diff --git a/routstr/algorithm.py b/routstr/algorithm.py
index cced61f7..6a896665 100644
--- a/routstr/algorithm.py
+++ b/routstr/algorithm.py
@@ -135,9 +135,21 @@ def create_model_mappings(
     Returns:
         Tuple of (model_instances, provider_map, unique_models)
     """
-    from .payment.models import _row_to_model
+    from .payment.models import _row_to_model, has_usable_pricing
     from .upstream.helpers import resolve_model_alias
 
+    def _unusable_price(model: "Model") -> bool:
+        """A candidate may only route on rates a request can be billed against.
+
+        Mirrors the served-catalog backstop in ``list_models``: a negative or
+        non-finite rate is not a price, and the cost calculation cannot bill on
+        one, so every request on the model would be charged the full maximum
+        reservation instead. Applies to provider-discovered models as well as
+        persisted overrides — no override row need exist for a malformed price
+        to be built into the candidate map.
+        """
+        return not has_usable_pricing(model.pricing)
+
     candidates: dict[str, list[tuple["Model", "BaseUpstreamProvider"]]] = {}
     unique_models: dict[str, "Model"] = {}
     unique_model_keys: dict[str, str] = {}
@@ -225,12 +237,33 @@ def create_model_mappings(
             # Apply overrides only for this provider's model row.
             if model_key is not None and model_key in overrides_by_key:
                 override_row, provider_fee = overrides_by_key[model_key]
-                model_to_use = _row_to_model(
-                    override_row, apply_provider_fee=True, provider_fee=provider_fee
-                )
+                try:
+                    model_to_use = _row_to_model(
+                        override_row, apply_provider_fee=True, provider_fee=provider_fee
+                    )
+                except Exception as exc:
+                    # Stored pricing is JSON from whatever wrote the row, so
+                    # converting it can raise. Doing that inside this loop let
+                    # one such row unwind the whole map build: at boot the node
+                    # came up routing nothing, and on a later refresh the map it
+                    # already had went permanently stale. The sibling loop over
+                    # override-only rows already skips and logs such a row.
+                    logger.warning(
+                        "Skipping invalid model override while building model mappings",
+                        extra={
+                            "model_id": model.id,
+                            "upstream_provider_id": upstream_db_id,
+                            "error": str(exc),
+                            "error_type": type(exc).__name__,
+                        },
+                    )
+                    continue
             else:
                 model_to_use = model
 
+            if _unusable_price(model_to_use):
+                continue
+
             forwarded_model_id = get_effective_forwarded_model_id(model_to_use)
 
             # Get all aliases for this model
@@ -297,6 +330,8 @@ def create_model_mappings(
             continue
         if not model_to_use.enabled:
             continue
+        if _unusable_price(model_to_use):
+            continue
 
         forwarded_model_id = get_effective_forwarded_model_id(model_to_use)
 
diff --git a/routstr/core/admin.py b/routstr/core/admin.py
index 36a495a4..66e3a59a 100644
--- a/routstr/core/admin.py
+++ b/routstr/core/admin.py
@@ -5,12 +5,17 @@ from datetime import datetime, timezone
 from pathlib import Path
 
 from fastapi import APIRouter, Depends, HTTPException, Query, Request
-from pydantic import BaseModel, RootModel
+from pydantic import BaseModel, RootModel, field_validator
 from pydantic.v1 import ValidationError as PydanticValidationError
 from sqlmodel import select
 from sqlmodel.ext.asyncio.session import AsyncSession
 
-from ..payment.models import _row_to_model, list_models
+from ..payment.models import (
+    REQUIRED_PRICING_FIELDS,
+    _row_to_model,
+    list_models,
+)
+from ..payment.rates import BILLABLE_PRICING_FIELDS, coerce_rate
 from ..proxy import refresh_model_maps, reinitialize_upstreams
 from ..wallet import fetch_all_balances, send_token, token_mint_url
 from . import vault
@@ -29,6 +34,7 @@ from .db import (
 from .db import (
     store_cashu_transaction_with_retry as store_cashu_transaction,
 )
+from .exceptions import json_compliant
 from .log_manager import log_manager
 from .logging import get_logger
 from .provider_slugs import allocate_unique_provider_slug
@@ -519,6 +525,38 @@ class ModelCreate(BaseModel):
     enabled: bool = True
     forwarded_model_id: str | None = None
 
+    @field_validator("pricing")
+    @classmethod
+    def _validate_pricing(cls, value: dict[str, object]) -> dict[str, object]:
+        """Reject a rate that is malformed, non-finite, negative or not there.
+
+        A present-but-invalid rate would otherwise slip through: a non-numeric
+        string coerces to $0 on the read path (an unpriced-looking row), while a
+        negative or ``NaN``/``inf`` value is truthy and reads back as a real
+        price, so the model could be enabled and bill a nonsensical amount.
+        Surfacing a 422 reports the client bug as a client bug instead of
+        persisting it. Numeric strings (``"0.000005"``) stay valid, and so does
+        an omitted auxiliary rate — the stored JSON accepts both.
+        """
+        for field in BILLABLE_PRICING_FIELDS:
+            if field not in value:
+                # ``dict.get`` cannot tell this from an explicit ``null``, so
+                # both were skipped and a row that ``Pricing`` cannot parse was
+                # written — and then raised out of the response that reads it
+                # back, after the row had been committed.
+                if field in REQUIRED_PRICING_FIELDS:
+                    raise ValueError(f"{field} is required")
+                continue
+            # The shared coercion also absorbs the OverflowError an oversized
+            # integer raises, which pydantic does not convert into a validation
+            # error — unhandled it escaped as a 500 for a bad client value.
+            if coerce_rate(value[field]) is None:
+                raise ValueError(
+                    f"{field} must be a finite, non-negative number, "
+                    f"got {value[field]!r}"
+                )
+        return value
+
 
 def _normalize_forwarded_model_id(value: str | None) -> str | None:
     if value is None:
@@ -645,9 +683,13 @@ async def get_provider_model(provider_id: str, model_id: str) -> dict[str, objec
             raise HTTPException(
                 status_code=404, detail="Model not found for this provider"
             )
-        return _row_to_model(
-            row, apply_provider_fee=False, provider_fee=provider.provider_fee
-        ).dict()  # type: ignore
+        # Same duty as the listing this view is opened from: a stored rate that
+        # is not a usable number must be shown as it is, not encoded as `null`.
+        return json_compliant(  # type: ignore[return-value]
+            _row_to_model(
+                row, apply_provider_fee=False, provider_fee=provider.provider_fee
+            ).dict()
+        )
 
 
 @admin_router.delete(
@@ -1237,8 +1279,13 @@ async def get_provider_models(provider_id: str) -> dict[str, object]:
                 "provider_type": provider.provider_type,
                 "base_url": provider.base_url,
             },
-            "db_models": [m.dict() for m in db_models],
-            "remote_models": [m.dict() for m in filtered_remote_models],
+            # This listing includes disabled models, so it is the one view that
+            # still carries a row the served-catalog backstop holds back —
+            # including one whose stored rate is not a usable number. The
+            # encoder would report that rate as `null`, indistinguishable from a
+            # missing one; show the operator the value that needs fixing.
+            "db_models": [json_compliant(m.dict()) for m in db_models],
+            "remote_models": [json_compliant(m.dict()) for m in filtered_remote_models],
         }
 
 
diff --git a/routstr/core/exceptions.py b/routstr/core/exceptions.py
index a096455c..360b810d 100644
--- a/routstr/core/exceptions.py
+++ b/routstr/core/exceptions.py
@@ -1,4 +1,8 @@
+import math
+
 from fastapi import Request
+from fastapi.encoders import jsonable_encoder
+from fastapi.exceptions import RequestValidationError
 from fastapi.responses import JSONResponse
 
 from .logging import get_logger
@@ -71,6 +75,45 @@ async def http_exception_handler(request: Request, exc: Exception) -> JSONRespon
     return JSONResponse(status_code=status_code, content=content)
 
 
+def json_compliant(value: object) -> object:
+    """Render non-finite floats as text so a reply carrying them can serialize.
+
+    ``json`` parses the bare ``NaN``/``Infinity``/``-Infinity`` literals into
+    real floats, so a request body — and a stored row written from one — may
+    hold one anywhere. ``JSONResponse`` encodes with ``allow_nan=False`` and
+    raises on them, which would turn a reply that merely *quotes* the offending
+    value into a 500.
+    """
+    if isinstance(value, float) and not math.isfinite(value):
+        return repr(value)
+    if isinstance(value, dict):
+        return {key: json_compliant(item) for key, item in value.items()}
+    if isinstance(value, (list, tuple)):
+        return [json_compliant(item) for item in value]
+    return value
+
+
+async def validation_exception_handler(
+    request: Request, exc: Exception
+) -> JSONResponse:
+    """Answer a request-validation failure with a 422 that always serializes.
+
+    Pydantic echoes the rejected value back in each error's ``input`` field. A
+    non-finite float there breaks the encoder, so the 422 escapes as a 500 and
+    reports a client's bad rate as a server fault.
+    """
+    request_id = getattr(request.state, "request_id", "unknown")
+    errors = exc.errors() if isinstance(exc, RequestValidationError) else []
+
+    return JSONResponse(
+        status_code=422,
+        content={
+            "detail": json_compliant(jsonable_encoder(errors)),
+            "request_id": request_id,
+        },
+    )
+
+
 async def general_exception_handler(request: Request, exc: Exception) -> JSONResponse:
     """Handle general exceptions and include request ID in response."""
     request_id = getattr(request.state, "request_id", "unknown")
diff --git a/routstr/core/main.py b/routstr/core/main.py
index 979f5cdb..b89fa64d 100644
--- a/routstr/core/main.py
+++ b/routstr/core/main.py
@@ -4,6 +4,7 @@ from pathlib import Path
 from typing import AsyncGenerator
 
 from fastapi import FastAPI
+from fastapi.exceptions import RequestValidationError
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import FileResponse, RedirectResponse
 from fastapi.staticfiles import StaticFiles
@@ -33,7 +34,11 @@ from ..upstream.litellm_routing import configure_litellm
 from ..wallet import periodic_payout, periodic_refund_sweep, periodic_routstr_fee_payout
 from .admin import admin_router
 from .db import create_session, init_db, run_migrations
-from .exceptions import general_exception_handler, http_exception_handler
+from .exceptions import (
+    general_exception_handler,
+    http_exception_handler,
+    validation_exception_handler,
+)
 from .logging import get_logger, setup_logging
 from .middleware import LoggingMiddleware
 from .not_found import _NOT_FOUND_HTML, not_found_catch_all  # noqa: F401
@@ -289,6 +294,7 @@ app.add_middleware(LoggingMiddleware)
 
