_session() as session:
+        # Parent can only afford one request; child has no balance_limit.
+        parent = ApiKey(hashed_key=parent_hash, balance=cost)
+        child = ApiKey(
+            hashed_key=child_hash,
+            balance=0,
+            parent_key_hash=parent_hash,
+        )
+        session.add(parent)
+        session.add(child)
+        await session.commit()
+
+    results: list[str] = []
+
+    async def attempt() -> None:
+        async with create_session() as session:
+            fresh_child = await session.get(ApiKey, child_hash)
+            assert fresh_child is not None
+            try:
+                await pay_for_request(fresh_child, cost, session)
+                results.append("success")
+            except HTTPException as exc:
+                assert exc.status_code == 402
+                results.append("blocked")
+
+    await asyncio.gather(attempt(), attempt())
+
+    assert sorted(results) == ["blocked", "success"], (
+        f"Expected exactly one success and one 402, got: {results}"
+    )
+
+    async with create_session() as session:
+        final_parent = await session.get(ApiKey, parent_hash)
+        final_child = await session.get(ApiKey, child_hash)
+        assert final_parent is not None
+        assert final_child is not None
+
+    assert final_parent.reserved_balance == cost
+    # The failed request must not leave a committed reservation on the child.
+    assert final_child.reserved_balance == cost, (
+        f"Child reserved_balance should reflect only the successful request, "
+        f"got {final_child.reserved_balance}"
+    )
+    assert final_child.total_requests == 1
+
+
 @pytest.mark.asyncio
 async def test_refund_does_not_delete_key(integration_session: AsyncSession) -> None:
     # This requires mocking the router call or testing the logic in balance.py

tests/integration/test_prune_dead_api_keys.py

@@ -0,0 +1,283 @@
+"""
+Tests for prune_dead_api_keys — the janitor that removes provably-dead 0/0/0
+API keys (funded keys fully refunded/expired without ever being used, plus bare
+orphans), while protecting keys that are still meaningful.
+"""
+
+import time
+import uuid
+from collections.abc import Awaitable, Callable
+from typing import Any, cast
+
+import pytest
+from sqlalchemy.sql.dml import Update
+from sqlmodel import col, update
+
+from routstr.core.db import (
+    ApiKey,
+    CashuTransaction,
+    LightningInvoice,
+    create_session,
+    prune_dead_api_keys,
+)
+
+OLD = 100  # min_age_seconds used by the tests
+NOW = int(time.time())
+LONG_AGO = NOW - 10_000  # well past the grace period
+
+
+async def _exists(key_hash: str) -> bool:
+    async with create_session() as session:
+        return (await session.get(ApiKey, key_hash)) is not None
+
+
+def _dead_key(created_at: int | None) -> ApiKey:
+    return ApiKey(
+        hashed_key=f"dead_{uuid.uuid4().hex}",
+        balance=0,
+        reserved_balance=0,
+        total_spent=0,
+        total_requests=0,
+        created_at=created_at,
+    )
+
+
+@pytest.mark.asyncio
+async def test_prunes_old_refunded_zero_key(patched_db_engine: None) -> None:
+    """A funded-then-refunded key (0/0/0, NULL parent, old) is pruned."""
+    key = _dead_key(LONG_AGO)
+    async with create_session() as session:
+        session.add(key)
+        await session.commit()
+
+    async with create_session() as session:
+        pruned = await prune_dead_api_keys(session, OLD)
+
+    assert pruned == 1
+    assert not await _exists(key.hashed_key)
+
+
+@pytest.mark.asyncio
+async def test_grace_period_protects_fresh_key(patched_db_engine: None) -> None:
+    """A dead-looking but recently created key is protected by the grace period."""
+    key = _dead_key(int(time.time()))
+    async with create_session() as session:
+        session.add(key)
+        await session.commit()
+
+    async with create_session() as session:
+        pruned = await prune_dead_api_keys(session, OLD)
+
+    assert pruned == 0
+    assert await _exists(key.hashed_key)
+
+
+@pytest.mark.asyncio
+async def test_used_key_never_pruned(patched_db_engine: None) -> None:
+    """Keys with any spend/requests or live balance are never pruned."""
+    spent = _dead_key(LONG_AGO)
+    spent.total_spent = 1
+    requested = _dead_key(LONG_AGO)
+    requested.total_requests = 1
+    funded = _dead_key(LONG_AGO)
+    funded.balance = 1000
+    reserved = _dead_key(LONG_AGO)
+    reserved.reserved_balance = 500
+
+    async with create_session() as session:
+        for k in (spent, requested, funded, reserved):
+            session.add(k)
+        await session.commit()
+
+    async with create_session() as session:
+        pruned = await prune_dead_api_keys(session, OLD)
+
+    assert pruned == 0
+    for k in (spent, requested, funded, reserved):
+        assert await _exists(k.hashed_key)
+
+
+@pytest.mark.asyncio
+async def test_parent_and_child_keys_are_not_pruned(
+    patched_db_engine: None,
+) -> None:
+    """Pruning must not orphan child keys or delete valid children."""
+    parent = _dead_key(LONG_AGO)
+    child = ApiKey(
+        hashed_key=f"child_{uuid.uuid4().hex}",
+        balance=0,
+        reserved_balance=0,
+        total_spent=0,
+        total_requests=0,
+        created_at=LONG_AGO,
+        parent_key_hash=parent.hashed_key,
+    )
+    async with create_session() as session:
+        session.add(parent)
+        session.add(child)
+        await session.commit()
+
+    async with create_session() as session:
+        pruned = await prune_dead_api_keys(session, OLD)
+
+    assert pruned == 0
+    assert await _exists(parent.hashed_key)
+    assert await _exists(child.hashed_key)
+
+
+@pytest.mark.asyncio
+async def test_pending_invoice_protects_key(patched_db_engine: None) -> None:
+    """A key referenced by a pending topup invoice is never pruned mid-topup."""
+    key = _dead_key(LONG_AGO)
+    invoice = LightningInvoice(
+        id=f"inv_{uuid.uuid4().hex}",
+        bolt11=f"lnbc_{uuid.uuid4().hex}",
+        amount_sats=10,
+        description="topup",
+        payment_hash=uuid.uuid4().hex,
+        status="pending",
+        api_key_hash=key.hashed_key,
+        purpose="topup",
+        expires_at=NOW + 10_000,
+    )
+    async with create_session() as session:
+        session.add(key)
+        session.add(invoice)
+        await session.commit()
+
+    async with create_session() as session:
+        pruned = await prune_dead_api_keys(session, OLD)
+
+    assert pruned == 0
+    assert await _exists(key.hashed_key)
+
+
+@pytest.mark.asyncio
+async def test_paid_invoice_does_not_protect_key(patched_db_engine: None) -> None:
+    """A settled (non-pending) invoice does not keep a dead key alive."""
+    key = _dead_key(LONG_AGO)
+    invoice = LightningInvoice(
+        id=f"inv_{uuid.uuid4().hex}",
+        bolt11=f"lnbc_{uuid.uuid4().hex}",
+        amount_sats=10,
+        description="topup",
+        payment_hash=uuid.uuid4().hex,
+        status="paid",
+        api_key_hash=key.hashed_key,
+        purpose="topup",
+        expires_at=NOW - 1,
+    )
+    async with create_session() as session:
+        session.add(key)
+        session.add(invoice)
+        await session.commit()
+
+    async with create_session() as session:
+        pruned = await prune_dead_api_keys(session, OLD)
+
+    assert pruned == 1
+    assert not await _exists(key.hashed_key)
+
+
+@pytest.mark.asyncio
+async def test_key_that_becomes_meaningful_during_prune_survives(
+    patched_db_engine: None, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """Revalidate before unlink/delete so a late top-up cannot be pruned."""
+    key = _dead_key(LONG_AGO)
+    txn = CashuTransaction(
+        id=uuid.uuid4().hex,
+        token="cashuABC",
+        amount=21,
+        unit="sat",
+        type="in",
+        source="apikey",
+        api_key_hashed_key=key.hashed_key,
+    )
+    async with create_session() as session:
+        session.add(key)
+        session.add(txn)
+        await session.commit()
+
+    async with create_session() as session:
+        original_exec = cast(Callable[..., Awaitable[Any]], session.exec)
+        topped_up = False
+
+        async def exec_with_late_topup(
+            statement: Any, *args: Any, **kwargs: Any
+        ) -> Any:
+            nonlocal topped_up
+            if (
+                not topped_up
+                and isinstance(statement, Update)
+                and getattr(statement.table, "name", None) == "cashu_transactions"
+            ):
+                topped_up = True
+                async with create_session() as topup_session:
+                    await topup_session.exec(  # type: ignore[call-overload]
+                        update(ApiKey)
+                        .where(col(ApiKey.hashed_key) == key.hashed_key)
+                        .values(balance=42)
+                    )
+                    await topup_session.commit()
+            return await original_exec(statement, *args, **kwargs)
+
+        monkeypatch.setattr(session, "exec", exec_with_late_topup)
+        pruned = await prune_dead_api_keys(session, OLD)
+
+    assert pruned == 0
+    assert await _exists(key.hashed_key)
+    async with create_session() as session:
+        surviving = await session.get(CashuTransaction, txn.id)
+        assert surviving is not None
+        assert surviving.api_key_hashed_key == key.hashed_key
+
+
+@pytest.mark.asyncio
+async def test_transaction_audit_trail_preserved(patched_db_engine: None) -> None:
+    """Pruning a refunded key keeps its cashu_transactions, unlinked from the key."""
+    key = _dead_key(LONG_AGO)
+    txn = CashuTransaction(
+        id=uuid.uuid4().hex,
+        token="cashuABC",
+        amount=21,
+        unit="sat",
+        type="in",
+        source="apikey",
+        api_key_hashed_key=key.hashed_key,
+    )
+    async with create_session() as session:
+        session.add(key)
+        session.add(txn)
+        await session.commit()
+
+    async with create_session() as session:
+        pruned = await prune_dead_api_keys(session, OLD)
+
+    assert pruned == 1
+    assert not await _exists(key.hashed_key)
+
+    async with create_session() as session:
+        surviving = await session.get(CashuTransaction, txn.id)
+        assert surviving is not None, "Financial audit row must survive key deletion"
+        assert surviving.api_key_hashed_key is None, "Link must be nulled, not dangling"
+        assert surviving.amount == 21
+
+
+@pytest.mark.asyncio
+async def test_periodic_prune_disabled_returns_immediately(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Non-positive intervals disable the janitor."""
+    from unittest.mock import AsyncMock
+
+    from routstr import auth
+    from routstr.core.settings import settings
+
+    monkeypatch.setattr(settings, "dead_key_prune_interval_seconds", 0)
+    sleep_mock = AsyncMock()
+    monkeypatch.setattr(auth.asyncio, "sleep", sleep_mock)
+
+    await auth.periodic_dead_key_prune()
+
+    sleep_mock.assert_not_called()

