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Author SHA1 Message Date
9qeklajc d96dc20e86 secure endpoint 2026-06-07 15:18:49 +02:00
9qeklajcandGitHub 934afaa091 Merge pull request #544 from Routstr/pr-reactive-correction
feat: reactive request-correction retry for recoverable upstream 400s
2026-06-07 15:09:18 +02:00
9qeklajc 9ef01acac9 Merge branch 'main' into pr-reactive-correction 2026-06-07 13:10:29 +02:00
9qeklajcandGitHub cbd38c15fe Merge pull request #543 from Routstr/pr-sse-parser
fix: buffer-based SSE parser for all supported providers
2026-06-07 13:06:16 +02:00
9qeklajc 06c8a071a5 feat: reactive request-correction retry for recoverable upstream 400s 2026-06-07 13:00:19 +02:00
5 changed files with 642 additions and 44 deletions
+46 -7
View File
@@ -3,7 +3,7 @@ import json
import random
import httpx
from fastapi import APIRouter, Depends
from fastapi import APIRouter, Depends, HTTPException, Request
from pydantic import BaseModel as V2BaseModel
from pydantic.v1 import BaseModel
from sqlmodel.ext.asyncio.session import AsyncSession
@@ -17,6 +17,24 @@ logger = get_logger(__name__)
models_router = APIRouter()
_MODEL_TEST_ENDPOINT_PATHS = {
"chat-completions": "chat/completions",
"completions": "completions",
"embeddings": "embeddings",
"responses": "responses",
}
# Cap the caller-supplied test payload to avoid forwarding oversized bodies
# upstream on the operator's credentials.
_MODEL_TEST_MAX_REQUEST_BYTES = 64 * 1024
async def _require_admin_api(request: Request) -> None:
"""Require admin auth without creating an import-time cycle with core.admin."""
from ..core.admin import require_admin_api
await require_admin_api(request)
class Architecture(BaseModel):
modality: str
@@ -418,7 +436,9 @@ class ModelTestRequest(V2BaseModel):
request_data: dict
@models_router.post("/api/models/test")
@models_router.post(
"/api/models/test", dependencies=[Depends(_require_admin_api)]
)
async def test_model(
payload: ModelTestRequest,
session: AsyncSession = Depends(get_session),
@@ -446,16 +466,35 @@ async def test_model(
"status_code": 404,
}
base_url = provider.base_url.rstrip("/")
if payload.endpoint_type == "chat-completions":
url = f"{base_url}/chat/completions"
else:
url = f"{base_url}/{payload.endpoint_type}"
endpoint_path = _MODEL_TEST_ENDPOINT_PATHS.get(payload.endpoint_type)
if endpoint_path is None:
raise HTTPException(status_code=400, detail="Unsupported endpoint_type")
actual_model_id = model_row.forwarded_model_id or model_row.id
request_data = dict(payload.request_data)
request_data["model"] = actual_model_id
try:
request_size = len(json.dumps(request_data).encode("utf-8"))
except (TypeError, ValueError):
raise HTTPException(status_code=400, detail="Invalid request_data")
if request_size > _MODEL_TEST_MAX_REQUEST_BYTES:
raise HTTPException(status_code=413, detail="request_data too large")
base_url = provider.base_url.rstrip("/")
url = f"{base_url}/{endpoint_path}"
logger.info(
"admin model test",
extra={
"model_id": payload.model_id,
"forwarded_model_id": actual_model_id,
"endpoint_type": payload.endpoint_type,
"upstream_provider_id": model_row.upstream_provider_id,
"request_bytes": request_size,
},
)
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {provider.api_key}",
+74 -37
View File
@@ -28,6 +28,7 @@ from .payment.helpers import (
from .payment.models import Model
from .upstream import BaseUpstreamProvider
from .upstream.helpers import init_upstreams
from .upstream.request_correction import correct_request, extract_error_message
logger = get_logger(__name__)
proxy_router = APIRouter()
@@ -352,50 +353,86 @@ async def proxy(
if request_body_dict:
await pay_for_request(key, max_cost_for_model, session)