 # Add exception handlers
 app.add_exception_handler(HTTPException, http_exception_handler)  # type: ignore
+app.add_exception_handler(RequestValidationError, validation_exception_handler)
 app.add_exception_handler(Exception, general_exception_handler)
 
 
diff --git a/routstr/payment/cost_calculation.py b/routstr/payment/cost_calculation.py
index 86495728..a4ded317 100644
--- a/routstr/payment/cost_calculation.py
+++ b/routstr/payment/cost_calculation.py
@@ -6,6 +6,7 @@ from pydantic.v1 import BaseModel
 from ..core import get_logger
 from ..core.settings import settings
 from .price import sats_usd_price
+from .rates import coerce_rate, is_usable_rate
 from .usage import normalize_usage, parse_token_count
 
 if TYPE_CHECKING:
@@ -201,13 +202,14 @@ async def calculate_cost(
             cost_details = usage_data.get("cost_details", {})
             if not isinstance(cost_details, dict):
                 cost_details = {}
-            input_usd = _coerce_usd(
-                cost_details.get("input_cost")
-                or cost_details.get("upstream_inference_prompt_cost")
+            # Coerce each spelling before choosing between them: `inf` and `NaN`
+            # are truthy, so a malformed first field would otherwise win the
+            # fallback and the usable figure beside it would never be read.
+            input_usd = _coerce_usd(cost_details.get("input_cost")) or _coerce_usd(
+                cost_details.get("upstream_inference_prompt_cost")
             )
-            output_usd = _coerce_usd(
-                cost_details.get("output_cost")
-                or cost_details.get("upstream_inference_completions_cost")
+            output_usd = _coerce_usd(cost_details.get("output_cost")) or _coerce_usd(
+                cost_details.get("upstream_inference_completions_cost")
             )
             cache_pricing_rates: tuple[float, float, float, float] | None = None
             if cache_read_tokens > 0 or cache_creation_tokens > 0:
@@ -267,9 +269,14 @@ async def calculate_cost(
     else:
         input_rate, output_rate, cache_read_rate, cache_creation_rate = pricing_rates
 
-    if not (input_rate and output_rate):
+    # Truthiness is not the question: `NaN` and a negative rate are both truthy
+    # and sailed past this gate into the token math, while a rate of zero is a
+    # price — free — and reading it as a missing one charged the whole
+    # reservation for a request the model serves for nothing.
+    rates = (input_rate, output_rate, cache_read_rate, cache_creation_rate)
+    if not all(is_usable_rate(rate) for rate in rates):
         logger.warning(
-            "No token pricing configured — billing at flat MaxCostData. "
+            "No usable token pricing — billing at flat MaxCostData. "
             "Token counts %s in the upstream response but cannot be "
             "priced; the request will appear in dashboards with the "
             "raw counts and a fixed max-cost charge.",
@@ -279,6 +286,8 @@ async def calculate_cost(
                 "model": response_data.get("model", "unknown"),
                 "input_tokens": input_tokens,
                 "output_tokens": output_tokens,
+                "input_rate": input_rate,
+                "output_rate": output_rate,
             },
         )
         return MaxCostData(
@@ -313,15 +322,25 @@ async def calculate_cost(
 
 
 def _coerce_usd(value: object) -> float:
-    """Coerce a value to USD float, handling various formats safely."""
-    if value is None or isinstance(value, bool):
-        return 0.0
-    if not isinstance(value, (int, float, str)):
-        return 0.0
-    try:
-        return max(0.0, float(value))
-    except (TypeError, ValueError):
-        return 0.0
+    """Coerce an upstream-reported USD figure to a usable amount, else ``0.0``.
+
+    These values come straight off the upstream response, where ``json.loads``
+    accepts the bare ``NaN``/``Infinity`` literals and overflows ``1e999`` to
+    ``inf``. A non-finite figure is not a cost, and letting one through poisoned
+    the proportional split in ``_calculate_from_usd_cost`` (``inf / inf`` is
+    ``NaN``): the resulting exception was absorbed by the broad handler around
+    the USD path, so a request whose *total* cost was perfectly valid fell
+    through to token-estimated pricing and was billed a fraction of what the
+    upstream charged.
+
+    ``0.0`` means "no usable figure" to every caller, which is the same thing an
+    absent field means, so the caller's existing ``> 0`` checks handle it.
+    """
+    # A cost figure is coerced exactly like a rate; only the way an unusable one
+    # is reported differs. A negative is rejected here, where the previous
+    # `max(0.0, …)` clamped it.
+    amount = coerce_rate(value)
+    return amount if amount is not None else 0.0
 
 
 def _resolve_usd_cost(usage_data: dict, response_data: dict) -> float:
diff --git a/routstr/payment/models.py b/routstr/payment/models.py
index 3deedb5a..e7b160fb 100644
--- a/routstr/payment/models.py
+++ b/routstr/payment/models.py
@@ -12,6 +12,7 @@ from ..core.db import ModelRow, UpstreamProviderRow, get_session
 from ..core.logging import get_logger
 from ..core.settings import settings
 from .price import sats_usd_price
+from .rates import BILLABLE_PRICING_FIELDS, coerce_rate, is_usable_rate
 
 logger = get_logger(__name__)
 
@@ -58,6 +59,26 @@ class Pricing(BaseModel):
     max_cost: float = 0.0  # in sats not msats
 
 
+# The rates ``Pricing`` declares without a default, derived from the model so the
+# two cannot drift. A payload that omits one writes a row that will not parse.
+REQUIRED_PRICING_FIELDS = tuple(
+    name for name, field in Pricing.__fields__.items() if field.required
+)
+
+
+def has_usable_pricing(pricing: Pricing) -> bool:
+    """True if every billable rate is a number a request could be billed on.
+
+    Free is usable — a rate of zero is a real price. This asks only whether the
+    price is well-formed. One unusable rate disqualifies the whole price even
+    alongside a valid one, since a request can bill on the bad field: a positive
+    ``completion`` must not hide a negative ``prompt``.
+    """
+    return all(
+        is_usable_rate(getattr(pricing, field)) for field in BILLABLE_PRICING_FIELDS
+    )
+
+
 class TopProvider(BaseModel):
     context_length: int | None = None
     max_completion_tokens: int | None = None
@@ -144,18 +165,17 @@ def backfill_cache_pricing(model_id: str, pricing: Pricing) -> Pricing:
 
 
 def _has_valid_pricing(model: dict) -> bool:
-    """Check if model has valid pricing (not free, no negative values)."""
+    """Check if model has valid pricing (usable rates, and not free)."""
     pricing = model.get("pricing", {})
     if not pricing:
         return False
 
-    try:
-        prompt = float(pricing.get("prompt", 0))
-        completion = float(pricing.get("completion", 0))
-    except (ValueError, TypeError):
-        return False
-
-    if prompt < 0 or completion < 0:
+    # Coercion runs before the both-zero test below, which `NaN` would defeat
+    # on its own — and one entry the coercion chokes on must not unwind the
+    # whole fetch, which once cost the node an entire upstream catalog.
+    prompt = coerce_rate(pricing.get("prompt", 0))
+    completion = coerce_rate(pricing.get("completion", 0))
+    if prompt is None or completion is None:
         return False
 
     if prompt == 0 and completion == 0:
@@ -309,21 +329,57 @@ async def list_models(
     rows = (await session.exec(query)).all()  # type: ignore
     provider_result = await session.exec(select(UpstreamProviderRow))
     providers_by_id = {p.id: p for p in provider_result.all()}
-    return [
-        _row_to_model(
-            r,
-            apply_provider_fee=apply_fees,
-            provider_fee=providers_by_id[r.upstream_provider_id].provider_fee
-            if r.upstream_provider_id in providers_by_id
-            else 1.01,
-        )
-        for r in rows
-        if include_disabled
-        or (
+
+    models: list[Model] = []
+    for r in rows:
+        if not include_disabled and not (
             r.upstream_provider_id in providers_by_id
             and providers_by_id[r.upstream_provider_id].enabled
-        )
-    ]
+        ):
+            continue
+        try:
+            model = _row_to_model(
+                r,
+                apply_provider_fee=apply_fees,
+                provider_fee=providers_by_id[r.upstream_provider_id].provider_fee
+                if r.upstream_provider_id in providers_by_id
+                else 1.01,
+            )
+        except Exception as e:
+            # Stored pricing/architecture is JSON from whatever wrote the row, so
+            # a legacy import or foreign writer can leave a field that will not
+            # parse. Converting inside this loop meant one such row raised out of
+            # the whole listing and the node advertised nothing at all. Drop the
+            # row we cannot read — it is unservable either way — and keep serving
+            # the rest.
+            logger.warning(
+                "Skipping model row that could not be read",
+                extra={
+                    "model_id": r.id,
+                    "upstream_provider_id": r.upstream_provider_id,
+                    "error": str(e),
+                    "error_type": type(e).__name__,
+                },
+            )
+            continue
+        # Served-map backstop for legacy rows and writers that bypass the admin
+        # edge: a negative or non-finite rate is not a price. Serving one
+        # advertises a rate the cost calculation cannot bill on, so the request
+        # falls through to the flat maximum reservation — or, if the rate is
+        # negative, bills an amount settlement credits back to the caller.
+        # ``include_disabled`` is the operator's listing, which must keep showing
+        # the row so it can be repaired.
+        if not include_disabled and not has_usable_pricing(model.pricing):
+            logger.warning(
+                "Withholding model with an unusable stored rate from the catalog",
+                extra={
+                    "model_id": r.id,
+                    "upstream_provider_id": r.upstream_provider_id,
+                },
+            )
+            continue
+        models.append(model)
+    return models
 
 
 def _calculate_usd_max_costs(model: Model) -> tuple[float, float, float]:
diff --git a/routstr/payment/price.py b/routstr/payment/price.py
index ad614322..e63d6754 100644
--- a/routstr/payment/price.py
+++ b/routstr/payment/price.py
@@ -5,12 +5,37 @@ import httpx
 
 from ..core import get_logger
 from ..core.settings import settings
+from .rates import coerce_rate
 
 logger = get_logger(__name__)
 