tests/integration/test_swap_fee_retry.py

@@ -0,0 +1,194 @@
+"""
+Integration tests for reactive swap fee retries via the wallet topup endpoint.
+
+Foreign-mint tokens are swapped to the primary mint using the foreign mint's
+melt quote, whose fee_reserve is a non-binding estimate (NUT-05): the mint may
+demand more when re-quoting or at melt execution. These tests cover the
+endpoint behaviour in those cases:
+
+1. The mint demands one sat more at melt time than every quote reported
+   (the mint.cubabitcoin.org incident): the swap retries with a smaller
+   invoice and the topup succeeds, crediting the recomputed amount.
+2. The real melt quote reports a higher fee_reserve than the estimate: the
+   swap re-quotes from the observed fee and the topup succeeds.
+3. The mint escalates its fee demands on every attempt: the retry budget is
+   exhausted and the endpoint returns 400 with a clear error (never 500),
+   without ever executing a melt.
+"""
+
+from collections.abc import Callable
+from unittest.mock import AsyncMock, Mock, patch
+
+import pytest
+from httpx import AsyncClient, Response
+
+from routstr.core.settings import settings
+
+# Captured at collection time, before the integration_app fixture replaces it
+# with the testmint stub that bypasses swapping (see conftest.py).
+from routstr.wallet import recieve_token as _real_recieve_token
+
+PRIMARY_MINT = "http://primary:3338"
+
+
+def _make_swap_mocks(
+    token_amount: int,
+    fee_reserves: list[int],
+    input_fees: int = 0,
+    mint_url: str = "http://foreign-mint:3338",
+) -> tuple[Mock, Mock, Mock]:
+    """Return (token, token_wallet, primary_wallet) mocks that act like a mint.
+
+    Mint quotes pass the requested amount through their ``request`` field and
+    melt quotes echo that amount back, so the mocks stay consistent for
+    whatever amounts the implementation requests. ``fee_reserves`` supplies the
+    fee_reserve of each successive melt quote (the first serves the estimation
+    pass); requesting more quotes than provided fails the test.
+    """
+    mock_token = Mock()
+    mock_token.mint = mint_url
+    mock_token.unit = "sat"
+    mock_token.amount = token_amount
+    mock_token.keysets = ["keyset1"]
+    mock_token.proofs = [Mock(amount=token_amount)]
+
+    mock_token_wallet = Mock()
+    mock_token_wallet.load_mint = AsyncMock()
+    mock_token_wallet.load_proofs = AsyncMock()
+    mock_token_wallet.get_fees_for_proofs = Mock(return_value=input_fees)
+
+    mock_primary_wallet = Mock()
+    mock_primary_wallet.load_mint = AsyncMock()
+    mock_primary_wallet.load_proofs = AsyncMock()
+    mock_primary_wallet.available_balance = Mock(amount=0)
+    mock_primary_wallet.mint = AsyncMock(return_value=Mock())
+
+    fees = iter(fee_reserves)
+
+    def _next_fee() -> int:
+        try:
+            return next(fees)
+        except StopIteration:
+            raise AssertionError(
+                "more melt quotes requested than fee_reserves provided"
+            ) from None
+
+    mock_primary_wallet.request_mint = AsyncMock(
+        side_effect=lambda amount: Mock(quote=f"mint_quote_{amount}", request=amount)
+    )
+    mock_token_wallet.melt_quote = AsyncMock(
+        side_effect=lambda invoice: Mock(
+            quote=f"melt_quote_{invoice}", amount=invoice, fee_reserve=_next_fee()
+        )
+    )
+    mock_token_wallet.melt = AsyncMock(return_value=Mock())
+
+    return mock_token, mock_token_wallet, mock_primary_wallet
+
+
+def _wallet_router(primary_wallet: Mock, token_wallet: Mock) -> Callable[..., Mock]:
+    """Route get_wallet calls to the primary or foreign wallet mock by URL."""
+
+    def fake_get_wallet(mint_url: str, unit: str = "sat", load: bool = True) -> Mock:
+        return primary_wallet if mint_url == PRIMARY_MINT else token_wallet
+
+    return fake_get_wallet
+
+
+async def _post_topup(
+    client: AsyncClient,
+    mock_token: Mock,
+    token_wallet: Mock,
+    primary_wallet: Mock,
+) -> Response:
+    """POST /v1/wallet/topup with the swap layer mocked at the mint boundary.
+
+    The conftest's testmint stub for recieve_token is swapped back for the
+    real implementation so the request exercises the actual swap path.
+    """
+    with patch("routstr.wallet.recieve_token", _real_recieve_token):
+        with patch(
+            "routstr.wallet.deserialize_token_from_string", return_value=mock_token
+        ):
+            with patch(
+                "routstr.wallet.get_wallet",
+                side_effect=_wallet_router(primary_wallet, token_wallet),
+            ):
+                with patch.object(settings, "primary_mint", PRIMARY_MINT):
+                    with patch.object(settings, "primary_mint_unit", "sat"):
+                        with patch.object(settings, "cashu_mints", [PRIMARY_MINT]):
+                            return await client.post(
+                                "/v1/wallet/topup",
+                                params={"cashu_token": "cashuAtest_foreign_token"},
+                            )
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_topup_retries_when_melt_demands_more_than_quoted(
+    authenticated_client: AsyncClient,
+) -> None:
+    """A 179-sat token where every quote reports fee_reserve=1 but the mint
+    rejects the first melt demanding 180. The retry shrinks the invoice to 177
+    and the topup credits 177 sats (177_000 msats)."""
+    mock_token, token_wallet, primary_wallet = _make_swap_mocks(
+        179, fee_reserves=[1, 1, 1], mint_url="http://mint.cubabitcoin.org"
+    )
+    token_wallet.melt.side_effect = [
+        Exception(
+            "Mint Error: not enough inputs provided for melt. "
+            "Provided: 179, needed: 180 (Code: 11000)"
+        ),
+        Mock(),
+    ]
+
+    response = await _post_topup(
+        authenticated_client, mock_token, token_wallet, primary_wallet
+    )
+
+    assert response.status_code == 200
+    assert response.json()["msats"] == 177_000
+    assert token_wallet.melt.call_count == 2
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_topup_retries_when_quote_fee_exceeds_estimate(
+    authenticated_client: AsyncClient,
+) -> None:
+    """A 1000-sat token estimated at fee 20, but the real quote demands 23.
+    The retry recomputes 1000 - 23 = 977, which fits, and the topup credits
+    977 sats (977_000 msats) with a single melt."""
+    mock_token, token_wallet, primary_wallet = _make_swap_mocks(
+        1000, fee_reserves=[20, 23, 23]
+    )
+
+    response = await _post_topup(
+        authenticated_client, mock_token, token_wallet, primary_wallet
+    )
+
+    assert response.status_code == 200
+    assert response.json()["msats"] == 977_000
+    assert token_wallet.melt.call_count == 1
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_topup_returns_400_when_retries_exhausted(
+    authenticated_client: AsyncClient,
+) -> None:
+    """A mint that escalates fee_reserve on every re-quote (1 → 10 → 25 → 50)
+    exhausts the retry budget: clean 400 with an actionable message, melt never
+    executed."""
+    mock_token, token_wallet, primary_wallet = _make_swap_mocks(
+        1000, fee_reserves=[1, 10, 25, 50]
+    )
+
+    response = await _post_topup(
+        authenticated_client, mock_token, token_wallet, primary_wallet
+    )
+
+    assert response.status_code == 400
+    assert "too small to cover swap fees" in response.json()["detail"]
+    assert token_wallet.melt_quote.call_count == 4  # estimation + 3 attempts
+    token_wallet.melt.assert_not_called()

tests/unit/test_auth_cashu.py

@@ -0,0 +1,59 @@
+import hashlib
+from types import SimpleNamespace
+from typing import AsyncGenerator
+from unittest.mock import AsyncMock, patch
+
+import pytest
+from fastapi import HTTPException
+from sqlalchemy.ext.asyncio import AsyncEngine, create_async_engine
+from sqlalchemy.pool import StaticPool
+from sqlmodel import SQLModel
+from sqlmodel.ext.asyncio.session import AsyncSession
+
+from routstr.auth import validate_bearer_key
+from routstr.core.db import ApiKey
+
+
+def _make_engine() -> AsyncEngine:
+    return create_async_engine(
+        "sqlite+aiosqlite://",
+        poolclass=StaticPool,
+        connect_args={"check_same_thread": False},
+    )
+
+
+@pytest.fixture
+async def session() -> AsyncGenerator[AsyncSession, None]:
+    engine = _make_engine()
+    async with engine.begin() as conn:
+        await conn.run_sync(SQLModel.metadata.create_all)
+    db_session = AsyncSession(engine, expire_on_commit=False)
+    try:
+        yield db_session
+    finally:
+        await db_session.close()
+        await engine.dispose()
+
+
+@pytest.mark.asyncio
+async def test_failed_first_cashu_redemption_rolls_back_empty_api_key(
+    session: AsyncSession,
+) -> None:
+    token = "cashuAfirst_seen_but_redemption_fails"
+    hashed_key = hashlib.sha256(token.encode()).hexdigest()
+    token_obj = SimpleNamespace(mint="http://mint:3338", unit="sat")
+
+    from routstr.core.settings import settings
+
+    with (
+        patch.object(settings, "cashu_mints", ["http://mint:3338"]),
+        patch("routstr.auth.deserialize_token_from_string", return_value=token_obj),
+        patch(
+            "routstr.auth.credit_balance",
+            new=AsyncMock(side_effect=ValueError("token already spent")),
+        ),
+    ):
+        with pytest.raises(HTTPException):
+            await validate_bearer_key(token, session)
+
+    assert await session.get(ApiKey, hashed_key) is None

tests/unit/test_cache_breakpoints.py

@@ -0,0 +1,189 @@
+"""Tests for Anthropic cache-breakpoint injection on forwarded requests.
+
+Anthropic prompt caching is explicit; a client that doesn't recognise a routstr
+URL as Anthropic-backed never sends ``cache_control`` markers, so caching never
+engages over routstr. ``prepare_request_body`` must stamp the standard
+breakpoints for Anthropic-family models while always deferring to client-set
+markers and never touching automatic-cache providers.
+"""
+
+import json
+import os
+
+import pytest
+
+os.environ.setdefault("UPSTREAM_BASE_URL", "http://test")
+os.environ.setdefault("UPSTREAM_API_KEY", "test")
+os.environ.setdefault("LIGHTNING_ADDRESS", "test@stm.to")
+
+from routstr.upstream import GenericUpstreamProvider
+from routstr.upstream.cache_breakpoints import (
+    body_has_cache_control,
+    inject_anthropic_cache_breakpoints,
+    is_explicit_cache_model,
+)
+
+
+def _chat_body() -> dict:
+    return {
+        "model": "anthropic/claude-sonnet-4.5",
+        "stream": True,
+        "messages": [
+            {"role": "system", "content": "You are concise."},
+            {"role": "user", "content": "Hello"},
+        ],
+        "tools": [
+            {"type": "function", "function": {"name": "a"}},
+            {"type": "function", "function": {"name": "b"}},
+        ],
+    }
+
+
+# ---------------------------------------------------------------------------
+# Model detection
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.parametrize(
+    "model_id,expected",
+    [
+        ("anthropic/claude-sonnet-4.5", True),
+        ("claude-haiku-4-5-20251001", True),
+        # Alibaba explicit-cache models share Anthropic's wire format
+        ("qwen/qwen3-max", True),
+        ("qwen/qwen3-coder-plus", True),
+        ("deepseek/deepseek-v3.2", True),
+        # Automatic-cache providers need no markers
+        ("openai/gpt-4o", False),
+        ("google/gemini-2.5-flash", False),
+        ("deepseek/deepseek-chat", False),
+        ("qwen/qwen3.5-plus-02-15", False),  # snapshot, no explicit caching
+        (None, False),
+    ],
+)
+def test_is_explicit_cache_model(model_id: str | None, expected: bool) -> None:
+    assert is_explicit_cache_model(model_id) is expected
+
+
+def test_is_explicit_cache_model_uses_fallbacks() -> None:
+    # routstr id is opaque but a forwarded/canonical alias reveals the family.
+    assert is_explicit_cache_model("model-xyz", None, "anthropic/claude-opus-4.1")
+
+
+# ---------------------------------------------------------------------------
+# Breakpoint placement
+# ---------------------------------------------------------------------------
+
+
+def test_injects_three_breakpoints() -> None:
+    data = _chat_body()
+    assert inject_anthropic_cache_breakpoints(data) is True
+
+    # system prompt promoted to array form with a marker
+    system = data["messages"][0]["content"]
+    assert system == [
+        {
+            "type": "text",
+            "text": "You are concise.",
+            "cache_control": {"type": "ephemeral"},
+        }
+    ]
+    # last tool marked
+    assert data["tools"][-1]["cache_control"] == {"type": "ephemeral"}
+    assert "cache_control" not in data["tools"][0]
+    # last user message marked
+    user = data["messages"][1]["content"]
+    assert user[-1]["cache_control"] == {"type": "ephemeral"}
+
+
+def test_defers_to_client_supplied_cache_control() -> None:
+    data = _chat_body()
+    data["messages"][1]["content"] = [
+        {"type": "text", "text": "Hello", "cache_control": {"type": "ephemeral"}}
+    ]
+    assert body_has_cache_control(data) is True
+    # No additional stamping when the client already controls caching.
+    assert inject_anthropic_cache_breakpoints(data) is False
+    assert "cache_control" not in data["tools"][-1]
+
+
+def test_marks_last_text_part_of_array_content() -> None:
+    data = _chat_body()
+    data["messages"][1]["content"] = [
+        {"type": "text", "text": "first"},
+        {"type": "image_url", "image_url": {"url": "x"}},
+        {"type": "text", "text": "last"},
+    ]
+    inject_anthropic_cache_breakpoints(data)
+    parts = data["messages"][1]["content"]
+    assert parts[2]["cache_control"] == {"type": "ephemeral"}
+    assert "cache_control" not in parts[0]
+
+
+def test_noop_without_messages() -> None:
+    assert inject_anthropic_cache_breakpoints({"prompt": "x"}) is False
+
+
+# ---------------------------------------------------------------------------
+# prepare_request_body integration
+# ---------------------------------------------------------------------------
+
+
+def _model(model_id: str):  # type: ignore[no-untyped-def]
+    from routstr.payment.models import Architecture, Model, Pricing
+
+    return Model(
+        id=model_id,
+        name=model_id,
+        created=0,
+        description="",
+        context_length=200000,
+        architecture=Architecture(
+            modality="text->text",
+            input_modalities=["text"],
+            output_modalities=["text"],
+            tokenizer="Claude",
+            instruct_type=None,
+        ),
+        pricing=Pricing(prompt=0.0, completion=0.0),
+    )
+
+
+def _openrouter_provider() -> "GenericUpstreamProvider":
+    # OpenRouter endpoint via the generic provider — recognised by base URL.
+    return GenericUpstreamProvider(base_url="https://openrouter.ai/api/v1")
+
+
+@pytest.mark.parametrize(
+    "model_id", ["anthropic/claude-sonnet-4.5", "qwen/qwen3-max", "deepseek/deepseek-v3.2"]
+)
+def test_prepare_request_body_injects_for_explicit_models(model_id: str) -> None:
+    provider = _openrouter_provider()
+    body = json.dumps(_chat_body()).encode()
+    out = provider.prepare_request_body(body, _model(model_id))
+    assert out is not None
+    data = json.loads(out)
+    assert body_has_cache_control(data) is True
+    assert data["tools"][-1]["cache_control"] == {"type": "ephemeral"}
+
+
+def test_prepare_request_body_skips_for_automatic_provider_model() -> None:
+    provider = _openrouter_provider()
+    body = json.dumps(_chat_body()).encode()
+    out = provider.prepare_request_body(body, _model("openai/gpt-4o"))
+    assert out is not None
+    data = json.loads(out)
+    assert body_has_cache_control(data) is False
+
+
+def test_prepare_request_body_skips_when_upstream_rejects_markers() -> None:
+    # Claude id but a non-OpenRouter/Anthropic upstream → must NOT inject,
+    # since the markers could be rejected by an upstream that doesn't accept them.
+    from routstr.upstream import GenericUpstreamProvider
+
+    provider = GenericUpstreamProvider(base_url="https://some-gateway.example/v1")
+    body = json.dumps(_chat_body()).encode()
+    out = provider.prepare_request_body(body, _model("anthropic/claude-sonnet-4.5"))
+    assert out is not None
+    data = json.loads(out)
+    assert body_has_cache_control(data) is False