# Tracks request params already removed in response to upstream rejections,
# shared across providers so a stripped param stays stripped on failover and
# the reactive retry can never loop unboundedly.
already_stripped: set[str] = set()
for i, upstream in enumerate(upstreams):
headers = upstream.prepare_headers(dict(request.headers))
try:
try:
if is_responses_api:
response = await upstream.forward_responses_request(
request,
path,
headers,
request_body,
key,
max_cost_for_model,
session,
model_obj,
while True:
try:
if is_responses_api:
response = await upstream.forward_responses_request(
request,
path,
headers,
request_body,
key,
max_cost_for_model,
session,
model_obj,
)
else:
response = await upstream.forward_request(
request,
path,
headers,
request_body,
key,
max_cost_for_model,
session,
model_obj,
)
except UpstreamError:
# Let the outer UpstreamError handler manage retry/revert
raise
except Exception as e:
# Unexpected error (not an upstream failure) — revert and propagate
logger.error(
"Unexpected error in upstream request, reverting payment",
extra={
"error": str(e),
"error_type": type(e).__name__,
"path": path,
"key_hash": key.hashed_key[:8] + "...",
"max_cost_for_model": max_cost_for_model,
},
)
else:
response = await upstream.forward_request(
request,
path,
headers,
await revert_pay_for_request(key, session, max_cost_for_model)
raise
# Reactive recovery: some models reject one specific request
# param (e.g. newer Anthropic models deprecating `temperature`).
# When the upstream 400s naming such a param, strip it from the
# body and retry the SAME upstream. ``already_stripped`` bounds
# this to one retry per distinct param so it always terminates.
if response.status_code == 400:
correction = correct_request(
request_body,
key,
max_cost_for_model,
session,
model_obj,
extract_error_message(response),
already_stripped,
)
except UpstreamError:
# Let the outer UpstreamError handler manage retry/revert
raise
except Exception as e:
# Unexpected error (not an upstream failure) — revert and propagate
logger.error(
"Unexpected error in upstream request, reverting payment",
extra={
"error": str(e),
"error_type": type(e).__name__,
"path": path,
"key_hash": key.hashed_key[:8] + "...",
"max_cost_for_model": max_cost_for_model,
},
)
await revert_pay_for_request(key, session, max_cost_for_model)
raise
if correction is not None:
request_body, bad_param = correction.body, correction.label
already_stripped.add(bad_param)
logger.warning(
"Upstream %s rejected param '%s' for model=%s; "
"stripping and retrying same upstream",
upstream.provider_type,
bad_param,
model_id,
extra={
"provider": upstream.provider_type,
"model": model_id,
"stripped_param": bad_param,
"path": path,
},
)
continue
break
if response.status_code != 200:
# Check if we should retry (502 Upstream Error or 429 Rate Limit)
+142
View File
@@ -0,0 +1,142 @@
"""Reactive request-correction layer.
When an upstream rejects a request with a recoverable 4xx error, this layer
tries to *fix* the request body and let the caller retry the same upstream
instead of failing outright. It is provider-agnostic: correctors key off the
upstream's own error wording, so the same recovery works across every provider.
The layer is a small pipeline of :data:`Corrector` callables. Each corrector
inspects the parsed request body and the upstream error message and either
returns a corrected body (plus a short label identifying the fix) or declines
by returning ``None``. Adding a new reactive fix means writing one corrector
and adding it to :data:`DEFAULT_CORRECTORS` — no changes to the proxy loop.
All corrections are immutable: a corrector never mutates the body it is given,
it returns a new ``dict``. The proxy threads an ``applied`` set of fix labels
through retries so each distinct fix is applied at most once, guaranteeing the
retry loop always terminates.
"""
from __future__ import annotations
import json
import re
from collections.abc import Callable, Sequence
from dataclasses import dataclass
from fastapi.responses import Response
from ..core import get_logger
logger = get_logger(__name__)
# Matches upstream error text that names a single rejected request parameter,
# e.g. "`temperature` is deprecated for this model." or
# "parameter 'top_p' is not supported". Keys off the upstream's own wording so
# a 400 about an unsupported sampling/option field can be recovered by stripping
# that field and retrying the same upstream.
_UNSUPPORTED_PARAM_RE = re.compile(
r"[`'\"]?(?P<param>[a-zA-Z_][a-zA-Z0-9_]*)[`'\"]?\s+is\s+"
r"(?:deprecated|not\s+supported|unsupported|no\s+longer\s+supported)",
re.IGNORECASE,
)
# A corrector inspects the parsed request body and the upstream error message
# and returns ``(new_body_dict, label)`` for a fix it can apply, or ``None`` to
# decline. ``label`` identifies the fix so it is applied at most once per request.
Corrector = Callable[[dict, str], "tuple[dict, str] | None"]
@dataclass(frozen=True)
class Correction:
"""A successful request correction ready to retry.