 BTC_USD_PRICE: float | None = None
 SATS_USD_PRICE: float | None = None
 
+SATS_PER_BTC = 100_000_000
+
+
+def _parse_quote(raw: object, exchange: str) -> float | None:
+    """Coerce an exchange quote to a price, or ``None`` if it is not one.
+
+    Every quote passes through here because the aggregator takes the ``min()``
+    of what it collects: an unusable quote does not merely join the sample, it
+    *wins* it, and the result is the rate every model and every request on the
+    node is priced at. A quote is stricter than a billable rate — it must be
+    positive, and positive *after* the sats conversion the node prices in: a
+    subnormal quote survives every guard here and still underflows to a zero
+    sats price, which then divides by zero on every model's rate.
+    """
+    price = coerce_rate(raw)
+    if price is None or price <= 0 or price / SATS_PER_BTC <= 0:
+        logger.warning(
+            "Unusable price quote — ignoring this exchange",
+            extra={"exchange": exchange, "quote": repr(raw)},
+        )
+        return None
+
+    return price
+
 
 async def _kraken_btc_usd(client: httpx.AsyncClient) -> float | None:
     """Fetch BTC/USD price from Kraken API."""
@@ -18,10 +43,11 @@ async def _kraken_btc_usd(client: httpx.AsyncClient) -> float | None:
     try:
         response = await client.get(api)
         price_data = response.json()
-        price = float(price_data["result"]["XXBTZUSD"]["c"][0])
-
-        return price
-    except (httpx.RequestError, KeyError) as e:
+        return _parse_quote(price_data["result"]["XXBTZUSD"]["c"][0], "kraken")
+    except (httpx.RequestError, KeyError, IndexError, TypeError, ValueError) as e:
+        # A payload whose *shape* changed raises IndexError/TypeError, and a
+        # non-JSON body raises ValueError; unhandled, one exchange's bad day
+        # aborted the whole aggregation instead of dropping a single quote.
         logger.warning(
             "Kraken API error",
             extra={
@@ -39,10 +65,8 @@ async def _coinbase_btc_usd(client: httpx.AsyncClient) -> float | None:
     try:
         response = await client.get(api)
         price_data = response.json()
-        price = float(price_data["data"]["amount"])
-
-        return price
-    except (httpx.RequestError, KeyError) as e:
+        return _parse_quote(price_data["data"]["amount"], "coinbase")
+    except (httpx.RequestError, KeyError, IndexError, TypeError, ValueError) as e:
         logger.warning(
             "Coinbase API error",
             extra={
@@ -60,10 +84,8 @@ async def _binance_btc_usdt(client: httpx.AsyncClient) -> float | None:
     try:
         response = await client.get(api)
         price_data = response.json()
-        price = float(price_data["price"])
-
-        return price
-    except (httpx.RequestError, KeyError) as e:
+        return _parse_quote(price_data["price"], "binance")
+    except (httpx.RequestError, KeyError, IndexError, TypeError, ValueError) as e:
         logger.warning(
             "Binance API error",
             extra={
@@ -123,7 +145,7 @@ async def _update_prices() -> None:
         )
         return
     BTC_USD_PRICE = btc_price
-    SATS_USD_PRICE = btc_price / 100_000_000
+    SATS_USD_PRICE = btc_price / SATS_PER_BTC
 
 
 def btc_usd_price() -> float:
diff --git a/routstr/payment/rates.py b/routstr/payment/rates.py
new file mode 100644
index 00000000..998f3ca5
--- /dev/null
+++ b/routstr/payment/rates.py
@@ -0,0 +1,71 @@
+"""The one definition of a billable rate, with no dependencies of its own.
+
+A rate reaches the node from an upstream catalog, the LiteLLM cost map, an
+operator's admin edit, a legacy database row and the BTC/USD feed. Each of those
+readers needs the same two questions answered — is this value a rate at all, and
+is it a rate a request can be billed on — so both answers live here, in a module
+that imports nothing from the package. Every guard then shares one definition
+instead of drifting, and no caller needs a deferred import to reach it.
+"""
+
+import math
+
+# The rates a request can bill on. Derived fields (``max_*_cost``) are excluded
+# — they are computed carriers, not charged rates. One definition, shared by the
+# admin write edge and the served/routed guards, so they all cover the same set.
+BILLABLE_PRICING_FIELDS = (
+    "prompt",
+    "completion",
+    "request",
+    "image",
+    "web_search",
+    "internal_reasoning",
+    "input_cache_read",
+    "input_cache_write",
+)
+
+
+def is_usable_rate(rate: float) -> bool:
+    """True if a single billable rate is a number a request could be billed on.
+
+    The one definition of a usable rate, so every guard that asks the question
+    answers it identically. A rate qualifies only when it is finite and
+    non-negative; zero is usable (it means "free", which is a real price) but
+    ``NaN``, ``±inf`` and negatives are not prices at all.
+
+    Non-finite: ``inf > 0`` is True, so an infinite rate reads as chargeable and
+    would be served, routed and billed as ``inf``; ``NaN`` poisons every total it
+    enters and defeats ordinary comparisons, since ``NaN > 0``, ``NaN < 0`` and
+    ``NaN == 0`` are all False. Negative: a negative rate produces a negative
+    cost, which the settlement path subtracts from the balance — it pays the
+    caller to make requests. Both reach a stored row from upstream catalogs as
+    well as the admin edge (``json.loads`` accepts the bare ``NaN``/``Infinity``
+    literals and overflows ``1e999`` to ``inf``).
+
+    This is the rationale for every guard that calls it; the call sites say what
+    they do with the answer, not why the answer matters.
+    """
+    return math.isfinite(rate) and rate >= 0.0
+
+
+def coerce_rate(value: object) -> float | None:
+    """Coerce a value from outside the node to a usable rate, or ``None``.
+
+    The one coercion, shared by every reader of a rate the node did not compute
+    itself: an upstream catalog, the LiteLLM cost map, the exchange feed and the
+    admin write edge. Each of them was parsing for itself, and they disagreed —
+    which is how a boolean became a price on some paths and not others.
+
+    A boolean is rejected outright: it is a change of shape, not a rate, and
+    Python would make ``True`` a finite, positive ``1.0`` that passes every
+    numeric guard downstream — a dollar per token. A numeric string is accepted,
+    because feeds report prices as strings. An oversized integer raises
+    ``OverflowError`` rather than ``ValueError``, so that is caught too.
+    """
+    if isinstance(value, bool) or not isinstance(value, (int, float, str)):
+        return None
+    try:
+        rate = float(value)
+    except (TypeError, ValueError, OverflowError):
+        return None
+    return rate if is_usable_rate(rate) else None
diff --git a/routstr/upstream/pricing_resolver.py b/routstr/upstream/pricing_resolver.py
index 3d009fdc..8b58dddb 100644
--- a/routstr/upstream/pricing_resolver.py
+++ b/routstr/upstream/pricing_resolver.py
@@ -17,6 +17,8 @@ from __future__ import annotations
 
 from dataclasses import dataclass, field
 
+from ..payment.rates import coerce_rate
+
 
 @dataclass
 class ResolvedPricing:
@@ -65,11 +67,8 @@ def estimate_context_length(model_id: str) -> int:
 
 
 def _as_float(value: object) -> float | None:
-    """OpenRouter reports prices as strings; coerce, ``None`` if unparseable."""
-    try:
-        return float(value)  # type: ignore[arg-type]
-    except (TypeError, ValueError):
-        return None
+    """OpenRouter reports prices as strings; coerce, ``None`` if not a real rate."""
+    return coerce_rate(value)
 
 
 def _as_int(value: object) -> int | None:
@@ -78,23 +77,24 @@ def _as_int(value: object) -> int | None:
 
 
 def _from_litellm(model_id: str) -> ResolvedPricing | None:
-    # Lazy import so the resolver stays import-light and shares the exact
-    # lookup semantics used by cache-rate backfill.
+    # Lazy import so the resolver shares the exact lookup semantics used by
+    # cache-rate backfill without importing the models module at load time.
     from ..payment.models import litellm_cost_entry
 
     info = litellm_cost_entry(model_id)
     if info is None:
         return None
 
-    prompt = info.get("input_cost_per_token")
-    completion = info.get("output_cost_per_token")
-    if not isinstance(prompt, (int, float)) or not isinstance(completion, (int, float)):
+    prompt = coerce_rate(info.get("input_cost_per_token"))
+    completion = coerce_rate(info.get("output_cost_per_token"))
+    if prompt is None or completion is None:
         return None
     # A both-zero entry is litellm listing a model without a real price (free
     # moderation/rerank tiers do this) — treating 0/0 as resolved would serve
-    # the model for free. Reject it (and any negative) so the caller falls
-    # through, mirroring async_fetch_openrouter_models' _has_valid_pricing.
-    if prompt < 0 or completion < 0 or (prompt == 0 and completion == 0):
+    # the model for free. Reject it so the caller falls through, mirroring
+    # async_fetch_openrouter_models' _has_valid_pricing. Coercion runs first:
+    # `NaN` would defeat this guard on its own, every comparison being False.
+    if prompt == 0 and completion == 0:
         return None
 
     input_modalities = ["text"]
@@ -102,8 +102,8 @@ def _from_litellm(model_id: str) -> ResolvedPricing | None:
         input_modalities.append("image")
 
     return ResolvedPricing(
-        prompt=float(prompt),
-        completion=float(completion),
+        prompt=prompt,
+        completion=completion,
         # max_input_tokens is the context window; max_tokens is litellm's
         # completion cap (it tracks max_output_tokens for ~94% of models), so
         # it is never a context source. A missing window falls to the id-based
diff --git a/tests/integration/conftest.py b/tests/integration/conftest.py
index 7848e38c..f369182c 100644
--- a/tests/integration/conftest.py
+++ b/tests/integration/conftest.py
@@ -516,6 +516,10 @@ async def integration_app(
     # Copy all routes from the main app
     test_app.router = app.router
 