tests/unit/test_cache_pricing.py

@@ -0,0 +1,245 @@
+"""Tests for cache-aware pricing of cached input tokens.
+
+Specifies two things:
+
+1. ``backfill_cache_pricing`` — when the OpenRouter model feed omits cache
+   rates (it does for most DeepSeek models and e.g. openai/gpt-4o), they are
+   filled from litellm's bundled cost map instead of silently billing cache
+   reads at the full input rate. Existing OpenRouter values are never
+   overwritten, and provider fees apply to backfilled rates like any other.
+2. ``calculate_cost`` — cached tokens are billed at the cache rates from the
+   model's sats_pricing; the full input rate remains only as the documented
+   last resort when no cache rate could be resolved anywhere.
+"""
+
+import os
+from unittest.mock import Mock, patch
+
+import litellm
+import pytest
+
+os.environ.setdefault("UPSTREAM_BASE_URL", "http://test")
+os.environ.setdefault("UPSTREAM_API_KEY", "test")
+os.environ.setdefault("LIGHTNING_ADDRESS", "test@stm.to")
+
+from routstr.core.settings import settings
+from routstr.payment.cost_calculation import CostData, calculate_cost
+from routstr.payment.models import (
+    Architecture,
+    Model,
+    Pricing,
+    backfill_cache_pricing,
+)
+from routstr.upstream import GenericUpstreamProvider
+
+
+def _make_model(model_id: str, pricing: Pricing) -> Model:
+    return Model(
+        id=model_id,
+        name=model_id,
+        created=0,
+        description="",
+        context_length=64000,
+        architecture=Architecture(
+            modality="text->text",
+            input_modalities=["text"],
+            output_modalities=["text"],
+            tokenizer="Other",
+            instruct_type=None,
+        ),
+        pricing=pricing,
+    )
+
+
+# ============================================================================
+# backfill_cache_pricing — litellm as fallback source for missing cache rates
+# ============================================================================
+
+
+def test_backfill_deepseek_cache_read_from_litellm() -> None:
+    """deepseek/deepseek-chat has no input_cache_read on OpenRouter; litellm
+    knows the real rate (10x cheaper than input)."""
+    pricing = Pricing(prompt=2.8e-07, completion=4.2e-07)
+
+    result = backfill_cache_pricing("deepseek/deepseek-chat", pricing)
+
+    expected = litellm.model_cost["deepseek/deepseek-chat"][
+        "cache_read_input_token_cost"
+    ]
+    assert result.input_cache_read == expected
+    assert result.input_cache_read < pricing.prompt  # sanity: it's a discount
+
+
+def test_backfill_strips_vendor_prefix_for_litellm_lookup() -> None:
+    """OpenRouter ids are vendor-prefixed (openai/gpt-4o); litellm keys most
+    non-DeepSeek models without the prefix (gpt-4o)."""
+    pricing = Pricing(prompt=2.5e-06, completion=1e-05)
+
+    result = backfill_cache_pricing("openai/gpt-4o", pricing)
+
+    expected = litellm.model_cost["gpt-4o"]["cache_read_input_token_cost"]
+    assert result.input_cache_read == expected
+
+
+def test_backfill_fills_cache_write_rate() -> None:
+    """Anthropic cache writes cost more than input (1.25x); billing them at
+    the input rate undercharges. litellm carries the write rate."""
+    pricing = Pricing(prompt=3e-06, completion=1.5e-05)
+
+    result = backfill_cache_pricing("anthropic/claude-sonnet-4-5", pricing)
+
+    expected = litellm.model_cost["claude-sonnet-4-5"][
+        "cache_creation_input_token_cost"
+    ]
+    assert result.input_cache_write == expected
+    assert result.input_cache_write > pricing.prompt  # sanity: write premium
+
+
+def test_backfill_never_overwrites_openrouter_rates() -> None:
+    """When OpenRouter provides a cache rate, it is authoritative."""
+    pricing = Pricing(
+        prompt=2.1e-07, completion=7.9e-07, input_cache_read=1.3e-07
+    )
+
+    result = backfill_cache_pricing("deepseek/deepseek-chat", pricing)
+
+    assert result.input_cache_read == 1.3e-07
+
+
+def test_backfill_unknown_model_unchanged() -> None:
+    """Models litellm doesn't know stay untouched (last-resort fallback to
+    the input rate happens later, at billing time)."""
+    pricing = Pricing(prompt=1e-06, completion=2e-06)
+
+    result = backfill_cache_pricing("artificial-dumbness/dumb-1", pricing)
+
+    assert result.input_cache_read == 0.0
+    assert result.input_cache_write == 0.0
+
+
+def test_provider_fee_applies_to_backfilled_cache_rates() -> None:
+    """Backfill happens before the provider fee, so cache rates carry the
+    same markup as every other price component."""
+    provider = GenericUpstreamProvider(
+        base_url="http://upstream.example", provider_fee=2.0
+    )
+    model = _make_model(
+        "deepseek/deepseek-chat", Pricing(prompt=2.8e-07, completion=4.2e-07)
+    )
+
+    adjusted = provider._apply_provider_fee_to_model(model)
+
+    litellm_read = litellm.model_cost["deepseek/deepseek-chat"][
+        "cache_read_input_token_cost"
+    ]
+    assert adjusted.pricing.input_cache_read == pytest.approx(litellm_read * 2.0)
+    assert adjusted.pricing.prompt == pytest.approx(2.8e-07 * 2.0)
+
+
+# ============================================================================
+# calculate_cost — cached tokens billed at cache rates
+# ============================================================================
+
+
+@pytest.fixture(autouse=True)
+def patch_sats_usd_price() -> None:  # type: ignore[misc]
+    with patch("routstr.payment.cost_calculation.sats_usd_price", return_value=5.0e-5):
+        yield
+
+
+@pytest.fixture
+def model_pricing(monkeypatch: pytest.MonkeyPatch) -> Mock:
+    """Model-based pricing: 1 msat per input token, 2 per output token,
+    0.1 per cache-read token, 1.25 per cache-write token."""
+    monkeypatch.setattr(settings, "fixed_pricing", False)
+    model = Mock()
+    model.sats_pricing = Pricing(
+        prompt=0.001,
+        completion=0.002,
+        input_cache_read=0.0001,
+        input_cache_write=0.00125,
+    )
+    return model
+
+
+@pytest.mark.asyncio
+async def test_deepseek_cache_hits_billed_at_cache_rate(model_pricing: Mock) -> None:
+    """The reported overcharge scenario: a 10k-token prompt with 90% cache
+    hits costs 2900 msats at honest rates, not the 11000 msats that billing
+    every prompt token at the full input rate would charge."""
+    response = {
+        "model": "deepseek-chat",
+        "usage": {
+            "prompt_tokens": 10000,
+            "completion_tokens": 500,
+            "prompt_cache_hit_tokens": 9000,
+            "prompt_cache_miss_tokens": 1000,
+        },
+    }
+
+    with patch("routstr.proxy.get_model_instance", return_value=model_pricing):
+        result = await calculate_cost(response, max_cost=100000)
+
+    assert isinstance(result, CostData)
+    # 1000 input @ 1 msat + 9000 cache reads @ 0.1 msat + 500 output @ 2 msat.
+    # input_msats folds the cache-read cost in (1000 + 900) so a dashboard
+    # rendering I/O/T sees input + output == total; the cache portion stays
+    # visible in cache_read_msats.
+    assert result.cache_read_msats == 900
+    assert result.output_msats == 1000
+    assert result.input_msats == 1900
+    assert result.input_msats + result.output_msats == result.total_msats
+    assert result.total_msats == 2900
+
+
+@pytest.mark.asyncio
+async def test_anthropic_cache_write_billed_at_write_rate(model_pricing: Mock) -> None:
+    """Cache writes carry their premium rate (1.25x input here), instead of
+    being silently billed at the plain input rate."""
+    response = {
+        "model": "claude-sonnet-4-5",
+        "usage": {
+            "input_tokens": 300,
+            "output_tokens": 100,
+            "cache_read_input_tokens": 500,
+            "cache_creation_input_tokens": 2000,
+        },
+    }
+
+    with patch("routstr.proxy.get_model_instance", return_value=model_pricing):
+        result = await calculate_cost(response, max_cost=100000)
+
+    assert isinstance(result, CostData)
+    # 300 @ 1 + 500 @ 0.1 + 2000 @ 1.25 + 100 @ 2
+    assert result.cache_read_msats == 50
+    assert result.cache_creation_msats == 2500
+    assert result.total_msats == 3050
+
+
+@pytest.mark.asyncio
+async def test_missing_cache_rate_falls_back_to_input_rate(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Documented last resort: when no cache rate could be resolved anywhere
+    (OpenRouter and litellm both silent), cache reads bill at the input rate —
+    never cheaper, never free."""
+    monkeypatch.setattr(settings, "fixed_pricing", False)
+    model = Mock()
+    model.sats_pricing = Pricing(prompt=0.001, completion=0.002)
+
+    response = {
+        "model": "dumb-1",
+        "usage": {
+            "prompt_tokens": 10000,
+            "completion_tokens": 500,
+            "prompt_cache_hit_tokens": 9000,
+            "prompt_cache_miss_tokens": 1000,
+        },
+    }
+
+    with patch("routstr.proxy.get_model_instance", return_value=model):
+        result = await calculate_cost(response, max_cost=100000)
+
+    assert isinstance(result, CostData)
+    # 1000 @ 1 + 9000 @ 1 (fallback) + 500 @ 2
+    assert result.total_msats == 11000

tests/unit/test_cost_calculation_caching.py

@@ -1,10 +1,11 @@
 """Tests for cache token handling in cost calculation.
 