``body`` is the corrected JSON body (encoded), ``label`` identifies the fix
that was applied (e.g. the stripped param name) so the caller can guard
against applying the same fix twice.
"""
body: bytes
label: str
def extract_error_message(response: Response) -> str:
"""Best-effort extraction of an error message string from a proxy Response."""
body_bytes = getattr(response, "body", None)
if not body_bytes:
return ""
try:
data = json.loads(body_bytes)
except Exception:
return body_bytes.decode("utf-8", errors="ignore")[:500]
if isinstance(data, dict):
err = data.get("error")
if isinstance(err, dict):
msg = err.get("message") or err.get("detail")
if isinstance(msg, str):
return msg
elif isinstance(err, str):
return err
if isinstance(data.get("message"), str):
return data["message"]
return ""
def strip_unsupported_param(
body: dict, error_message: str
) -> tuple[dict, str] | None:
"""Drop a top-level param the upstream named as unsupported/deprecated.
Returns ``(new_body, param)`` (a new dict, original untouched) when the
error names a top-level param present in the body, otherwise ``None``.
"""
match = _UNSUPPORTED_PARAM_RE.search(error_message)
if not match:
return None
param = match.group("param")
if param not in body:
return None
new_body = {k: v for k, v in body.items() if k != param}
return new_body, param
# Ordered pipeline of correctors tried on each recoverable rejection.
DEFAULT_CORRECTORS: tuple[Corrector, ...] = (strip_unsupported_param,)
def correct_request(
request_body: bytes,
error_message: str,
applied: set[str],
correctors: Sequence[Corrector] = DEFAULT_CORRECTORS,
) -> Correction | None:
"""Try to correct a rejected request body so it can be retried.
Runs each corrector in order against the parsed body and ``error_message``.
The first corrector that proposes a fix whose ``label`` is not already in
``applied`` wins; its result is returned as a :class:`Correction`. Returns
``None`` when nothing parses, nothing matches, or every proposed fix was
already applied — the caller then treats the response as a normal failure.
``applied`` is read-only here; the caller records the returned ``label`` to
bound retries and guarantee forward progress.
"""
if not request_body or not error_message:
return None
try:
data = json.loads(request_body)
except Exception:
return None
if not isinstance(data, dict):
return None
for corrector in correctors:
result = corrector(data, error_message)
if result is None:
continue
new_body, label = result
if label in applied:
continue
return Correction(body=json.dumps(new_body).encode(), label=label)
return None
@@ -0,0 +1,224 @@
import time
from types import TracebackType
from typing import Any
from unittest.mock import patch
import pytest
from httpx import AsyncClient
from routstr.core.admin import admin_sessions
from routstr.core.db import ModelRow, UpstreamProviderRow
@pytest.mark.integration
@pytest.mark.asyncio
async def test_model_test_endpoint_requires_admin_auth(
integration_client: AsyncClient,
) -> None:
with patch("httpx.AsyncClient") as mock_async_client:
response = await integration_client.post(
"/api/models/test",
json={
"model_id": "model-a",
"endpoint_type": "chat-completions",
"request_data": {"messages": []},
},
)
assert response.status_code == 403
mock_async_client.assert_not_called()
@pytest.mark.integration
@pytest.mark.asyncio
async def test_model_test_endpoint_rejects_unsupported_endpoint_type(
integration_client: AsyncClient,
integration_session: Any,
) -> None:
admin_token = "test-admin-token-model-test"
admin_sessions[admin_token] = int(time.time()) + 3600
integration_client.headers["Authorization"] = f"Bearer {admin_token}"
provider = UpstreamProviderRow(
provider_type="custom",
base_url="https://api.example.com/v1",
api_key="sk-upstream-test",
enabled=True,
provider_fee=1.01,
)
integration_session.add(provider)
await integration_session.commit()
await integration_session.refresh(provider)
assert provider.id is not None
model = ModelRow(
id="model-a",
name="Model A",
created=1,
description="desc",
context_length=100,
architecture='{"modality": "text", "input_modalities": ["text"], "output_modalities": ["text"], "tokenizer": "tiktoken", "instruct_type": "chat"}',
pricing='{"prompt": 1.0, "completion": 1.0}',
upstream_provider_id=provider.id,
enabled=True,
)
integration_session.add(model)
await integration_session.commit()
try:
with patch("httpx.AsyncClient") as mock_async_client:
response = await integration_client.post(