+    # ...and its exception handlers, so a request that fails here fails the way
+    # it would in production rather than escaping as a bare exception.
+    test_app.exception_handlers.update(app.exception_handlers)
+
     # Override the get_session dependency
     async def override_get_session() -> AsyncGenerator[AsyncSession, None]:
         yield integration_session
diff --git a/tests/integration/test_admin_pricing_rate_validation.py b/tests/integration/test_admin_pricing_rate_validation.py
new file mode 100644
index 00000000..2e9a45b9
--- /dev/null
+++ b/tests/integration/test_admin_pricing_rate_validation.py
@@ -0,0 +1,469 @@
+"""Admin write edge: a rate that is not a number never becomes a stored price.
+
+A billable rate is usable only when it is finite and non-negative. The admin
+model endpoints are an entry point for rates the node will later bill on, and
+they accept whatever a client sends: ``json`` parses the bare ``NaN``/
+``Infinity`` literals into real floats and overflows ``1e999`` to ``inf``, a
+non-numeric string coerced silently to ``$0``, and a negative rate is truthy so
+it read back as a chargeable price that bills a negative amount.
+
+These tests assert the edge answers a malformed rate with a 422 — a client bug
+reported as a client bug — rather than persisting it or failing as a 500, and
+that the operator can still open the listing that shows the row needing repair.
+"""
+
+from __future__ import annotations
+
+import json
+from datetime import datetime, timedelta, timezone
+
+import pytest
+from httpx import AsyncClient
+from sqlmodel.ext.asyncio.session import AsyncSession
+
+from routstr.core.admin import admin_sessions
+from routstr.core.db import ModelRow, UpstreamProviderRow
+from routstr.proxy import reinitialize_upstreams
+
+
+def _admin_headers() -> dict[str, str]:
+    token = "test-admin-rate-validation-token"
+    admin_sessions[token] = int(
+        (datetime.now(timezone.utc) + timedelta(minutes=5)).timestamp()
+    )
+    return {"Authorization": f"Bearer {token}"}
+
+
+def _pricing(**overrides: object) -> dict[str, object]:
+    pricing: dict[str, object] = {
+        "prompt": 1.4e-7,
+        "completion": 2.8e-7,
+        "request": 0.0,
+        "image": 0.0,
+        "web_search": 0.0,
+        "internal_reasoning": 0.0,
+        "input_cache_read": 0.0,
+        "input_cache_write": 0.0,
+    }
+    pricing.update(overrides)
+    return pricing
+
+
+def _payload(
+    provider_id: int,
+    *,
+    model_id: str = "rate-model",
+    pricing: dict[str, object] | None = None,
+) -> dict[str, object]:
+    return {
+        "id": model_id,
+        "name": "Rate Model",
+        "description": "d",
+        "created": 0,
+        "context_length": 128000,
+        "architecture": {
+            "modality": "text",
+            "input_modalities": ["text"],
+            "output_modalities": ["text"],
+            "tokenizer": "unknown",
+            "instruct_type": None,
+        },
+        "pricing": pricing if pricing is not None else _pricing(),
+        "per_request_limits": None,
+        "top_provider": None,
+        "upstream_provider_id": provider_id,
+        "canonical_slug": None,
+        "alias_ids": [],
+        "enabled": True,
+        "forwarded_model_id": model_id,
+    }
+
+
+async def _make_provider(session: AsyncSession) -> int:
+    provider = UpstreamProviderRow(
+        provider_type="generic",
+        base_url="https://rate-upstream.example/v1",
+        api_key="test-key",
+        provider_fee=1.0,
+    )
+    session.add(provider)
+    await session.commit()
+    await session.refresh(provider)
+    await reinitialize_upstreams()
+    assert provider.id is not None
+    return provider.id
+
+
+def _raw_model_body(provider_id: int, model_id: str, prompt_literal: str) -> str:
+    """A request body built as text, so it can carry a literal ``json`` accepts
+    but Python's own encoder would refuse to produce."""
+    return (
+        f'{{"id": "{model_id}", "name": "raw", "description": "d", "created": 0,'
+        ' "context_length": 8192, "architecture": {"modality": "text"},'
+        f' "pricing": {{"prompt": {prompt_literal}, "completion": 2.8e-7}},'
+        f' "upstream_provider_id": {provider_id}}}'
+    )
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_negative_price_is_rejected(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """A negative rate is not a valid price — accepting it would persist a row
+    that bills a negative amount, which settlement subtracts from the balance.
+    Being truthy, it also reads back as a chargeable price. Reject at the edge
+    rather than silently storing it."""
+    provider_id = await _make_provider(integration_session)
+
+    resp = await integration_client.post(
+        f"/admin/api/upstream-providers/{provider_id}/models",
+        headers=_admin_headers(),
+        json=_payload(provider_id, model_id="neg-price", pricing=_pricing(prompt=-1.0)),
+    )
+
+    assert resp.status_code == 422
+    assert await integration_session.get(ModelRow, ("neg-price", provider_id)) is None
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_malformed_price_string_is_rejected(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """A present non-numeric rate is a client bug: it coerces to ``$0`` on the
+    read path, producing an unpriced-looking row indistinguishable from a
+    deliberate free price. Surface it as a 422 instead of accepting it."""
+    provider_id = await _make_provider(integration_session)
+
+    resp = await integration_client.post(
+        f"/admin/api/upstream-providers/{provider_id}/models",
+        headers=_admin_headers(),
+        json=_payload(
+            provider_id, model_id="bad-price", pricing=_pricing(prompt="oops")
+        ),
+    )
+
+    assert resp.status_code == 422
+    assert await integration_session.get(ModelRow, ("bad-price", provider_id)) is None
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_boolean_price_is_rejected(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """A JSON ``true`` coerces to a finite, positive ``1.0`` — a dollar per
+    token — so it passes every numeric guard. The write edge asks the same
+    coercion the catalog readers do, and answers a 422."""
+    provider_id = await _make_provider(integration_session)
+
+    resp = await integration_client.post(
+        f"/admin/api/upstream-providers/{provider_id}/models",
+        headers=_admin_headers(),
+        json=_payload(
+            provider_id, model_id="bool-price", pricing=_pricing(prompt=True)
+        ),
+    )
+
+    assert resp.status_code == 422
+    assert await integration_session.get(ModelRow, ("bool-price", provider_id)) is None
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    ("model_id", "pricing"),
+    [
+        ("null-prompt", _pricing(prompt=None)),
+        ("null-aux-rate", _pricing(image=None)),
+        ("no-prompt", {k: v for k, v in _pricing().items() if k != "prompt"}),
+    ],
+    ids=["null-required", "null-auxiliary", "absent-required"],
+)
+async def test_a_rate_that_is_not_there_is_rejected(
+    model_id: str,
+    pricing: dict[str, object],
+    integration_client: AsyncClient,
+    integration_session: AsyncSession,
+) -> None:
+    """A rate given as ``null``, or a required rate left out, is not a price.
+
+    ``dict.get`` cannot tell the two apart and skipped both, so a row
+    ``Pricing`` cannot parse was committed and the response that reads it back
+    raised.
+    """
+    provider_id = await _make_provider(integration_session)
+
+    resp = await integration_client.post(
+        f"/admin/api/upstream-providers/{provider_id}/models",
+        headers=_admin_headers(),
+        json=_payload(provider_id, model_id=model_id, pricing=pricing),
+    )
+
+    assert resp.status_code == 422
+    assert await integration_session.get(ModelRow, (model_id, provider_id)) is None
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_an_absent_auxiliary_rate_is_still_accepted(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """Only ``prompt`` and ``completion`` are required; the rest carry defaults,
+    and a payload that omits them must still be accepted."""
+    provider_id = await _make_provider(integration_session)
+
+    resp = await integration_client.post(
+        f"/admin/api/upstream-providers/{provider_id}/models",
+        headers=_admin_headers(),
+        json=_payload(
+            provider_id,
+            model_id="lean-price",
+            pricing={"prompt": 1.4e-7, "completion": 2.8e-7},
+        ),
+    )
+
+    assert resp.status_code == 200
+    assert await integration_session.get(ModelRow, ("lean-price", provider_id))
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_numeric_string_price_is_still_accepted(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """The stored pricing JSON has always accepted numeric strings, and the UI
+    round-trips rates through text fields. Rejecting a *malformed* rate must not
+    also reject a well-formed one that arrives spelled as a string."""
+    provider_id = await _make_provider(integration_session)
+
+    resp = await integration_client.post(
+        f"/admin/api/upstream-providers/{provider_id}/models",
+        headers=_admin_headers(),
+        json=_payload(
+            provider_id, model_id="string-price", pricing=_pricing(prompt="0.000005")
+        ),
+    )
+
+    assert resp.status_code == 200
+    row = await integration_session.get(ModelRow, ("string-price", provider_id))
+    assert row is not None
+    assert json.loads(row.pricing)["prompt"] == "0.000005"
+
+
+def test_non_finite_price_is_rejected_by_the_write_model() -> None:
+    """``NaN``/``±inf`` are not billable rates: the carrier every write endpoint
+    shares must reject them before they can be persisted and read back as a
+    chargeable price."""
+    from pydantic import ValidationError
+
+    from routstr.core.admin import ModelCreate
+
+    for bad in (float("nan"), float("inf"), float("-inf")):
+        with pytest.raises(ValidationError):
+            ModelCreate.model_validate(
+                _payload(1, model_id="nonfinite", pricing=_pricing(prompt=bad))
+            )
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_oversized_integer_price_is_rejected(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """A JSON integer too large for a float is a client bug, not a server fault.
+
+    ``float()`` raises ``OverflowError`` for it, and pydantic converts only
+    ``ValueError``/``AssertionError`` into validation errors, so it escaped the
+    edge as a 500. It must be answered with the same 422 as every other
+    unusable rate.
+    """
+    provider_id = await _make_provider(integration_session)
+
+    resp = await integration_client.post(
+        f"/admin/api/upstream-providers/{provider_id}/models",
+        headers={**_admin_headers(), "Content-Type": "application/json"},
+        content=_raw_model_body(provider_id, "huge-price", "9" * 400),
+    )
+
+    assert resp.status_code == 422
+    assert await integration_session.get(ModelRow, ("huge-price", provider_id)) is None
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_non_finite_literal_price_is_rejected(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """A bare ``Infinity``/``NaN`` literal gets the same 422 as any other rate.
+
+    ``json`` accepts both literals, so the edge sees a real float and rejects
+    it — but pydantic echoes the offending value back in the error's ``input``
+    field, and the response encoder runs with ``allow_nan=False``. Serializing
+    that reply raised "Out of range float values are not JSON compliant", so the
+    422 escaped as a 500 and reported a client's bad rate as a server fault.
+    """
+    provider_id = await _make_provider(integration_session)
+
+    for literal in ("Infinity", "-Infinity", "NaN"):
+        resp = await integration_client.post(
+            f"/admin/api/upstream-providers/{provider_id}/models",
+            headers={**_admin_headers(), "Content-Type": "application/json"},
+            content=_raw_model_body(provider_id, "odd-price", literal),
+        )
+
+        assert resp.status_code == 422, literal
+        assert (
+            await integration_session.get(ModelRow, ("odd-price", provider_id)) is None
+        )
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_non_finite_literal_price_is_rejected_in_batch_override(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """The batch path shares the same carrier, so it must answer 422 too."""
+    provider_id = await _make_provider(integration_session)
+
+    resp = await integration_client.post(
+        f"/admin/api/upstream-providers/{provider_id}/batch-override",
+        headers={**_admin_headers(), "Content-Type": "application/json"},
+        content=(
+            '{"models": ['
+            + _raw_model_body(provider_id, "odd-batch", "Infinity")
+            + "]}"
+        ),
+    )
+
+    assert resp.status_code == 422
+    assert await integration_session.get(ModelRow, ("odd-batch", provider_id)) is None