-Covers OpenAI vs Anthropic caching formats, edge cases, and billing accuracy.
+Covers OpenAI, Anthropic and DeepSeek caching formats, dialect precedence,
+edge cases, and billing accuracy.
 """
 
 import os
-from unittest.mock import AsyncMock, patch
+from unittest.mock import patch
 
 import pytest
 
@@ -16,12 +17,6 @@ from routstr.core.settings import settings
 from routstr.payment.cost_calculation import CostData, MaxCostData, calculate_cost
 
 
-@pytest.fixture
-def mock_session() -> AsyncMock:
-    """Mock AsyncSession for cost calculation tests."""
-    return AsyncMock()
-
-
 @pytest.fixture(autouse=True)
 def mock_fixed_pricing(monkeypatch: pytest.MonkeyPatch) -> None:
     """Mock settings and price to use fixed pricing."""
@@ -41,7 +36,7 @@ def patch_sats_usd_price() -> None:  # type: ignore[misc]
 # Test 1: OpenAI Cache Format
 # ============================================================================
 @pytest.mark.asyncio
-async def test_openai_cache_subtraction(mock_session: AsyncMock) -> None:
+async def test_openai_cache_subtraction() -> None:
     """OpenAI includes cached_tokens in prompt_tokens, subtract them."""
     response = {
         "model": "gpt-4",
@@ -53,7 +48,7 @@ async def test_openai_cache_subtraction(mock_session: AsyncMock) -> None:
             }
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, CostData)
     assert result.input_tokens == 1000  # 2000 - 1000
@@ -65,7 +60,7 @@ async def test_openai_cache_subtraction(mock_session: AsyncMock) -> None:
 # Test 2: Anthropic Cache Format
 # ============================================================================
 @pytest.mark.asyncio
-async def test_anthropic_cache_additive(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_anthropic_cache_additive(mock_fixed_pricing: None) -> None:
     """Anthropic cache tokens are separate (additive) from input_tokens."""
     response = {
         "model": "claude-3-5-sonnet",
@@ -76,7 +71,7 @@ async def test_anthropic_cache_additive(mock_session: AsyncMock, mock_fixed_pric
             "cache_read_input_tokens": 0,
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, CostData)
     assert result.input_tokens == 500
@@ -89,7 +84,7 @@ async def test_anthropic_cache_additive(mock_session: AsyncMock, mock_fixed_pric
 # Test 3: Invalid Cache (Edge Case)
 # ============================================================================
 @pytest.mark.asyncio
-async def test_cache_read_exceeds_prompt_tokens(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_cache_read_exceeds_prompt_tokens(mock_fixed_pricing: None) -> None:
     """Handle buggy upstream reporting cached > prompt_tokens."""
     response = {
         "model": "gpt-4",
@@ -101,7 +96,7 @@ async def test_cache_read_exceeds_prompt_tokens(mock_session: AsyncMock, mock_fi
             }
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     # Should not go negative
     assert isinstance(result, CostData)
@@ -114,7 +109,7 @@ async def test_cache_read_exceeds_prompt_tokens(mock_session: AsyncMock, mock_fi
 # Test 4: Malformed Token Values
 # ============================================================================
 @pytest.mark.asyncio
-async def test_malformed_cache_tokens_coerce_to_zero(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_malformed_cache_tokens_coerce_to_zero(mock_fixed_pricing: None) -> None:
     """Handle non-numeric cache token values."""
     response = {
         "model": "gpt-4",
@@ -127,7 +122,7 @@ async def test_malformed_cache_tokens_coerce_to_zero(mock_session: AsyncMock, mo
             }
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     # Both should coerce to 0
     assert isinstance(result, CostData)
@@ -139,7 +134,7 @@ async def test_malformed_cache_tokens_coerce_to_zero(mock_session: AsyncMock, mo
 # Test 5: Anthropic Cache Not Subtracted
 # ============================================================================
 @pytest.mark.asyncio
-async def test_anthropic_cache_not_subtracted(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_anthropic_cache_not_subtracted(mock_fixed_pricing: None) -> None:
     """Anthropic cache fields should NOT be subtracted from input_tokens."""
     response = {
         "model": "claude-3-5-sonnet",
@@ -149,7 +144,7 @@ async def test_anthropic_cache_not_subtracted(mock_session: AsyncMock, mock_fixe
             "cache_read_input_tokens": 200,  # ← Additive, don't subtract
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     # Anthropic: input_tokens stays as-is
     assert isinstance(result, CostData)
@@ -161,7 +156,7 @@ async def test_anthropic_cache_not_subtracted(mock_session: AsyncMock, mock_fixe
 # Test 6: Only Cache Read, No Regular Input
 # ============================================================================
 @pytest.mark.asyncio
-async def test_only_cache_read_tokens(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_only_cache_read_tokens(mock_fixed_pricing: None) -> None:
     """Handle response with only cache read tokens."""
     response = {
         "model": "gpt-4",
@@ -173,7 +168,7 @@ async def test_only_cache_read_tokens(mock_session: AsyncMock, mock_fixed_pricin
             }
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, CostData)
     assert result.input_tokens == 0  # max(0, 0 - 1000)
@@ -185,7 +180,7 @@ async def test_only_cache_read_tokens(mock_session: AsyncMock, mock_fixed_pricin
 # Test 7: Only Cache Creation
 # ============================================================================
 @pytest.mark.asyncio
-async def test_only_cache_creation_tokens(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_only_cache_creation_tokens(mock_fixed_pricing: None) -> None:
     """Handle response with only cache creation tokens (Anthropic)."""
     response = {
         "model": "claude-3-5-sonnet",
@@ -196,7 +191,7 @@ async def test_only_cache_creation_tokens(mock_session: AsyncMock, mock_fixed_pr
             "cache_read_input_tokens": 0,
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, CostData)
     assert result.input_tokens == 500
@@ -209,7 +204,7 @@ async def test_only_cache_creation_tokens(mock_session: AsyncMock, mock_fixed_pr
 # Test 8: Both Cache Read and Creation
 # ============================================================================
 @pytest.mark.asyncio
-async def test_both_cache_read_and_creation(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_both_cache_read_and_creation(mock_fixed_pricing: None) -> None:
     """Handle response with both cache read and creation."""
     response = {
         "model": "claude-3-5-sonnet",
@@ -220,7 +215,7 @@ async def test_both_cache_read_and_creation(mock_session: AsyncMock, mock_fixed_
             "cache_read_input_tokens": 500,
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, CostData)
     assert result.input_tokens == 300
@@ -233,7 +228,7 @@ async def test_both_cache_read_and_creation(mock_session: AsyncMock, mock_fixed_
 # Test 9: Token Field Fallback
 # ============================================================================
 @pytest.mark.asyncio
-async def test_token_field_fallback_order(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_token_field_fallback_order(mock_fixed_pricing: None) -> None:
     """Verify fallback order for token extraction."""
     # When prompt_tokens is not present, fall back to input_tokens
     response = {
@@ -243,7 +238,7 @@ async def test_token_field_fallback_order(mock_session: AsyncMock, mock_fixed_pr
             "completion_tokens": 50,
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, CostData)
     assert result.input_tokens == 250
@@ -254,20 +249,21 @@ async def test_token_field_fallback_order(mock_session: AsyncMock, mock_fixed_pr
 # Test 10: Float Token Values
 # ============================================================================
 @pytest.mark.asyncio
-async def test_float_token_values_coerced_to_int(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_float_token_values_coerced_to_int(mock_fixed_pricing: None) -> None:
     """Handle float token values by converting to int."""
     response = {
         "model": "gpt-4",
         "usage": {
             "prompt_tokens": 100.7,  # Float
             "completion_tokens": 50.3,  # Float
-            "cache_read_input_tokens": 25.9,  # Float
+            "prompt_tokens_details": {"cached_tokens": 25.9},  # Float
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, CostData)
-    assert result.input_tokens == 100  # Floored
+    # cached_tokens are part of prompt_tokens (OpenAI dialect) → subtracted: 100 - 25
+    assert result.input_tokens == 75  # Floored
     assert result.output_tokens == 50  # Floored
     assert result.cache_read_input_tokens == 25  # Floored
 
@@ -276,7 +272,7 @@ async def test_float_token_values_coerced_to_int(mock_session: AsyncMock, mock_f
 # Test 11: Boolean Cache Tokens
 # ============================================================================
 @pytest.mark.asyncio
-async def test_boolean_cache_tokens_coerced_to_zero(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_boolean_cache_tokens_coerced_to_zero(mock_fixed_pricing: None) -> None:
     """Handle boolean cache token values by coercing to zero."""
     response = {
         "model": "gpt-4",
@@ -286,7 +282,7 @@ async def test_boolean_cache_tokens_coerced_to_zero(mock_session: AsyncMock, moc
             "cache_read_input_tokens": True,  # Boolean
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, CostData)
     assert result.cache_read_input_tokens == 0  # Boolean coerced to 0
@@ -297,7 +293,7 @@ async def test_boolean_cache_tokens_coerced_to_zero(mock_session: AsyncMock, moc
 # Test 12: Zero Cache Tokens
 # ============================================================================
 @pytest.mark.asyncio
-async def test_zero_cache_tokens(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_zero_cache_tokens(mock_fixed_pricing: None) -> None:
     """Handle explicit zero cache tokens."""
     response = {
         "model": "gpt-4",
@@ -309,21 +305,113 @@ async def test_zero_cache_tokens(mock_session: AsyncMock, mock_fixed_pricing: No
             }
         }
     }
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, CostData)
     assert result.cache_read_input_tokens == 0
     assert result.input_tokens == 100
 
 
+# ============================================================================
+# DeepSeek Cache Format
+# DeepSeek emits neither OpenAI's prompt_tokens_details nor Anthropic's
+# cache_read_input_tokens — only prompt_cache_hit_tokens and
+# prompt_cache_miss_tokens, with the documented guarantee
+# prompt_tokens = hit + miss. Hits are ~10x cheaper upstream, so billing
+# them as regular input is a large overcharge.
+# ============================================================================
+@pytest.mark.asyncio
+async def test_deepseek_cache_hit_tokens_extracted() -> None:
+    """DeepSeek cache hits are extracted and removed from regular input.
+
+    Payload shape verbatim from the DeepSeek API reference (usage object).
+    """
+    response = {
+        "model": "deepseek-chat",
+        "usage": {
+            "prompt_tokens": 10000,  # = hit + miss
+            "completion_tokens": 500,
+            "total_tokens": 10500,
+            "prompt_cache_hit_tokens": 9000,
+            "prompt_cache_miss_tokens": 1000,
+        },
+    }
+    result = await calculate_cost(response, max_cost=100000)
+
+    assert isinstance(result, CostData)
+    assert result.input_tokens == 1000  # only the cache misses
+    assert result.cache_read_input_tokens == 9000
+    assert result.output_tokens == 500
+
+
+@pytest.mark.asyncio
+async def test_deepseek_all_tokens_cached() -> None:
+    """A fully cached DeepSeek prompt bills zero regular input tokens."""
+    response = {
+        "model": "deepseek-chat",
+        "usage": {
+            "prompt_tokens": 5000,
+            "completion_tokens": 100,
+            "prompt_cache_hit_tokens": 5000,
+            "prompt_cache_miss_tokens": 0,
+        },
+    }
+    result = await calculate_cost(response, max_cost=100000)
+
+    assert isinstance(result, CostData)
+    assert result.input_tokens == 0
+    assert result.cache_read_input_tokens == 5000
+
+
+@pytest.mark.asyncio
+async def test_dialect_precedence_never_double_subtracts() -> None:
+    """If a vendor emits both OpenAI-style and DeepSeek-style cache fields for
+    the same cached tokens, they are counted once, not subtracted twice."""
+    response = {
+        "model": "deepseek-chat",
+        "usage": {
+            "prompt_tokens": 10000,
+            "completion_tokens": 500,
+            "prompt_tokens_details": {"cached_tokens": 9000},
+            "prompt_cache_hit_tokens": 9000,
+            "prompt_cache_miss_tokens": 1000,
+        },
+    }
+    result = await calculate_cost(response, max_cost=100000)
+
+    assert isinstance(result, CostData)
+    assert result.input_tokens == 1000  # 10000 - 9000, applied exactly once
+    assert result.cache_read_input_tokens == 9000
+
+
+@pytest.mark.asyncio
+async def test_deepseek_malformed_hit_tokens_coerce_to_zero() -> None:
+    """Malformed DeepSeek cache fields degrade to billing all input at full
+    rate instead of crashing or going negative."""
+    response = {
+        "model": "deepseek-chat",
+        "usage": {
+            "prompt_tokens": 1000,
+            "completion_tokens": 50,
+            "prompt_cache_hit_tokens": "garbage",
+            "prompt_cache_miss_tokens": -5,
+        },
+    }
+    result = await calculate_cost(response, max_cost=100000)
+
+    assert isinstance(result, CostData)
+    assert result.input_tokens == 1000
+    assert result.cache_read_input_tokens == 0
+
+
 # ============================================================================
 # Test 13: Missing Usage Block
 # ============================================================================
 @pytest.mark.asyncio
-async def test_missing_usage_block(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_missing_usage_block(mock_fixed_pricing: None) -> None:
     """When usage is missing, return MaxCostData with zero tokens."""
     response = {"model": "gpt-4", "choices": [{"message": {"content": "test"}}]}
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, MaxCostData)
     assert result.input_tokens == 0
@@ -335,10 +423,10 @@ async def test_missing_usage_block(mock_session: AsyncMock, mock_fixed_pricing:
 # Test 14: Null Usage Block
 # ============================================================================
 @pytest.mark.asyncio
-async def test_null_usage_block(mock_session: AsyncMock, mock_fixed_pricing: None) -> None:
+async def test_null_usage_block(mock_fixed_pricing: None) -> None:
     """When usage is null, return MaxCostData with zero tokens."""
     response = {"model": "gpt-4", "usage": None}
-    result = await calculate_cost(response, max_cost=100000, session=mock_session)
+    result = await calculate_cost(response, max_cost=100000)
 