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_admin_model_listing_shows_a_non_finite_stored_rate(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """The operator must be able to see the rate that needs fixing.
+
+    The admin listing is the one view that still carries a row the served
+    catalog holds back, and its encoder rendered a stored ``Infinity`` as
+    ``null`` — indistinguishable from a rate the row never carried.
+    """
+    provider_id = await _make_provider(integration_session)
+    integration_session.add(
+        ModelRow(
+            id="inf-rate",
+            name="inf-rate",
+            description="d",
+            created=0,
+            context_length=8192,
+            architecture=json.dumps(
+                {
+                    "modality": "text",
+                    "input_modalities": ["text"],
+                    "output_modalities": ["text"],
+                    "tokenizer": "unknown",
+                    "instruct_type": None,
+                }
+            ),
+            pricing=json.dumps({"prompt": float("inf"), "completion": 2e-06}),
+            upstream_provider_id=provider_id,
+            enabled=True,
+            forwarded_model_id="inf-rate",
+        )
+    )
+    await integration_session.commit()
+
+    resp = await integration_client.get(
+        f"/admin/api/upstream-providers/{provider_id}/models",
+        headers=_admin_headers(),
+    )
+
+    assert resp.status_code == 200
+    listed = {m["id"]: m for m in resp.json()["db_models"]}
+    assert listed["inf-rate"]["pricing"]["prompt"] == "inf"
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_malformed_auxiliary_rate_is_rejected(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """Validation spans every billable rate, not just the token rates.
+
+    ``prompt``/``completion`` are the rates most prices are built from, but the
+    request, image, search, reasoning and cache rates are billed too. A negative
+    or non-finite value in any of them is the same defect and must be answered
+    the same way.
+    """
+    provider_id = await _make_provider(integration_session)
+
+    for field, bad in (
+        ("request", -1.0),
+        ("image", -0.5),
+        ("web_search", float("inf")),
+        ("internal_reasoning", float("nan")),
+        ("input_cache_read", -1e-06),
+        ("input_cache_write", float("-inf")),
+        ("completion", -1.0),
+    ):
+        resp = await integration_client.post(
+            f"/admin/api/upstream-providers/{provider_id}/models",
+            headers=_admin_headers(),
+            json=_payload(
+                provider_id, model_id="aux-rate", pricing=_pricing(**{field: bad})
+            ),
+        )
+
+        assert resp.status_code == 422, field
+        assert (
+            await integration_session.get(ModelRow, ("aux-rate", provider_id)) is None
+        ), field
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_admin_single_model_shows_a_non_finite_stored_rate(
+    integration_client: AsyncClient, integration_session: AsyncSession
+) -> None:
+    """The single-model view answers like the listing it is opened from.
+
+    It is the other view of a row the served-catalog backstop holds back, so it
+    has the same duty to name the rate that needs fixing rather than rendering
+    it as ``null``.
+    """
+    provider_id = await _make_provider(integration_session)
+    integration_session.add(
+        ModelRow(
+            id="inf-one",
+            name="inf-one",
+            description="d",
+            created=0,
+            context_length=8192,
+            architecture=json.dumps(
+                {
+                    "modality": "text",
+                    "input_modalities": ["text"],
+                    "output_modalities": ["text"],
+                    "tokenizer": "unknown",
+                    "instruct_type": None,
+                }
+            ),
+            pricing=json.dumps({"prompt": float("inf"), "completion": 2e-06}),
+            upstream_provider_id=provider_id,
+            enabled=True,
+            forwarded_model_id="inf-one",
+        )
+    )
+    await integration_session.commit()
+
+    resp = await integration_client.get(
+        f"/admin/api/upstream-providers/{provider_id}/models/inf-one",
+        headers=_admin_headers(),
+    )
+
+    assert resp.status_code == 200
+    assert resp.json()["pricing"]["prompt"] == "inf"
diff --git a/tests/integration/test_served_catalog_rate_backstop.py b/tests/integration/test_served_catalog_rate_backstop.py
new file mode 100644
index 00000000..4acee442
--- /dev/null
+++ b/tests/integration/test_served_catalog_rate_backstop.py
@@ -0,0 +1,255 @@
+"""The served catalog is the last guard between a stored row and a charge.
+
+Stored pricing is JSON written by whatever produced the row — an upstream
+import, an operator, a legacy migration, or a foreign writer that never passed
+the admin edge. So the read path cannot assume a stored rate is a number: it
+must decline to serve a row it cannot bill on, and it must survive a row it
+cannot read at all rather than taking the whole catalog down with it.
+
+The admin listing is deliberately exempt: it includes disabled models and is the
+one view that still shows the operator the row that needs repair.
+"""
+
+from __future__ import annotations
+
+import json
+
+import pytest
+from sqlmodel.ext.asyncio.session import AsyncSession
+
+from routstr.core.db import ModelRow, UpstreamProviderRow
+from routstr.payment.models import list_models
+
+_ARCHITECTURE = json.dumps(
+    {
+        "modality": "text",
+        "input_modalities": ["text"],
+        "output_modalities": ["text"],
+        "tokenizer": "unknown",
+        "instruct_type": None,
+    }
+)
+
+
+async def _make_provider(session: AsyncSession) -> int:
+    provider = UpstreamProviderRow(
+        provider_type="generic",
+        base_url="https://served-upstream.example/v1",
+        api_key="test-key",
+        provider_fee=1.0,
+    )
+    session.add(provider)
+    await session.commit()
+    await session.refresh(provider)
+    assert provider.id is not None
+    return provider.id
+
+
+async def _insert_row(
+    session: AsyncSession,
+    provider_id: int,
+    *,
+    model_id: str,
+    pricing: dict[str, object],
+) -> None:
+    session.add(
+        ModelRow(
+            id=model_id,
+            name=model_id,
+            description="d",
+            created=0,
+            context_length=8192,
+            architecture=_ARCHITECTURE,
+            pricing=json.dumps(pricing),
+            upstream_provider_id=provider_id,
+            enabled=True,
+            forwarded_model_id=model_id,
+        )
+    )
+    await session.commit()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "bad_rate",
+    [float("nan"), float("inf"), -1.0],
+    ids=["nan", "inf", "negative"],
+)
+async def test_served_catalog_excludes_a_malformed_stored_rate(
+    integration_session: AsyncSession, bad_rate: float
+) -> None:
+    """A stored rate that is not a number must not be advertised.
+
+    Zero is a real price and a free model is servable, but a negative or
+    non-finite rate is not a price at all: serving it advertises a rate the cost
+    calculation cannot bill on, so every request falls through to the flat
+    maximum reservation — or, for a negative rate, bills an amount settlement
+    credits back to the caller.
+    """
+    provider_id = await _make_provider(integration_session)
+    await _insert_row(
+        integration_session,
+        provider_id,
+        model_id="good",
+        pricing={"prompt": 1e-06, "completion": 2e-06},
+    )
+    await _insert_row(
+        integration_session,
+        provider_id,
+        model_id="bad-rate",
+        pricing={"prompt": bad_rate, "completion": 2e-06},
+    )
+
+    served = {m.id for m in await list_models(integration_session, provider_id)}
+
+    assert served == {"good"}
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_free_stored_price_is_still_served(
+    integration_session: AsyncSession,
+) -> None:
+    """Zero is a real price. Rejecting malformed rates must not also drop a row
+    priced at zero, which is a free model and not a broken one."""
+    provider_id = await _make_provider(integration_session)
+    await _insert_row(
+        integration_session,
+        provider_id,
+        model_id="free",
+        pricing={"prompt": 0.0, "completion": 0.0},
+    )
+
+    served = {m.id for m in await list_models(integration_session, provider_id)}
+
+    assert served == {"free"}
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_admin_listing_still_shows_a_malformed_stored_rate(
+    integration_session: AsyncSession,
+) -> None:
+    """The operator has to be able to see the row that needs fixing.
+
+    The backstop keeps a malformed row out of the *served* catalog. The listing
+    that includes disabled models is the one view where the row must still
+    appear, or the operator loses the ability to repair it.
+    """
+    provider_id = await _make_provider(integration_session)
+    await _insert_row(
+        integration_session,
+        provider_id,
+        model_id="bad-rate",
+        pricing={"prompt": -1.0, "completion": 2e-06},
+    )
+
+    listed = {
+        m.id
+        for m in await list_models(
+            integration_session, provider_id, include_disabled=True
+        )
+    }
+
+    assert listed == {"bad-rate"}
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_one_unreadable_stored_price_does_not_blank_the_catalog(
+    integration_session: AsyncSession,
+) -> None:
+    """A single unparseable row must cost that row, not every model on the node.
+
+    Stored pricing is JSON written by whatever produced the row, so a
+    non-numeric rate is reachable from a legacy import or a foreign writer.
+    Parsing it raises out of the row-to-model conversion, and because the
+    conversion ran inside the catalog loop the exception took the whole listing
+    with it — one bad row and the node advertised nothing at all.
+    """
+    provider_id = await _make_provider(integration_session)
+    await _insert_row(
+        integration_session,
+        provider_id,
+        model_id="good",
+        pricing={"prompt": 1e-06, "completion": 2e-06},
+    )
+    await _insert_row(
+        integration_session,
+        provider_id,
+        model_id="unreadable",
+        pricing={"prompt": "not-a-number", "completion": 2e-06},
+    )
+
+    served = {m.id for m in await list_models(integration_session, provider_id)}
+
+    assert served == {"good"}
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "field",
+    [
+        "image",
+        "web_search",
+        "internal_reasoning",
+        "input_cache_read",
+        "input_cache_write",
+    ],
+)
+async def test_served_catalog_excludes_a_malformed_auxiliary_rate(
+    integration_session: AsyncSession, field: str
+) -> None:
+    """The backstop covers every billable rate, not only the token rates.
+
+    A price whose ``prompt``/``completion`` are sound can still carry a
+    malformed request, image, search, reasoning or cache rate — the catalog
+    import filter never inspects those — and the request that hits one is billed
+    against it just the same.
+    """
+    provider_id = await _make_provider(integration_session)
+    await _insert_row(
+        integration_session,
+        provider_id,
+        model_id="good",
+        pricing={"prompt": 1e-06, "completion": 2e-06},
+    )
+    await _insert_row(
+        integration_session,
+        provider_id,
+        model_id="bad-aux",
+        pricing={"prompt": 1e-06, "completion": 2e-06, field: -1.0},
+    )
+
+    served = {m.id for m in await list_models(integration_session, provider_id)}
+
+    assert served == {"good"}
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_a_negative_request_rate_is_clamped_on_read_and_still_served(
+    integration_session: AsyncSession,
+) -> None:
+    """``request`` is the one billable rate the row-to-model conversion repairs.
+
+    It clamps a negative stored ``request`` to zero before the price is built,
+    so the backstop never sees one and the row is served at a zero request rate
+    — money-safe, and the reason ``request`` is absent from the list of rates
+    above. Pinned here so that if the clamp goes, this rate joins that list
+    rather than quietly becoming the one unguarded field.
+    """
+    provider_id = await _make_provider(integration_session)
+    await _insert_row(
+        integration_session,
+        provider_id,
+        model_id="neg-request",
+        pricing={"prompt": 1e-06, "completion": 2e-06, "request": -1.0},
+    )
+
+    served = await list_models(integration_session, provider_id)
+
+    assert [m.id for m in served] == ["neg-request"]
+    assert served[0].pricing.request == 0.0
diff --git a/tests/unit/test_algorithm.py b/tests/unit/test_algorithm.py
index 5d31af2e..f5c875f9 100644
--- a/tests/unit/test_algorithm.py
+++ b/tests/unit/test_algorithm.py
@@ -954,3 +954,104 @@ def test_create_model_mappings_uppercase_prefixed_base_keeps_top_tier() -> None:
 
     assert provider_map["qwen2.5-72b"][0] == (prefixed_cheap, prefixed_provider)
     assert unique_models["qwen2.5-72b"].upstream_provider_id == "prefixed"
+
+
+def test_create_model_mappings_excludes_a_malformed_price() -> None:
+    """A rate that is not a number must not be routable.
+
+    A negative or non-finite rate reads as a real price to every truthiness
+    check, so the candidate was built into the map and served. The cost
+    calculation cannot price on such a rate, so every request on the model fell
+    through to the flat maximum reservation — or, for a negative rate, billed a
+    negative amount that settlement credits back to the caller.
+    """
+    healthy = create_test_model("healthy-model")
+    for bad_rate in (float("nan"), float("inf"), -1.0):
+        broken = create_test_model("broken-model", prompt_price=bad_rate)
+        provider = create_test_provider(
+            "custom",
+            "https://custom.example/v1",
+            db_id=1,
+            models=[broken, healthy],
+        )
+
+        _, provider_map, unique_models = create_model_mappings(
+            upstreams=[provider],
+            overrides_by_key={},
+            disabled_model_keys=set(),
+        )
+
+        assert "broken-model" not in provider_map, bad_rate
+        assert "broken-model" not in unique_models, bad_rate
+        # One unroutable candidate must not cost the provider its other models.
+        assert "healthy-model" in provider_map, bad_rate
+
+
+def test_create_model_mappings_excludes_an_override_with_a_malformed_price(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """An override row carrying a malformed rate is unroutable too.
+
+    An override replaces the discovered model's price, so a provider whose
+    catalog is sound still routes at whatever the row says. The guard has to sit
+    after the override is applied, not before it.
+    """
+    discovered = create_test_model("shared-model")
+    provider = create_test_provider(
+        "custom", "https://custom.example/v1", db_id=3, models=[discovered]
+    )
+    override_model = create_test_model("shared-model", prompt_price=float("-inf"))
+
+    monkeypatch.setattr(
+        "routstr.payment.models._row_to_model",
+        lambda *args, **kwargs: override_model,
+    )
+    override_row = SimpleNamespace(
+        id="shared-model", upstream_provider_id=3, enabled=True
+    )
+
+    _, provider_map, unique_models = create_model_mappings(
+        upstreams=[provider],
+        overrides_by_key={("shared-model", 3): (override_row, 1.0)},
+        disabled_model_keys=set(),
+    )
+
+    assert "shared-model" not in provider_map
+    assert "shared-model" not in unique_models
+
+
+def test_create_model_mappings_survives_an_unreadable_override_row(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """One row that cannot be read must not empty the whole routing map.
+
+    Converting an override while walking a provider's catalog let the exception
+    unwind the entire map build: the node came up routing nothing. The sibling
+    loop over override-only rows already skips and logs such a row.
+    """
+    broken = create_test_model("broken-model")
+    healthy = create_test_model("healthy-model")
+    provider = create_test_provider(
+        "custom",
+        "https://custom.example/v1",
+        db_id=5,
+        models=[broken, healthy],
+    )
+
+    def raising_row_to_model(row: Any, *args: Any, **kwargs: Any) -> Model:
+        raise ValueError("value is not a valid float")
+
+    monkeypatch.setattr("routstr.payment.models._row_to_model", raising_row_to_model)
+    override_row = SimpleNamespace(
+        id="broken-model", upstream_provider_id=5, enabled=True
+    )
+
+    _, provider_map, unique_models = create_model_mappings(
+        upstreams=[provider],
+        overrides_by_key={("broken-model", 5): (override_row, 1.0)},
+        disabled_model_keys=set(),
+    )
+
+    assert "broken-model" not in provider_map
+    assert "healthy-model" in provider_map
+    assert "healthy-model" in unique_models
diff --git a/tests/unit/test_pricing_rate_validation.py b/tests/unit/test_pricing_rate_validation.py
new file mode 100644
index 00000000..b3e538c7
--- /dev/null
+++ b/tests/unit/test_pricing_rate_validation.py
@@ -0,0 +1,491 @@
+"""Tests that an unusable rate never reaches the money math.
+
+A billable rate is usable only when it is finite and non-negative. Prices reach
+the node from upstream catalogs, an operator's admin edit, a legacy database row
+and the BTC/USD feed, and each of those can deliver ``NaN``, ``±inf`` or a
+negative — ``json.loads`` accepts the bare ``NaN``/``Infinity`` literals and
+overflows ``1e999`` to ``inf``.
+
+These tests cover the guards between such a value and a charge: the token-rate
+gate that decides a model cannot be priced, the upstream-reported USD cost, the
+exchange-rate feed, and the stored-row read path. They assert the node declines
+to price the request rather than billing a nonsensical amount or raising after
+the response has already been served.
+"""
+
+from __future__ import annotations
+
+import math
+from collections.abc import Iterator
+from typing import Any
+from unittest.mock import patch
+
+import pytest
+
+from routstr.payment.cost_calculation import (
+    CostData,
+    MaxCostData,
+    calculate_cost,
+)
+from routstr.payment.models import (
+    Architecture,
+    Model,
+    Pricing,
+)
+
+
+@pytest.fixture(autouse=True)
+def patch_sats_usd_price() -> Iterator[None]:
+    """Pin the exchange rate; these tests are about the rates, not the feed."""
+    with patch("routstr.payment.cost_calculation.sats_usd_price", return_value=5.0e-5):
+        yield
+
+
+def _architecture() -> Architecture:
+    return Architecture(
+        modality="text",
+        input_modalities=["text"],
+        output_modalities=["text"],
+        tokenizer="unknown",
+        instruct_type=None,
+    )
+
+
+def _model(sats_pricing: Pricing) -> Model:
+    return Model(
+        id="m",
+        name="m",
+        created=0,
+        description="d",
+        context_length=8192,
+        architecture=_architecture(),
+        pricing=Pricing(prompt=1e-06, completion=2e-06),
+        sats_pricing=sats_pricing,
+    )
+
+
+def _usage_response() -> dict[str, Any]:
+    return {"model": "m", "usage": {"prompt_tokens": 1000, "completion_tokens": 500}}
+
+
+@pytest.mark.parametrize(
+    "bad_rate",
+    [float("nan"), float("inf"), -5.0],
+    ids=["nan", "inf", "negative"],
+)
+@pytest.mark.asyncio
+async def test_unusable_token_rate_falls_back_to_max_cost(bad_rate: float) -> None:
+    """An unusable configured rate must not be billed on.
+
+    It reached the token math, which raises after the response was already
+    served — where the streaming handlers swallow it and the request goes
+    unbilled.
+    """
+    model = _model(Pricing(prompt=bad_rate, completion=1.0))
+
+    cost = await calculate_cost(_usage_response(), max_cost=1234, model_obj=model)
+
+    assert isinstance(cost, MaxCostData)
+    assert cost.total_msats == 1234
+
+
+@pytest.mark.parametrize(
+    ("prompt", "completion", "expected_msats"),
+    [(0.0, 0.0, 0), (0.0, 2e-06, 1), (1e-06, 0.0, 1)],
+    ids=["free", "free-input", "free-output"],
+)
+@pytest.mark.asyncio
+async def test_a_rate_of_zero_is_billed_as_free_not_as_missing(
+    prompt: float, completion: float, expected_msats: int
+) -> None:
+    """Zero is a price, and the request must be billed on it.
+
+    The gate that decides a model has no token pricing was a truthiness test, so
+    a free rate read as an absent one and the request was charged the whole
+    reservation instead — on a model priced at zero for that side, which is a
+    price the catalog serves and the router routes.
+    """
+    model = _model(Pricing(prompt=prompt, completion=completion))
+
+    cost = await calculate_cost(_usage_response(), max_cost=1234, model_obj=model)
+
+    assert isinstance(cost, CostData)
+    assert cost.total_msats == expected_msats
+
+
+@pytest.mark.parametrize(
+    "junk", [float("inf"), float("nan"), "Infinity"], ids=["inf", "nan", "inf-string"]
+)
+@pytest.mark.asyncio
+async def test_junk_cost_component_still_bills_the_reported_total(junk: Any) -> None:
+    """A malformed component must not discard the upstream's real total cost.
+
+    ``cost_details`` only splits the total across input and output; the total is
+    the authoritative billed amount. A non-finite component poisoned the split,
+    and the request fell through to token estimation for a fraction of it.
+    """
+    model = _model(Pricing(prompt=1e-06, completion=2e-06))
+    response = {
+        "model": "m",
+        "usage": {
+            "prompt_tokens": 1000,
+            "completion_tokens": 500,
+            "cost": 0.01,
+            "cost_details": {"input_cost": junk, "output_cost": 0.004},
+        },
+    }
+
+    cost = await calculate_cost(response, max_cost=9999, model_obj=model)
+
+    assert isinstance(cost, CostData)
+    # $0.01 at 5.0e-5 USD/sat = 200 sats = 200_000 msats.
+    assert cost.total_msats == 200000
+    assert cost.total_usd == pytest.approx(0.01)
+
+
+@pytest.mark.asyncio
+async def test_junk_cost_component_falls_back_to_its_alternate_field() -> None:
+    """A malformed component must not shadow the field that would have replaced it.
+
+    Each side of the split has two spellings and the second is a fallback for a
+    missing first. ``inf`` and ``NaN`` are both truthy, so a malformed
+    ``input_cost`` won that choice before anything checked whether it was a
+    number, and the usable figure beside it was never read — the input side was
+    then billed at nothing and the whole total landed on output.
+    """
+    model = _model(Pricing(prompt=1e-06, completion=2e-06))
+    response = {
+        "model": "m",
+        "usage": {
+            "prompt_tokens": 1000,