     assert isinstance(result, MaxCostData)
     assert result.input_tokens == 0

tests/unit/test_fetch_all_balances.py

@@ -0,0 +1,73 @@
+from contextlib import asynccontextmanager
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from routstr.wallet import fetch_all_balances
+
+
+@asynccontextmanager
+async def _fake_session():  # type: ignore[no-untyped-def]
+    yield MagicMock()
+
+
+def _patches(proof_amount: int = 1000):  # type: ignore[no-untyped-def]
+    proof = MagicMock(amount=proof_amount)
+    return [
+        patch("routstr.wallet.get_wallet", AsyncMock(return_value=MagicMock())),
+        patch(
+            "routstr.wallet.get_proofs_per_mint_and_unit",
+            MagicMock(return_value=[proof]),
+        ),
+        patch(
+            "routstr.wallet.slow_filter_spend_proofs",
+            AsyncMock(side_effect=lambda proofs, wallet: proofs),
+        ),
+        patch(
+            "routstr.wallet.db.balances_for_mint_and_unit",
+            AsyncMock(return_value=0),
+        ),
+        patch("routstr.wallet.db.create_session", _fake_session),
+    ]
+
+
+@pytest.mark.asyncio
+async def test_fetch_all_balances_falls_back_to_primary_mint() -> None:
+    """With empty cashu_mints, balances are still fetched for primary_mint."""
+    from routstr.core.settings import settings
+
+    with patch.object(settings, "cashu_mints", []), patch.object(
+        settings, "primary_mint", "http://primary:3338"
+    ):
+        for p in _patches(proof_amount=1000):
+            p.start()
+        try:
+            details, total_wallet, total_user, owner = await fetch_all_balances(
+                units=["sat"]
+            )
+        finally:
+            patch.stopall()
+
+    assert [d["mint_url"] for d in details] == ["http://primary:3338"]
+    assert total_wallet == 1000
+
+
+@pytest.mark.asyncio
+async def test_fetch_all_balances_no_duplicate_primary_mint() -> None:
+    """primary_mint already in cashu_mints is not inspected twice."""
+    from routstr.core.settings import settings
+
+    with patch.object(
+        settings, "cashu_mints", ["http://primary:3338"]
+    ), patch.object(settings, "primary_mint", "http://primary:3338"):
+        for p in _patches(proof_amount=1000):
+            p.start()
+        try:
+            details, total_wallet, _total_user, _owner = await fetch_all_balances(
+                units=["sat"]
+            )
+        finally:
+            patch.stopall()
+
+    assert [d["mint_url"] for d in details] == ["http://primary:3338"]
+    assert total_wallet == 1000

tests/unit/test_messages_litellm_dispatch.py

@@ -500,7 +500,7 @@ async def test_streaming_emits_sse_and_reconciles_cost_at_end() -> None:
     captured_cost_call: dict[str, Any] = {}
 
     async def fake_adjust(
-        fresh_key: Any, combined_data: Any, sess: Any, max_cost: int
+        fresh_key: Any, combined_data: Any, sess: Any, max_cost: int, usage: Any = None
     ) -> dict:
         captured_cost_call["combined_data"] = combined_data
         captured_cost_call["max_cost"] = max_cost
@@ -589,7 +589,7 @@ async def test_streaming_handles_iterator_yielding_raw_sse_bytes() -> None:
     captured: dict[str, Any] = {}
 
     async def fake_adjust(
-        fresh_key: Any, combined_data: Any, sess: Any, max_cost: int
+        fresh_key: Any, combined_data: Any, sess: Any, max_cost: int, usage: Any = None
     ) -> dict:
         captured["combined_data"] = combined_data
         return fake_cost

tests/unit/test_require_parameters.py

@@ -0,0 +1,95 @@
+import json
+import os
+
+os.environ.setdefault("UPSTREAM_BASE_URL", "http://test")
+os.environ.setdefault("UPSTREAM_API_KEY", "test")
+os.environ.setdefault("LIGHTNING_ADDRESS", "test@stm.to")
+
+from routstr.upstream import GenericUpstreamProvider
+from routstr.upstream.openrouter import OpenRouterUpstreamProvider
+
+
+def _model(model_id: str = "openai/gpt-4o"):  # type: ignore[no-untyped-def]
+    from routstr.payment.models import Architecture, Model, Pricing
+
+    return Model(
+        id=model_id,
+        name=model_id,
+        created=0,
+        description="",
+        context_length=128000,
+        architecture=Architecture(
+            modality="text->text",
+            input_modalities=["text"],
+            output_modalities=["text"],
+            tokenizer="GPT",
+            instruct_type=None,
+        ),
+        pricing=Pricing(prompt=0.0, completion=0.0),
+    )
+
+
+def _tool_body() -> dict:
+    return {
+        "model": "openai/gpt-4o",
+        "messages": [{"role": "user", "content": "What's the weather?"}],
+        "tools": [
+            {
+                "type": "function",
+                "function": {"name": "get_weather", "parameters": {}},
+            }
+        ],
+    }
+
+
+def _prepare(provider, body: dict) -> dict:  # type: ignore[no-untyped-def]
+    out = provider.prepare_request_body(json.dumps(body).encode(), _model())
+    assert out is not None
+    return json.loads(out)
+
+
+def test_injects_require_parameters_for_tool_request() -> None:
+    data = _prepare(OpenRouterUpstreamProvider(api_key="test"), _tool_body())
+    assert data["provider"]["require_parameters"] is True
+
+
+def test_generic_provider_on_openrouter_url_is_left_alone() -> None:
+    # Only OpenRouterUpstreamProvider injects; a generic provider pointed at the
+    # same base URL doesn't.
+    provider = GenericUpstreamProvider(base_url="https://openrouter.ai/api/v1")
+    data = _prepare(provider, _tool_body())
+    assert "provider" not in data
+
+
+def test_no_injection_without_tools() -> None:
+    body = {"model": "openai/gpt-4o", "messages": [{"role": "user", "content": "hi"}]}
+    data = _prepare(OpenRouterUpstreamProvider(api_key="test"), body)
+    assert "provider" not in data
+
+
+def test_empty_tools_list_does_not_inject() -> None:
+    body = _tool_body()
+    body["tools"] = []
+    data = _prepare(OpenRouterUpstreamProvider(api_key="test"), body)
+    assert "provider" not in data
+
+
+def test_direct_provider_does_not_inject() -> None:
+    provider = GenericUpstreamProvider(base_url="https://api.openai.com/v1")
+    data = _prepare(provider, _tool_body())
+    assert "provider" not in data
+
+
+def test_keeps_client_set_require_parameters() -> None:
+    body = _tool_body()
+    body["provider"] = {"require_parameters": False}
+    data = _prepare(OpenRouterUpstreamProvider(api_key="test"), body)
+    assert data["provider"]["require_parameters"] is False
+
+
+def test_preserves_other_provider_fields() -> None:
+    body = _tool_body()
+    body["provider"] = {"order": ["openai", "azure"]}
+    data = _prepare(OpenRouterUpstreamProvider(api_key="test"), body)
+    assert data["provider"]["order"] == ["openai", "azure"]
+    assert data["provider"]["require_parameters"] is True

tests/unit/test_stale_reservations.py

@@ -0,0 +1,378 @@
+"""Tests for stale reserved_balance handling (issue #551).
+
+Covers:
+- pay_for_request stamping reserved_at on billing and child keys
+- release_stale_reservations sweeper semantics
+- reset_all_reserved_balances clearing reserved_at
+- refund endpoint self-healing stale/legacy reservations
+- proxy reverting the reservation when the client disconnects (CancelledError)
+"""
+
+import asyncio
+import time
+from typing import AsyncGenerator
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+from sqlalchemy.ext.asyncio import AsyncEngine, create_async_engine
+from sqlalchemy.pool import StaticPool
+from sqlmodel import SQLModel
+from sqlmodel.ext.asyncio.session import AsyncSession
+
+from routstr.auth import pay_for_request
+from routstr.balance import refund_wallet_endpoint
+from routstr.core.db import (
+    ApiKey,
+    release_stale_reservations,
+    reset_all_reserved_balances,
+)
+
+
+def _make_engine() -> AsyncEngine:
+    return create_async_engine(
+        "sqlite+aiosqlite://",
+        poolclass=StaticPool,
+        connect_args={"check_same_thread": False},
+    )
+
+
+@pytest.fixture
+async def session() -> "AsyncGenerator[AsyncSession, None]":
+    engine = _make_engine()
+    async with engine.begin() as conn:
+        await conn.run_sync(SQLModel.metadata.create_all)
+    db_session = AsyncSession(engine, expire_on_commit=False)
+    try:
+        yield db_session
+    finally:
+        await db_session.close()
+        await engine.dispose()
+
+
+# ---------------------------------------------------------------------------
+# pay_for_request stamps reserved_at
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_pay_for_request_sets_reserved_at(session: AsyncSession) -> None:
+    key = ApiKey(hashed_key="paykey", balance=10_000)
+    session.add(key)
+    await session.commit()
+
+    before = int(time.time())
+    await pay_for_request(key, 1_000, session)
+
+    await session.refresh(key)
+    assert key.reserved_balance == 1_000
+    assert key.reserved_at is not None
+    assert key.reserved_at >= before
+
+
+@pytest.mark.asyncio
+async def test_pay_for_request_sets_reserved_at_on_child_key(session: AsyncSession) -> None:
+    parent = ApiKey(hashed_key="parentkey", balance=10_000)
+    child = ApiKey(hashed_key="childkey", balance=0, parent_key_hash="parentkey")
+    session.add(parent)
+    session.add(child)
+    await session.commit()
+
+    await pay_for_request(child, 1_000, session)
+
+    await session.refresh(parent)
+    await session.refresh(child)
+    assert parent.reserved_balance == 1_000
+    assert parent.reserved_at is not None
+    assert child.reserved_balance == 1_000
+    assert child.reserved_at is not None
+
+
+@pytest.mark.asyncio
+async def test_revert_clears_reserved_at_when_fully_released(
+    session: AsyncSession,
+) -> None:
+    from routstr.auth import revert_pay_for_request
+
+    key = ApiKey(hashed_key="revertkey", balance=10_000)
+    session.add(key)
+    await session.commit()
+
+    await pay_for_request(key, 1_000, session)
+    reverted = await revert_pay_for_request(key, session, 1_000)
+
+    assert reverted is True
+    await session.refresh(key)
+    assert key.reserved_balance == 0
+    assert key.reserved_at is None
+
+
+@pytest.mark.asyncio
+async def test_revert_keeps_reserved_at_while_other_reservations_remain(
+    session: AsyncSession,
+) -> None:
+    from routstr.auth import revert_pay_for_request
+
+    key = ApiKey(hashed_key="partialrevert", balance=10_000)
+    session.add(key)
+    await session.commit()
+
+    await pay_for_request(key, 1_000, session)
+    await pay_for_request(key, 1_000, session)
+    reverted = await revert_pay_for_request(key, session, 1_000)
+
+    assert reverted is True
+    await session.refresh(key)
+    assert key.reserved_balance == 1_000
+    assert key.reserved_at is not None
+
+
+# ---------------------------------------------------------------------------
+# release_stale_reservations sweeper
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_release_stale_reservations_releases_old(session: AsyncSession) -> None:
+    key = ApiKey(
+        hashed_key="stalekey",
+        balance=5_000,
+        reserved_balance=1_000,
+        reserved_at=int(time.time()) - 1_000,
+    )
+    session.add(key)
+    await session.commit()
+
+    released = await release_stale_reservations(session, max_age_seconds=300)
+
+    assert released == 1
+    await session.refresh(key)
+    assert key.reserved_balance == 0
+    assert key.reserved_at is None
+
+
+@pytest.mark.asyncio
+async def test_release_stale_reservations_keeps_fresh(session: AsyncSession) -> None:
+    key = ApiKey(
+        hashed_key="freshkey",
+        balance=5_000,
+        reserved_balance=1_000,
+        reserved_at=int(time.time()),
+    )
+    session.add(key)
+    await session.commit()
+
+    released = await release_stale_reservations(session, max_age_seconds=300)
+
+    assert released == 0
+    await session.refresh(key)
+    assert key.reserved_balance == 1_000
+    assert key.reserved_at is not None
+
+
+@pytest.mark.asyncio
+async def test_release_stale_reservations_skips_null_reserved_at(session: AsyncSession) -> None:
+    # Reservations without a timestamp may belong to instances running older
+    # code (rolling deploy) — the background sweeper must not touch them.
+    key = ApiKey(
+        hashed_key="legacykey",
+        balance=5_000,
+        reserved_balance=1_000,
+        reserved_at=None,
+    )
+    session.add(key)
+    await session.commit()
+
+    released = await release_stale_reservations(session, max_age_seconds=300)
+
+    assert released == 0
+    await session.refresh(key)
+    assert key.reserved_balance == 1_000
+
+
+@pytest.mark.asyncio
+async def test_reset_all_reserved_balances_clears_reserved_at(session: AsyncSession) -> None:
+    key = ApiKey(
+        hashed_key="resetkey",
+        balance=5_000,
+        reserved_balance=1_000,
+        reserved_at=int(time.time()),
+    )
+    session.add(key)
+    await session.commit()
+
+    await reset_all_reserved_balances(session)
+
+    await session.refresh(key)
+    assert key.reserved_balance == 0
+    assert key.reserved_at is None
+
+
+# ---------------------------------------------------------------------------
+# Refund endpoint self-healing
+# ---------------------------------------------------------------------------
+
+
+def _refund_patches(refund_token: str = "cashuArefund"):  # type: ignore[no-untyped-def]
+    return (
+        patch("routstr.balance.send_token", AsyncMock(return_value=refund_token)),
+        patch("routstr.balance.store_cashu_transaction", AsyncMock()),
+        patch("routstr.balance._refund_cache_get", AsyncMock(return_value=None)),
+        patch("routstr.balance._refund_cache_set", AsyncMock()),
+    )
+
+
+async def _add_key(session: AsyncSession, **kwargs) -> ApiKey:  # type: ignore[no-untyped-def]
+    key = ApiKey(refund_currency="sat", **kwargs)
+    session.add(key)
+    await session.commit()
+    return key
+
+
+@pytest.mark.asyncio
+async def test_refund_self_heals_stale_reservation(session: AsyncSession) -> None:
+    key = await _add_key(
+        session,
+        hashed_key="stalerefund",
+        balance=5_000,
+        reserved_balance=2_000,
+        reserved_at=int(time.time()) - 10_000,
+    )
+
+    p1, p2, p3, p4 = _refund_patches()
+    with p1, p2, p3, p4:
+        result = await refund_wallet_endpoint(
+            authorization="Bearer sk-stalerefund",
+            x_cashu=None,
+            session=session,
+        )
+
+    assert isinstance(result, dict)
+    assert result["token"] == "cashuArefund"
+    # Full balance refunded (5000 msats -> 5 sats), reservation healed
+    assert result["sats"] == "5"
+    await session.refresh(key)
+    assert key.balance == 0
+    assert key.reserved_balance == 0
+    assert key.reserved_at is None
+
+
+@pytest.mark.asyncio
+async def test_refund_self_heals_legacy_null_reserved_at(session: AsyncSession) -> None:
+    # Keys stuck from before reserved_at existed must be refundable.
+    key = await _add_key(
+        session,
+        hashed_key="legacyrefund",
+        balance=5_000,
+        reserved_balance=2_000,
+        reserved_at=None,
+    )
+
+    p1, p2, p3, p4 = _refund_patches()
+    with p1, p2, p3, p4:
+        result = await refund_wallet_endpoint(
+            authorization="Bearer sk-legacyrefund",
+            x_cashu=None,
+            session=session,
+        )
+
+    assert isinstance(result, dict)
+    assert result["token"] == "cashuArefund"
+    await session.refresh(key)
+    assert key.balance == 0
+    assert key.reserved_balance == 0
+
+
+@pytest.mark.asyncio
+async def test_refund_rejects_recent_reservation(session: AsyncSession) -> None:
+    from fastapi import HTTPException
+
+    await _add_key(
+        session,
+        hashed_key="activerefund",
+        balance=5_000,
+        reserved_balance=2_000,
+        reserved_at=int(time.time()),
+    )
+
+    p1, p2, p3, p4 = _refund_patches()
+    with p1, p2, p3, p4:
+        with pytest.raises(HTTPException) as exc_info:
+            await refund_wallet_endpoint(
+                authorization="Bearer sk-activerefund",
+                x_cashu=None,
+                session=session,
+            )
+
+    assert exc_info.value.status_code == 400
+    assert "ongoing requests" in exc_info.value.detail
+
+
+@pytest.mark.asyncio
+async def test_refund_without_reservation_still_works(session: AsyncSession) -> None:
+    key = await _add_key(
+        session,
+        hashed_key="plainrefund",
+        balance=5_000,
+        reserved_balance=0,
+    )
+
+    p1, p2, p3, p4 = _refund_patches()
+    with p1, p2, p3, p4:
+        result = await refund_wallet_endpoint(
+            authorization="Bearer sk-plainrefund",
+            x_cashu=None,
+            session=session,
+        )
+
+    assert isinstance(result, dict)
+    assert result["token"] == "cashuArefund"
+    await session.refresh(key)
+    assert key.balance == 0
+
+
+# ---------------------------------------------------------------------------
+# Proxy reverts reservation on client disconnect
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_proxy_reverts_reservation_on_client_disconnect() -> None:
+    from routstr import proxy as proxy_module
+
+    key = ApiKey(hashed_key="cancelkey", balance=10_000)
+
+    request = MagicMock()
+    request.method = "POST"
+    request.headers = {"authorization": "Bearer sk-cancelkey"}
+    request.body = AsyncMock(return_value=b'{"model": "test-model"}')
+
+    upstream = MagicMock()
+    upstream.provider_type = "test"
+    upstream.prepare_headers = MagicMock(side_effect=lambda h: h)
+    upstream.forward_request = AsyncMock(side_effect=asyncio.CancelledError())
+
+    session = MagicMock()
+    revert_mock = AsyncMock(return_value=True)
+
+    with (
+        patch.object(proxy_module, "get_model_instance", return_value=MagicMock()),
+        patch.object(proxy_module, "get_provider_for_model", return_value=[upstream]),
+        patch.object(
+            proxy_module, "get_max_cost_for_model", AsyncMock(return_value=1_000)
+        ),
+        patch.object(
+            proxy_module,
+            "calculate_discounted_max_cost",
+            AsyncMock(return_value=1_000),
+        ),
+        patch.object(proxy_module, "check_token_balance", MagicMock()),
+        patch.object(
+            proxy_module, "get_bearer_token_key", AsyncMock(return_value=key)
+        ),
+        patch.object(proxy_module, "pay_for_request", AsyncMock(return_value=1_000)),
+        patch.object(proxy_module, "revert_pay_for_request", revert_mock),
+    ):
+        with pytest.raises(asyncio.CancelledError):
+            await proxy_module.proxy(request, "v1/chat/completions", session=session)
+
+    revert_mock.assert_awaited_once_with(key, session, 1_000)

tests/unit/test_streaming_sse_providers.py

@@ -337,3 +337,75 @@ async def test_multiline_non_json_data_each_line_prefixed() -> None:
             continue
         assert line.startswith(b"data: "), f"bare line leaked to client: {line!r}"
     assert b"data: line one" in blob and b"data: line two" in blob
+
+
+@pytest.mark.asyncio
+async def test_crlf_delimiter_split_across_chunk_boundary() -> None:
+    """CRLF event delimiter straddling two TCP reads must not merge events.
+
+    Regression: a per-chunk ``replace(b"\\r\\n", b"\\n")`` left a stray ``\\r``
+    when a ``\\r\\n`` of the ``\\r\\n\\r\\n`` delimiter landed at the very end of
+    one ``aiter_bytes`` chunk and the matching ``\\n`` opened the next. The
+    ``\\n\\n`` split then missed the boundary, glued two events into one frame
+    with two ``data:`` lines, and the client's ``JSON.parse`` threw on the
+    concatenated payload (the "unexpected token"/"Extra data" crash).
+    """
+    e1 = b'data: {"id":"x","choices":[{"delta":{"content":"a"}}]}'
+    e2 = b'data: {"id":"x","choices":[{"delta":{"content":"b"}}]}'
+    chunks = [
+        e1 + b"\r\n\r",  # delimiter cut mid-CRLF
+        b"\n" + e2 + b"\r\n\r\n",
+        b"data: [DONE]\r\n\r\n",
+    ]
+    out = await _drive(chunks)
+
+    # Client-accurate check: a real SSE client concatenates all ``data:`` lines
+    # *within one event* (events are ``\n\n``-delimited) before parsing. A
+    # merged frame would surface here as two objects glued into one payload,
+    # which ``_assert_clean`` (per-line) would miss.
+    blob = b"".join(out)
+    contents: list[str] = []
+    for event in blob.split(b"\n\n"):
+        datas = [
+            ln[len(b"data: ") :]
+            for ln in event.split(b"\n")
+            if ln.startswith(b"data: ")
+        ]
+        if not datas:
+            continue
+        payload = b"".join(datas)
+        if payload.strip() == b"[DONE]":
+            continue
+        obj = json.loads(payload)  # raises if two events were merged into one
+        for c in obj.get("choices", []):
+            if "delta" in c:
+                contents.append(c["delta"]["content"])
+    assert contents == ["a", "b"]
+
+
+@pytest.mark.asyncio
+async def test_truncated_json_tail_on_connection_close() -> None:
+    """A stream that drops mid-event must not emit the partial JSON downstream.
+
+    Regression: the end-of-stream flush ran ``_process_event`` on the leftover
+    buffer unconditionally. When the upstream connection closed mid-event the
+    leftover was incomplete JSON, which fell through to the raw-forward path and
+    handed the client a ``data: {partial`` frame -> ``Unterminated string`` parse
+    error. The truncated tail must be dropped instead.
+    """
+    chunks = [
+        b'data: {"id":"x","choices":[{"delta":{"content":"ok"}}]}\n\n',
+        b'data: {"id":"x","choices":[{"delta":{"con',  # connection dies here
+    ]
+    out = await _drive(chunks)
+    objs = _assert_clean(out)  # raises if the partial tail leaked as a data frame
+    contents = [
+        c["delta"]["content"]
+        for o in objs
+        for c in o.get("choices", [])
+        if "delta" in c
+    ]
+    # The one complete chunk is delivered; the truncated fragment is dropped
+    # entirely (no second delta), and _assert_clean above guarantees nothing
+    # non-JSON ever reached the client.
+    assert contents == ["ok"]