+            "completion_tokens": 500,
+            "cost": 0.01,
+            "cost_details": {
+                "input_cost": float("inf"),
+                "upstream_inference_prompt_cost": 0.006,
+                "output_cost": 0.004,
+            },
+        },
+    }
+
+    cost = await calculate_cost(response, max_cost=9999, model_obj=model)
+
+    assert isinstance(cost, CostData)
+    # $0.01 at 5.0e-5 USD/sat = 200_000 msats, split 0.006 : 0.004.
+    assert cost.total_msats == 200000
+    assert (cost.input_msats, cost.output_msats) == (120000, 80000)
+
+
+@pytest.mark.asyncio
+async def test_non_finite_reported_cost_is_not_a_cost() -> None:
+    """An upstream-reported ``Infinity`` cost is junk, not an infinite charge.
+
+    ``json.loads`` accepts the bare ``Infinity`` literal, so a compromised or
+    buggy upstream can put one in ``usage.cost``. It must not be treated as a
+    positive USD cost at all — the request falls through to the node's own token
+    pricing instead.
+    """
+    model = _model(Pricing(prompt=1e-06, completion=2e-06))
+    response = {
+        "model": "m",
+        "usage": {
+            "prompt_tokens": 1000,
+            "completion_tokens": 500,
+            "cost": float("inf"),
+        },
+    }
+
+    cost = await calculate_cost(response, max_cost=9999, model_obj=model)
+
+    assert isinstance(cost, CostData)
+    assert math.isfinite(cost.total_usd)
+    assert cost.total_msats == 2
+
+
+class _ExchangeResponse:
+    def __init__(self, payload: dict[str, Any]) -> None:
+        self._payload = payload
+
+    def json(self) -> dict[str, Any]:
+        # A quote given as an exception stands for a response body that never
+        # produced one: an exchange answering with an HTML error page raises
+        # out of `.json()` before any price is read.
+        quote = next(iter(self._payload.values()))
+        if isinstance(quote, BaseException):
+            raise quote
+        return self._payload
+
+
+class _ExchangeClient:
+    """Answers each exchange endpoint with a caller-supplied quote."""
+
+    def __init__(self, quotes: dict[str, Any]) -> None:
+        self._quotes = quotes
+
+    async def get(self, url: str) -> _ExchangeResponse:
+        if "kraken" in url:
+            quote = self._quotes["kraken"]
+            if isinstance(quote, BaseException):
+                return _ExchangeResponse({"error": quote})
+            return _ExchangeResponse({"result": {"XXBTZUSD": {"c": [quote]}}})
+        if "coinbase" in url:
+            return _ExchangeResponse({"data": {"amount": self._quotes["coinbase"]}})
+        return _ExchangeResponse({"price": self._quotes["binance"]})
+
+
+class _AsyncCtx:
+    def __init__(self, client: _ExchangeClient) -> None:
+        self._client = client
+
+    async def __aenter__(self) -> _ExchangeClient:
+        return self._client
+
+    async def __aexit__(self, *exc: object) -> bool:
+        return False
+
+
+@pytest.fixture
+def refresh_price_with() -> Iterator[Any]:
+    """Refresh the node's BTC/USD price from caller-supplied exchange quotes.
+
+    Restores the module's cached price afterwards so one test cannot set the
+    rate another one bills at.
+    """
+    import routstr.payment.price as price_module
+
+    previous = (price_module.BTC_USD_PRICE, price_module.SATS_USD_PRICE)
+
+    async def _run(quotes: dict[str, Any], last_good: float | None = None) -> None:
+        price_module.BTC_USD_PRICE = last_good
+        price_module.SATS_USD_PRICE = (
+            None if last_good is None else last_good / 100_000_000
+        )
+        with patch.object(
+            price_module.httpx,
+            "AsyncClient",
+            lambda *a, **k: _AsyncCtx(_ExchangeClient(quotes)),
+        ):
+            await price_module._update_prices()
+
+    yield _run
+
+    price_module.BTC_USD_PRICE, price_module.SATS_USD_PRICE = previous
+
+
+@pytest.mark.parametrize(
+    "bad_quote",
+    ["0", "0.00000000", "-1", "NaN", "Infinity", "N/A"],
+    ids=["zero", "zero-padded", "negative", "nan", "infinity", "non-numeric"],
+)
+@pytest.mark.asyncio
+async def test_unusable_exchange_quote_does_not_set_the_node_price(
+    bad_quote: str, refresh_price_with: Any
+) -> None:
+    """One exchange returning junk must not set the price the node bills at.
+
+    The feed takes the ``min()`` of what it collects, so an unusable quote does
+    not merely join the sample — it *wins*. The two healthy quotes must still
+    price the node.
+    """
+    from routstr.payment.price import btc_usd_price
+
+    await refresh_price_with(
+        {"kraken": bad_quote, "coinbase": "100000.0", "binance": "100000.0"}
+    )
+
+    assert btc_usd_price() == pytest.approx(100000.0)
+
+
+@pytest.mark.asyncio
+async def test_boolean_exchange_quote_does_not_set_the_node_price(
+    refresh_price_with: Any,
+) -> None:
+    """A boolean in the price field is a shape change, not a $1 bitcoin.
+
+    ``float(True)`` is ``1.0``, which is finite and positive, so a payload whose
+    price field turned into a boolean passes every numeric guard — and then
+    *wins* the ``min()``, pricing the whole node at one dollar per bitcoin.
+    """
+    from routstr.payment.price import btc_usd_price
+
+    await refresh_price_with(
+        {"kraken": True, "coinbase": "100000.0", "binance": "100000.0"}
+    )
+
+    assert btc_usd_price() == pytest.approx(100000.0)
+
+
+@pytest.mark.asyncio
+async def test_an_underflowing_exchange_quote_does_not_set_the_node_price(
+    refresh_price_with: Any,
+) -> None:
+    """A quote too small to survive the sats conversion is not a price.
+
+    ``1e-320`` is positive, so it passes the guards and wins the ``min()``, but
+    the node prices in sats and ``1e-320 / 100_000_000`` underflows to ``0.0``
+    — a zero sats price divides by zero on every model's rate.
+    """
+    from routstr.payment.price import btc_usd_price
+
+    await refresh_price_with(
+        {"kraken": "1e-320", "coinbase": "100000.0", "binance": "100000.0"}
+    )
+
+    assert btc_usd_price() == pytest.approx(100000.0)
+
+
+@pytest.mark.asyncio
+async def test_an_unreadable_exchange_response_drops_only_that_quote(
+    refresh_price_with: Any,
+) -> None:
+    """An exchange whose response never yields a quote costs one quote.
+
+    The price is aggregated across three exchanges so that one of them having a
+    bad day is survivable; unhandled, the raise aborted the whole aggregation.
+    """
+    from routstr.payment.price import btc_usd_price
+
+    await refresh_price_with(
+        {
+            "kraken": ValueError("Expecting value: line 1 column 1 (char 0)"),
+            "coinbase": "100000.0",
+            "binance": "100000.0",
+        }
+    )
+
+    assert btc_usd_price() == pytest.approx(100000.0)
+
+
+@pytest.mark.asyncio
+async def test_all_quotes_unusable_keeps_the_last_good_price(
+    refresh_price_with: Any,
+) -> None:
+    """When every quote is junk the node keeps the last price it trusted.
+
+    Adopting ``0`` or ``NaN`` because it was the only thing on offer would take
+    out billing for every model at once; skipping the update degrades to a stale
+    rate, which is the safe direction and what an unreachable exchange already
+    does.
+    """
+    from routstr.payment.price import btc_usd_price
+
+    await refresh_price_with(
+        {"kraken": "0", "coinbase": "NaN", "binance": "-3"}, last_good=90000.0
+    )
+
+    assert btc_usd_price() == pytest.approx(90000.0)
+
+
+# ---------------------------------------------------------------------------
+# Catalog ingest — a malformed rate must never become a stored price
+# ---------------------------------------------------------------------------
+
+
+class _CatalogResponse:
+    def __init__(self, payload: dict[str, Any]) -> None:
+        self._payload = payload
+
+    def raise_for_status(self) -> None:
+        return None
+
+    def json(self) -> dict[str, Any]:
+        return self._payload
+
+
+class _CatalogClient:
+    """Stands in for ``httpx.AsyncClient`` against the OpenRouter catalog."""
+
+    def __init__(self, models: list[dict[str, Any]]) -> None:
+        self._models = models
+
+    async def __aenter__(self) -> "_CatalogClient":
+        return self
+
+    async def __aexit__(self, *exc: object) -> bool:
+        return False
+
+    async def get(self, url: str, timeout: int | None = None) -> _CatalogResponse:
+        if url.endswith("/embeddings/models"):
+            return _CatalogResponse({"data": []})
+        return _CatalogResponse({"data": self._models})
+
+
+def _catalog_entry(model_id: str, pricing: dict[str, Any]) -> dict[str, Any]:
+    return {"id": model_id, "name": model_id, "pricing": pricing}
+
+
+def _patch_openrouter_catalog(models: list[dict[str, Any]]) -> Any:
+    return patch(
+        "routstr.payment.models.httpx.AsyncClient",
+        lambda *args, **kwargs: _CatalogClient(models),
+    )
+
+
+@pytest.mark.parametrize(
+    "bad_rate",
+    [float("nan"), float("inf"), float("-inf")],
+    ids=["nan", "inf", "negative-inf"],
+)
+@pytest.mark.asyncio
+async def test_non_finite_catalog_rate_is_not_imported(bad_rate: float) -> None:
+    """A non-finite rate in the upstream catalog is junk, not a price.
+
+    ``json.loads`` accepts the bare ``NaN``/``Infinity`` literals and overflows
+    ``1e999`` to ``inf``, so an upstream feed can deliver one. The import filter
+    rejects a negative and a both-zero price, but every comparison with ``NaN``
+    is False and ``inf`` reads as a large positive, so both sailed through and
+    became a stored price the node would advertise and bill on.
+    """
+    with _patch_openrouter_catalog(
+        [
+            _catalog_entry("bad", {"prompt": bad_rate, "completion": "0.000002"}),
+            _catalog_entry("good", {"prompt": "0.000001", "completion": "0.000002"}),
+        ]
+    ):