tests/unit/test_upstream_rate_limit.py

@@ -0,0 +1,396 @@
+"""Tests for upstream rate-limit detection, classification, and org-ID redaction.
+
+Covers issue #555: upstream OpenAI-compatible providers return rate-limit
+errors that embed a sensitive organization ID. The proxy must classify these
+distinctly (``UPSTREAM_RATE_LIMIT``), preserve useful debugging fields, and
+never emit a raw ``org-*`` identifier in logs, errors, or returned bodies.
+"""
+
+from __future__ import annotations
+
+import json
+from typing import Any
+from unittest.mock import AsyncMock, MagicMock, Mock, patch
+
+import httpx
+import pytest
+
+from routstr.core.redaction import redact_org_ids
+from routstr.upstream.base import BaseUpstreamProvider
+from routstr.upstream.rate_limit import (
+    UPSTREAM_RATE_LIMIT,
+    RateLimitInfo,
+    classify_rate_limit,
+)
+
+# The exact scenario from the issue, with a realistic (fake) org identifier.
+RAW_ORG_ID = "org-abc123XYZ456def"
+RATE_LIMIT_MESSAGE = (
+    f"Rate limit reached for gpt-5.5-2026-04-23 (for limit gpt-5.5) in "
+    f"organization {RAW_ORG_ID} on tokens per min (TPM): Limit 180000000, "
+    f"Used 180000000, Requested 8929. Please try again in 2ms. Visit "
+    f"https://platform.openai.com/account/rate-limits to learn more."
+)
+
+
+def _make_request(request_id: str = "req-123") -> Mock:
+    request = Mock(spec=["method", "state"])
+    request.method = "POST"
+    request.state = Mock()
+    request.state.request_id = request_id
+    return request
+
+
+def _make_upstream_response(
+    *,
+    body: bytes,
+    status_code: int = 429,
+    content_type: str | None = "application/json",
+    extra_headers: dict[str, str] | None = None,
+) -> httpx.Response:
+    headers: dict[str, str] = {}
+    if content_type is not None:
+        headers["content-type"] = content_type
+    if extra_headers:
+        headers.update(extra_headers)
+    return httpx.Response(status_code=status_code, headers=headers, content=body)
+
+
+@pytest.fixture
+def provider() -> BaseUpstreamProvider:
+    return BaseUpstreamProvider(
+        base_url="https://privateprovider.xyz", api_key="k", provider_fee=1.0
+    )
+
+
+# --------------------------------------------------------------------------- #
+# Redaction
+# --------------------------------------------------------------------------- #
+
+
+def test_redact_org_ids_replaces_identifier() -> None:
+    assert RAW_ORG_ID not in redact_org_ids(RATE_LIMIT_MESSAGE)
+    assert "org-[REDACTED]" in redact_org_ids(RATE_LIMIT_MESSAGE)
+
+
+def test_redact_org_ids_is_idempotent() -> None:
+    once = redact_org_ids(RATE_LIMIT_MESSAGE)
+    assert redact_org_ids(once) == once
+
+
+def test_redact_org_ids_leaves_unrelated_text() -> None:
+    assert redact_org_ids("organize the org-chart") == "organize the org-chart"
+    assert redact_org_ids("") == ""
+
+
+# --------------------------------------------------------------------------- #
+# Classification
+# --------------------------------------------------------------------------- #
+
+
+def test_classify_exact_scenario() -> None:
+    info = classify_rate_limit(429, RATE_LIMIT_MESSAGE)
+    assert isinstance(info, RateLimitInfo)
+    assert info.code == UPSTREAM_RATE_LIMIT
+    assert info.model == "gpt-5.5-2026-04-23"
+    assert info.limit_name == "gpt-5.5"
+    assert info.metric == "tokens per min (TPM)"
+    assert info.limit == 180000000
+    assert info.used == 180000000
+    assert info.requested == 8929
+    assert info.retry_after_seconds == pytest.approx(0.002)
+    # Redaction-safe: no raw org id survives into the structured view.
+    assert RAW_ORG_ID not in info.message
+    assert RAW_ORG_ID not in json.dumps(info.as_details())
+
+
+def test_classify_by_status_code_without_marker() -> None:
+    info = classify_rate_limit(429, "slow down")
+    assert info is not None
+    assert info.code == UPSTREAM_RATE_LIMIT
+
+
+def test_classify_by_message_marker_without_429() -> None:
+    info = classify_rate_limit(400, "rate_limit_exceeded for this key")
+    assert info is not None
+
+
+def test_retry_after_header_takes_precedence() -> None:
+    info = classify_rate_limit(429, RATE_LIMIT_MESSAGE, {"Retry-After": "12"})
+    assert info is not None
+    assert info.retry_after_seconds == pytest.approx(12.0)
+
+
+def test_non_rate_limit_error_is_not_classified() -> None:
+    assert classify_rate_limit(400, "invalid request: missing field 'model'") is None
+    assert classify_rate_limit(500, "internal server error") is None
+
+
+# --------------------------------------------------------------------------- #
+# forward_upstream_error_response integration
+# --------------------------------------------------------------------------- #
+
+
+@pytest.mark.asyncio
+async def test_json_rate_limit_body_is_redacted_and_forwarded(
+    provider: BaseUpstreamProvider,
+) -> None:
+    body = json.dumps(
+        {"error": {"message": RATE_LIMIT_MESSAGE, "type": "rate_limit_exceeded"}}
+    ).encode()
+    upstream = _make_upstream_response(body=body, status_code=429)
+
+    response = await provider.forward_upstream_error_response(
+        _make_request(), "v1/chat/completions", upstream
+    )
+
+    assert response.status_code == 429
+    raw = bytes(response.body).decode()
+    # No raw organization id may survive in the forwarded body.
+    assert RAW_ORG_ID not in raw
+    assert "org-[REDACTED]" in raw
+    # Body remains valid JSON; the original type is preserved while a stable
+    # rate-limit code is injected so callers can switch on it.
+    payload: dict[str, Any] = json.loads(raw)
+    assert payload["error"]["type"] == "rate_limit_exceeded"
+    assert payload["error"]["code"] == UPSTREAM_RATE_LIMIT
+    assert payload["error"]["details"]["model"] == "gpt-5.5-2026-04-23"
+    # A retry hint extracted from the message is surfaced as a header.
+    assert "retry-after" in {k.lower() for k in response.headers}
+
+
+@pytest.mark.asyncio
+async def test_non_json_rate_limit_envelope_uses_stable_code(
+    provider: BaseUpstreamProvider,
+) -> None:
+    upstream = _make_upstream_response(
+        body=RATE_LIMIT_MESSAGE.encode(),
+        status_code=429,
+        content_type="text/plain",
+    )
+
+    response = await provider.forward_upstream_error_response(
+        _make_request(), "v1/chat/completions", upstream
+    )
+
+    payload: dict[str, Any] = json.loads(bytes(response.body))
+    assert payload["error"]["code"] == UPSTREAM_RATE_LIMIT
+    assert payload["error"]["details"]["model"] == "gpt-5.5-2026-04-23"
+    serialized = json.dumps(payload)
+    assert RAW_ORG_ID not in serialized
+    assert "org-[REDACTED]" in serialized
+
+
+@pytest.mark.asyncio
+async def test_non_rate_limit_json_error_unchanged(
+    provider: BaseUpstreamProvider,
+) -> None:
+    body = json.dumps(
+        {"error": {"message": "missing field 'model'", "type": "invalid_request"}}
+    ).encode()
+    upstream = _make_upstream_response(body=body, status_code=400)
+
+    response = await provider.forward_upstream_error_response(
+        _make_request(), "v1/chat/completions", upstream
+    )
+
+    assert response.status_code == 400
+    payload: dict[str, Any] = json.loads(bytes(response.body))
+    assert payload["error"]["type"] == "invalid_request"
+    assert "retry-after" not in {k.lower() for k in response.headers}
+
+
+# --------------------------------------------------------------------------- #
+# UpstreamError -> proxy response (preserves code/details/status)
+# --------------------------------------------------------------------------- #
+
+
+def test_create_upstream_error_response_preserves_structure() -> None:
+    from routstr.core.exceptions import UpstreamError
+    from routstr.payment.helpers import create_upstream_error_response
+
+    info = classify_rate_limit(429, RATE_LIMIT_MESSAGE)
+    assert info is not None
+    err = UpstreamError(
+        f"Upstream error via litellm: {RATE_LIMIT_MESSAGE}",
+        status_code=429,
+        code=info.code,
+        details=info.as_details(),
+    )
+
+    response = create_upstream_error_response(err, _make_request())
+
+    # Original upstream status is preserved (not flattened to 502).
+    assert response.status_code == 429
+    payload: dict[str, Any] = json.loads(bytes(response.body))
+    assert payload["error"]["type"] == "upstream_error"
+    assert payload["error"]["code"] == UPSTREAM_RATE_LIMIT
+    assert payload["error"]["details"]["requested"] == 8929
+    serialized = json.dumps(payload)
+    assert RAW_ORG_ID not in serialized
+    assert "org-[REDACTED]" in serialized
+
+
+def test_generic_upstream_error_still_defaults_to_502() -> None:
+    from routstr.core.exceptions import UpstreamError
+    from routstr.payment.helpers import create_upstream_error_response
+
+    err = UpstreamError("connection refused")  # status_code defaults to 502
+
+    response = create_upstream_error_response(err, _make_request())
+
+    assert response.status_code == 502
+    payload: dict[str, Any] = json.loads(bytes(response.body))
+    assert payload["error"]["type"] == "upstream_error"
+    assert payload["error"]["code"] == 502
+    assert "details" not in payload["error"]
+
+
+# --------------------------------------------------------------------------- #
+# Structured log-extra redaction
+# --------------------------------------------------------------------------- #
+
+
+def test_security_filter_redacts_org_id_in_extra() -> None:
+    import logging
+
+    from routstr.core.logging import SecurityFilter
+
+    record = logging.LogRecord(
+        name="test",
+        level=logging.ERROR,
+        pathname=__file__,
+        lineno=1,
+        msg="upstream failed",
+        args=(),
+        exc_info=None,
+    )
+    # Simulate an ``extra={"body_preview": ...}`` field carrying an org id.
+    setattr(record, "body_preview", RATE_LIMIT_MESSAGE)
+
+    assert SecurityFilter().filter(record) is True
+    redacted: str = getattr(record, "body_preview")
+    assert RAW_ORG_ID not in redacted
+    assert "org-[REDACTED]" in redacted
+
+
+def test_security_filter_redacts_org_id_in_nested_extra() -> None:
+    import logging
+
+    from routstr.core.logging import SecurityFilter
+
+    record = logging.LogRecord(
+        name="test",
+        level=logging.ERROR,
+        pathname=__file__,
+        lineno=1,
+        msg="upstream failed",
+        args=(),
+        exc_info=None,
+    )
+    # Nested structures: dict containing a list containing the org id.
+    setattr(record, "body", {"error": {"messages": [RATE_LIMIT_MESSAGE]}})
+
+    assert SecurityFilter().filter(record) is True
+    serialized = json.dumps(getattr(record, "body"))
+    assert RAW_ORG_ID not in serialized
+    assert "org-[REDACTED]" in serialized
+
+
+# --------------------------------------------------------------------------- #
+# 5xx-wrapped rate limit through forward_upstream_error_response
+# --------------------------------------------------------------------------- #
+
+
+@pytest.mark.asyncio
+async def test_5xx_wrapped_rate_limit_is_classified(
+    provider: BaseUpstreamProvider,
+) -> None:
+    # Some providers wrap a rate-limit in a 5xx envelope; classification must
+    # key off the message marker, not only the 429 status.
+    body = json.dumps({"error": {"message": RATE_LIMIT_MESSAGE}}).encode()
+    upstream = _make_upstream_response(body=body, status_code=500)
+
+    response = await provider.forward_upstream_error_response(
+        _make_request(), "v1/chat/completions", upstream
+    )
+
+    assert response.status_code == 500
+    payload: dict[str, Any] = json.loads(bytes(response.body))
+    assert payload["error"]["code"] == UPSTREAM_RATE_LIMIT
+    serialized = json.dumps(payload)
+    assert RAW_ORG_ID not in serialized
+    assert "org-[REDACTED]" in serialized
+
+
+# --------------------------------------------------------------------------- #
+# Real proxy loop: structured error surfaced + reservation reverted once
+# --------------------------------------------------------------------------- #
+
+
+@pytest.mark.asyncio
+async def test_proxy_loop_surfaces_rate_limit_and_reverts_once() -> None:
+    from routstr import proxy as proxy_module
+    from routstr.core.db import ApiKey
+    from routstr.core.exceptions import UpstreamError
+
+    info = classify_rate_limit(429, RATE_LIMIT_MESSAGE)
+    assert info is not None
+
+    key = ApiKey(hashed_key="rlkey", balance=10_000)
+
+    request = MagicMock()
+    request.method = "POST"
+    request.headers = {"authorization": "Bearer sk-rlkey"}
+    request.body = AsyncMock(return_value=b'{"model": "test-model"}')
+    request.state = MagicMock()
+    request.state.request_id = "req-rl"
+
+    upstream = MagicMock()
+    upstream.provider_type = "test"
+    upstream.prepare_headers = MagicMock(side_effect=lambda h: h)
+    upstream.forward_request = AsyncMock(
+        side_effect=UpstreamError(
+            f"Upstream error via litellm: {RATE_LIMIT_MESSAGE}",
+            status_code=429,
+            code=info.code,
+            details=info.as_details(),
+        )
+    )
+
+    session = MagicMock()
+    revert_mock = AsyncMock(return_value=True)
+
+    with (
+        patch.object(proxy_module, "get_model_instance", return_value=MagicMock()),
+        patch.object(proxy_module, "get_provider_for_model", return_value=[upstream]),
+        patch.object(
+            proxy_module, "get_max_cost_for_model", AsyncMock(return_value=1_000)
+        ),
+        patch.object(
+            proxy_module,
+            "calculate_discounted_max_cost",
+            AsyncMock(return_value=1_000),
+        ),
+        patch.object(proxy_module, "check_token_balance", MagicMock()),
+        patch.object(
+            proxy_module, "get_bearer_token_key", AsyncMock(return_value=key)
+        ),
+        patch.object(proxy_module, "pay_for_request", AsyncMock(return_value=1_000)),
+        patch.object(proxy_module, "revert_pay_for_request", revert_mock),
+    ):
+        response = await proxy_module.proxy(
+            request, "v1/chat/completions", session=session
+        )
+
+    # Original 429 status and the stable code/details survive to the client.
+    assert response.status_code == 429
+    payload: dict[str, Any] = json.loads(bytes(response.body))
+    assert payload["error"]["type"] == "upstream_error"
+    assert payload["error"]["code"] == UPSTREAM_RATE_LIMIT
+    assert payload["error"]["details"]["requested"] == 8929
+    serialized = json.dumps(payload)
+    assert RAW_ORG_ID not in serialized
+    assert "org-[REDACTED]" in serialized
+    # Single upstream failed -> reservation reverted exactly once (no double-charge).
+    revert_mock.assert_awaited_once_with(key, session, 1_000)

tests/unit/test_usage_normalization.py

@@ -0,0 +1,140 @@
+"""Tests for vendor-agnostic usage normalization.
+
+Specifies the seam that keeps vendor usage dialects out of generic billing
+code: a canonical ``NormalizedUsage`` shape produced by
+``routstr.payment.usage.normalize_usage`` (union parser for the known,
+non-colliding dialects). ``calculate_cost`` normalizes the response's usage
+object with this parser and needs no vendor knowledge of its own.
+"""
+
+import os
+
+os.environ.setdefault("UPSTREAM_BASE_URL", "http://test")
+os.environ.setdefault("UPSTREAM_API_KEY", "test")
+os.environ.setdefault("LIGHTNING_ADDRESS", "test@stm.to")
+
+import pytest
+
+from routstr.payment.usage import NormalizedUsage, normalize_usage
+
+# ============================================================================
+# The union parser: one canonical shape for all known dialects
+# ============================================================================
+
+
+@pytest.mark.parametrize(
+    "usage,expected",
+    [
+        # OpenAI: cached_tokens included in prompt_tokens → subtracted
+        (
+            {
+                "prompt_tokens": 2000,
+                "completion_tokens": 100,
+                "prompt_tokens_details": {"cached_tokens": 800},
+            },
+            NormalizedUsage(
+                input_tokens=1200,
+                output_tokens=100,
+                cache_read_tokens=800,
+                cache_write_tokens=0,
+            ),
+        ),
+        # DeepSeek: hit/miss fields, prompt_tokens = hit + miss → hit subtracted
+        (
+            {
+                "prompt_tokens": 10000,
+                "completion_tokens": 500,
+                "prompt_cache_hit_tokens": 9000,
+                "prompt_cache_miss_tokens": 1000,
+            },
+            NormalizedUsage(
+                input_tokens=1000,
+                output_tokens=500,
+                cache_read_tokens=9000,
+                cache_write_tokens=0,
+            ),
+        ),
+        # Anthropic: cache fields additive, input_tokens NOT reduced
+        (
+            {
+                "input_tokens": 300,
+                "output_tokens": 100,
+                "cache_read_input_tokens": 500,
+                "cache_creation_input_tokens": 2000,
+            },
+            NormalizedUsage(
+                input_tokens=300,
+                output_tokens=100,
+                cache_read_tokens=500,
+                cache_write_tokens=2000,
+            ),
+        ),
+        # Plain OpenAI without caching
+        (
+            {"prompt_tokens": 100, "completion_tokens": 50},
+            NormalizedUsage(input_tokens=100, output_tokens=50),
+        ),
+        # OpenRouter: cache writes nested as prompt_tokens_details.cache_write_tokens,
+        # both reads and writes included in prompt_tokens → both subtracted
+        (
+            {
+                "prompt_tokens": 10000,
+                "completion_tokens": 60,
+                "prompt_tokens_details": {
+                    "cached_tokens": 5000,
+                    "cache_write_tokens": 2000,
+                },
+            },
+            NormalizedUsage(
+                input_tokens=3000,
+                output_tokens=60,
+                cache_read_tokens=5000,
+                cache_write_tokens=2000,
+            ),
+        ),
+        # litellm-normalized Anthropic: prompt_tokens is the grand total and the
+        # write field is named cache_creation_tokens; top-level fields mirror it.
+        # prompt_tokens present → both subtracted (NOT additive like native).
+        (
+            {
+                "prompt_tokens": 10000,
+                "completion_tokens": 100,
+                "cache_read_input_tokens": 5000,
+                "cache_creation_input_tokens": 2000,
+                "prompt_tokens_details": {
+                    "cached_tokens": 5000,
+                    "cache_creation_tokens": 2000,
+                },
+            },
+            NormalizedUsage(
+                input_tokens=3000,
+                output_tokens=100,
+                cache_read_tokens=5000,
+                cache_write_tokens=2000,
+            ),
+        ),
+    ],
+)
+def test_normalize_usage_dialects(usage: dict, expected: NormalizedUsage) -> None:
+    """Each known vendor dialect maps onto the same canonical shape."""
+    assert normalize_usage(usage) == expected
+
+
+def test_normalize_usage_absent_usage() -> None:
+    """Missing/invalid usage yields None so callers can bill at max cost."""
+    assert normalize_usage(None) is None
+    assert normalize_usage("not a dict") is None  # type: ignore[arg-type]
+
+
+def test_normalize_usage_never_negative() -> None:
+    """Buggy upstreams reporting more cached than prompt tokens clamp to 0."""
+    result = normalize_usage(
+        {
+            "prompt_tokens": 100,
+            "completion_tokens": 50,
+            "prompt_cache_hit_tokens": 150,
+        }
+    )
+    assert result is not None
+    assert result.input_tokens == 0
+    assert result.cache_read_tokens == 150

ui/README.md

@@ -1,36 +1,44 @@
-This is a [Next.js](https://nextjs.org) project bootstrapped with [`create-next-app`](https://nextjs.org/docs/app/api-reference/cli/create-next-app).
+# Routstr node admin UI
 
-## Getting Started
+A [Next.js](https://nextjs.org) app (App Router, **static export**) that provides the
+admin dashboard for a `routstr-core` node: login, settings, providers, balances,
+transactions, usage, and logs.
 
-First, run the development server:
+There is no separate web server in production. `next build` produces a fully static
+export (`next.config.ts` sets `output: 'export'`), and the FastAPI backend serves it
+directly from `../ui_out/` (see `routstr/core/main.py`). So the UI and the API are
+served from the **same origin** in production.
 
-```bash
-npm run dev
-# or
-yarn dev
-# or
-pnpm dev
-# or
-bun dev
-```
+## Developing the UI (hot reload)
 
-Open [http://localhost:3000](http://localhost:3000) with your browser to see the result.
+The everyday loop runs two processes side by side — you do **not** rebuild the static
+export while developing:
 
-You can start editing the page by modifying `app/page.tsx`. The page auto-updates as you edit the file.
+1. Start the backend on `:8000` — from the repo root: `make docker-up` (or
+   `uvicorn routstr.core.main:app --reload`).
+2. Start the Next.js dev server on `:3000` — from the repo root: `make ui-dev`
+   (or `cd ui && pnpm dev`). Edits hot-reload instantly.
 
-This project uses [`next/font`](https://nextjs.org/docs/app/building-your-application/optimizing/fonts) to automatically optimize and load [Geist](https://vercel.com/font), a new font family for Vercel.
+Open http://localhost:3000. With no `NEXT_PUBLIC_API_URL` set, the UI falls back to
+`http://127.0.0.1:8000` in development (see `lib/api/services/configuration.ts`), so it
+talks to the local backend out of the box.
 
-## Learn More
+Because dev is cross-origin (`:3000` → `:8000`), it relies on the backend's CORS
+allowing the UI origin. The default `cors_origins` is `["*"]`; if you tighten CORS,
+keep `http://localhost:3000` allowed for development.
 
-To learn more about Next.js, take a look at the following resources:
+## Building the integrated/static UI (what production serves)
 
-- [Next.js Documentation](https://nextjs.org/docs) - learn about Next.js features and API.
-- [Learn Next.js](https://nextjs.org/learn) - an interactive Next.js tutorial.
+To produce the bundle that FastAPI serves from `../ui_out/`:
 
-You can check out [the Next.js GitHub repository](https://github.com/vercel/next.js) - your feedback and contributions are welcome!
+- `make ui-build` — builds with local Node/pnpm (`scripts/build-ui.sh`), then moves
+  `ui/out/*` to `../ui_out/`.
+- `make ui-build-docker` — same, but inside Docker (no local Node needed).
 
-## Deploy on Vercel
+`NEXT_PUBLIC_*` variables are read from the repo-root `.env` at build time and baked in.
+For a same-origin deployment leave `NEXT_PUBLIC_API_URL` empty (relative paths); the UI
+uses `window.location.origin` at runtime. After building, start the backend and open
+http://localhost:8000 — the dashboard is served at `/` and `/admin`.
 
-The easiest way to deploy your Next.js app is to use the [Vercel Platform](https://vercel.com/new?utm_medium=default-template&filter=next.js&utm_source=create-next-app&utm_campaign=create-next-app-readme) from the creators of Next.js.
-
-Check out our [Next.js deployment documentation](https://nextjs.org/docs/app/building-your-application/deploying) for more details.
+If `../ui_out/` does not exist, the backend logs a warning at startup and serves the API
+only (hitting a UI route returns a small JSON fallback instead of the dashboard).

ui/app/providers/page.tsx

@@ -297,16 +297,13 @@ export default function ProvidersPage() {
   };
 
   const toggleProviderExpansion = (providerId: number) => {
-    const newExpanded = new Set(expandedProviders);
-    if (newExpanded.has(providerId)) {
-      newExpanded.delete(providerId);
-    } else {
-      newExpanded.add(providerId);
-    }
-    setExpandedProviders(newExpanded);
-    if (!newExpanded.has(providerId)) {
+    if (expandedProviders.has(providerId)) {
+      setExpandedProviders(new Set());
       setViewingModels(null);
     } else {
+      // Accordion: only one provider open at a time so switching to another
+      // provider's models auto-collapses the previously expanded one.
+      setExpandedProviders(new Set([providerId]));
       setViewingModels(providerId);
     }
   };