+        from routstr.payment.models import async_fetch_openrouter_models
+
+        models = await async_fetch_openrouter_models()
+
+    assert [m["id"] for m in models] == ["good"]
+
+
+@pytest.mark.asyncio
+async def test_oversized_catalog_rate_does_not_empty_the_catalog() -> None:
+    """An integer too large to be a float must cost one model, not all of them.
+
+    ``float()`` raises ``OverflowError`` — not ``ValueError`` — for such a
+    value, so the coercion guard in the import filter did not catch it and the
+    exception unwound the whole fetch. The node then imported nothing at all
+    from an upstream whose catalog was fine apart from one entry.
+    """
+    with _patch_openrouter_catalog(
+        [
+            _catalog_entry("bad", {"prompt": 10**400, "completion": 2}),
+            _catalog_entry("good", {"prompt": "0.000001", "completion": "0.000002"}),
+        ]
+    ):
+        from routstr.payment.models import async_fetch_openrouter_models
+
+        models = await async_fetch_openrouter_models()
+
+    assert [m["id"] for m in models] == ["good"]
+
+
+@pytest.mark.asyncio
+async def test_boolean_catalog_rate_is_not_imported() -> None:
+    """A JSON ``true`` is a change of shape, not a price.
+
+    Python coerces it to a finite, positive ``1.0`` — a dollar per token — so it
+    passes every numeric guard and must be rejected before coercion.
+    """
+    with _patch_openrouter_catalog(
+        [
+            _catalog_entry("bad", {"prompt": True, "completion": "0.000002"}),
+            _catalog_entry("good", {"prompt": "0.000001", "completion": "0.000002"}),
+        ]
+    ):
+        from routstr.payment.models import async_fetch_openrouter_models
+
+        models = await async_fetch_openrouter_models()
+
+    assert [m["id"] for m in models] == ["good"]
diff --git a/tests/unit/test_upstream_generic.py b/tests/unit/test_upstream_generic.py
index 39daff5c..2e6fd56e 100644
--- a/tests/unit/test_upstream_generic.py
+++ b/tests/unit/test_upstream_generic.py
@@ -522,3 +522,205 @@ async def test_unresolvable_model_fails_closed(
         for rec in caplog.records
         if rec.levelno >= logging.WARNING
     )
+
+
+# ---------------------------------------------------------------------------
+# rate validation — a malformed rate is not a resolved price, at any rung
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_non_finite_litellm_rate_is_not_a_resolved_price() -> None:
+    """A non-finite entry in the cost map must not answer the resolution chain.
+
+    The litellm rung rejects negatives and a both-zero entry, but every
+    comparison with ``NaN`` is False and ``inf`` reads as a large positive, so
+    either would be reported as a resolved price — enabling the model at a rate
+    the node cannot bill on. Fail closed instead: the model imports disabled,
+    which is what "no source knows this price" already means here.
+    """
+    payload = {
+        "data": [
+            {"id": "nan-priced-model", "object": "model", "owned_by": "mystery"},
+        ]
+    }
+    cost_entry = {
+        "input_cost_per_token": float("nan"),
+        "output_cost_per_token": float("inf"),
+        "max_input_tokens": 8192,
+    }
+
+    with _patch_models_endpoint(payload):
+        or_feed = AsyncMock(return_value=[])
+        with patch("routstr.payment.models.litellm_cost_entry", lambda _id: cost_entry):
+            with patch("routstr.payment.models.async_fetch_openrouter_models", or_feed):
+                models = await GenericUpstreamProvider(
+                    base_url="http://x"
+                ).fetch_models()
+
+    model = _model_by_id(models, "nan-priced-model")
+    assert model.enabled is False
+    assert model.pricing.prompt == 0.0
+    assert model.pricing.completion == 0.0
+
+
+@pytest.mark.asyncio
+async def test_non_finite_openrouter_rate_is_not_a_resolved_price() -> None:
+    """``float("Infinity")`` parses happily from a feed string, so the
+    OpenRouter rung's coercion accepted it and reported an infinite rate as a
+    resolved price. It is not a price; the model must import disabled."""
+    payload = {
+        "data": [
+            {"id": "or-nonfinite-xyz", "object": "model", "owned_by": "mystery"},
+        ]
+    }
+    feed = [
+        {
+            "id": "or-nonfinite-xyz",
+            "pricing": {"prompt": "Infinity", "completion": "0.000002"},
+            "context_length": 8192,
+        }
+    ]
+
+    with _patch_models_endpoint(payload):
+        or_feed = AsyncMock(return_value=feed)
+        with patch("routstr.payment.models.async_fetch_openrouter_models", or_feed):
+            models = await GenericUpstreamProvider(base_url="http://x").fetch_models()
+
+    model = _model_by_id(models, "or-nonfinite-xyz")
+    assert model.enabled is False
+    assert model.pricing.prompt == 0.0
+    assert model.pricing.completion == 0.0
+
+
+@pytest.mark.asyncio
+async def test_non_finite_openrouter_cache_rate_is_dropped_not_carried() -> None:
+    """A malformed *cache* rate must cost the cache rate, not the model.
+
+    The catalog import filter only inspects prompt and completion, so an entry
+    with two sound token rates and an unusable ``input_cache_read`` reaches the
+    resolver intact. Carrying that rate through would price every cached input
+    token at ``inf``; dropping it falls back to the full input rate, which is
+    what a missing cache rate already means.
+    """
+    payload = {
+        "data": [
+            {"id": "or-badcache-xyz", "object": "model", "owned_by": "mystery"},
+        ]
+    }
+    feed = [
+        {
+            "id": "or-badcache-xyz",
+            "pricing": {
+                "prompt": "0.000001",
+                "completion": "0.000002",
+                "input_cache_read": "Infinity",
+            },
+            "context_length": 8192,
+        }
+    ]
+
+    with _patch_models_endpoint(payload):
+        or_feed = AsyncMock(return_value=feed)
+        with patch("routstr.payment.models.async_fetch_openrouter_models", or_feed):
+            models = await GenericUpstreamProvider(base_url="http://x").fetch_models()
+
+    model = _model_by_id(models, "or-badcache-xyz")
+    assert model.enabled is True
+    assert model.pricing.prompt == pytest.approx(1e-06)
+    assert model.pricing.input_cache_read == 0.0
+
+
+@pytest.mark.asyncio
+async def test_negative_openrouter_cache_rate_is_dropped_not_carried() -> None:
+    """A negative rate is as unusable as a non-finite one, and arrives the same way.
+
+    The coercion that reads a feed price rejected ``NaN``/``inf`` but returned a
+    negative unchanged, and the catalog import filter that would have caught one
+    inspects only prompt and completion. So a negative cache rate was the single
+    malformed value that still reached a stored price — where it prices cached
+    input tokens at a credit rather than a charge.
+    """
+    payload = {
+        "data": [
+            {"id": "or-negcache-xyz", "object": "model", "owned_by": "mystery"},
+        ]
+    }
+    feed = [
+        {
+            "id": "or-negcache-xyz",
+            "pricing": {
+                "prompt": "0.000001",
+                "completion": "0.000002",
+                "input_cache_read": "-0.0000005",
+            },
+            "context_length": 8192,
+        }
+    ]
+
+    with _patch_models_endpoint(payload):
+        or_feed = AsyncMock(return_value=feed)
+        with patch("routstr.payment.models.async_fetch_openrouter_models", or_feed):
+            models = await GenericUpstreamProvider(base_url="http://x").fetch_models()
+
+    model = _model_by_id(models, "or-negcache-xyz")
+    assert model.enabled is True
+    assert model.pricing.prompt == pytest.approx(1e-06)
+    assert model.pricing.input_cache_read == 0.0
+
+
+@pytest.mark.asyncio
+async def test_boolean_litellm_rate_is_not_a_resolved_price() -> None:
+    """``isinstance(True, int)`` is True, so a boolean passed the cost map's own
+    numeric check and resolved as a rate of ``1.0`` — a dollar per token."""
+    payload = {
+        "data": [
+            {"id": "bool-priced-model", "object": "model", "owned_by": "mystery"},
+        ]
+    }
+    cost_entry = {
+        "input_cost_per_token": True,
+        "output_cost_per_token": 2e-06,
+        "max_input_tokens": 8192,
+    }
+
+    with _patch_models_endpoint(payload):
+        or_feed = AsyncMock(return_value=[])
+        with patch("routstr.payment.models.litellm_cost_entry", lambda _id: cost_entry):
+            with patch("routstr.payment.models.async_fetch_openrouter_models", or_feed):
+                models = await GenericUpstreamProvider(
+                    base_url="http://x"
+                ).fetch_models()
+
+    model = _model_by_id(models, "bool-priced-model")
+    assert model.enabled is False
+    assert model.pricing.prompt == 0.0
+    assert model.pricing.completion == 0.0
+
+
+@pytest.mark.asyncio
+async def test_boolean_openrouter_rate_is_not_a_resolved_price() -> None:
+    """The same coercion reads a feed's ``true`` as a rate of ``1.0``; the model
+    must import disabled rather than priced at a dollar per token."""
+    payload = {
+        "data": [
+            {"id": "or-bool-xyz", "object": "model", "owned_by": "mystery"},
+        ]
+    }
+    feed = [
+        {
+            "id": "or-bool-xyz",
+            "pricing": {"prompt": True, "completion": "0.000002"},
+            "context_length": 8192,
+        }
+    ]
+
+    with _patch_models_endpoint(payload):
+        or_feed = AsyncMock(return_value=feed)
+        with patch("routstr.payment.models.async_fetch_openrouter_models", or_feed):
+            models = await GenericUpstreamProvider(base_url="http://x").fetch_models()
+
+    model = _model_by_id(models, "or-bool-xyz")
+    assert model.enabled is False
+    assert model.pricing.prompt == 0.0
+    assert model.pricing.completion == 0.0