"/api/models/test",
json={
"model_id": "model-a",
"endpoint_type": "../../abuse",
"request_data": {"messages": []},
},
)
assert response.status_code == 400
assert response.json()["detail"] == "Unsupported endpoint_type"
mock_async_client.assert_not_called()
finally:
admin_sessions.pop(admin_token, None)
@pytest.mark.integration
@pytest.mark.asyncio
async def test_model_test_endpoint_rejects_oversized_request_data(
integration_client: AsyncClient,
integration_session: Any,
) -> None:
admin_token = "test-admin-token-model-test-oversized"
admin_sessions[admin_token] = int(time.time()) + 3600
integration_client.headers["Authorization"] = f"Bearer {admin_token}"
provider = UpstreamProviderRow(
provider_type="custom",
base_url="https://api.example.com/v1",
api_key="sk-upstream-test",
enabled=True,
provider_fee=1.01,
)
integration_session.add(provider)
await integration_session.commit()
await integration_session.refresh(provider)
assert provider.id is not None
model = ModelRow(
id="model-a",
name="Model A",
created=1,
description="desc",
context_length=100,
architecture='{"modality": "text", "input_modalities": ["text"], "output_modalities": ["text"], "tokenizer": "tiktoken", "instruct_type": "chat"}',
pricing='{"prompt": 1.0, "completion": 1.0}',
upstream_provider_id=provider.id,
enabled=True,
)
integration_session.add(model)
await integration_session.commit()
oversized = "x" * (64 * 1024 + 1)
try:
with patch("httpx.AsyncClient") as mock_async_client:
response = await integration_client.post(
"/api/models/test",
json={
"model_id": "model-a",
"endpoint_type": "chat-completions",
"request_data": {"blob": oversized},
},
)
assert response.status_code == 413
assert response.json()["detail"] == "request_data too large"
mock_async_client.assert_not_called()
finally:
admin_sessions.pop(admin_token, None)
@pytest.mark.integration
@pytest.mark.asyncio
async def test_model_test_endpoint_admin_uses_allowed_upstream_path(
integration_client: AsyncClient,
integration_session: Any,
) -> None:
admin_token = "test-admin-token-model-test-success"
admin_sessions[admin_token] = int(time.time()) + 3600
integration_client.headers["Authorization"] = f"Bearer {admin_token}"
provider = UpstreamProviderRow(
provider_type="custom",
base_url="https://api.example.com/v1",
api_key="sk-upstream-test",
enabled=True,
provider_fee=1.01,
)
integration_session.add(provider)
await integration_session.commit()
await integration_session.refresh(provider)
assert provider.id is not None
model = ModelRow(
id="model-a",
name="Model A",
created=1,
description="desc",
context_length=100,
architecture='{"modality": "text", "input_modalities": ["text"], "output_modalities": ["text"], "tokenizer": "tiktoken", "instruct_type": "chat"}',
pricing='{"prompt": 1.0, "completion": 1.0}',
upstream_provider_id=provider.id,
enabled=True,
forwarded_model_id="upstream-model-a",
)
integration_session.add(model)
await integration_session.commit()
class MockResponse:
status_code = 200
text = '{"ok": true}'
def json(self) -> dict[str, bool]:
return {"ok": True}
class MockAsyncClient:
async def __aenter__(self) -> "MockAsyncClient":
return self
async def __aexit__(
self,
exc_type: type[BaseException] | None,
exc: BaseException | None,
tb: TracebackType | None,
) -> None:
return None
async def post(
self, url: str, json: dict[str, Any], headers: dict[str, str]
) -> MockResponse:
assert url == "https://api.example.com/v1/chat/completions"
assert json["model"] == "upstream-model-a"
assert headers["Authorization"] == "Bearer sk-upstream-test"
return MockResponse()
try:
with patch("httpx.AsyncClient", return_value=MockAsyncClient()):
response = await integration_client.post(
"/api/models/test",
json={
"model_id": "model-a",
"endpoint_type": "chat-completions",
"request_data": {"messages": []},
},
)
assert response.status_code == 200
assert response.json() == {
"success": True,
"data": {"ok": True},
"status_code": 200,
}
finally:
admin_sessions.pop(admin_token, None)
+156
View File
@@ -0,0 +1,156 @@
"""Unit tests for the reactive request-correction layer.
Covers the recovery path that lets a request survive a 400 where the upstream
names a single unsupported request param (e.g. newer Anthropic models
deprecating ``temperature``): the param is stripped from the JSON body and the
same upstream is retried, provider-agnostically, keyed off the error text.
"""
from __future__ import annotations
import json
from fastapi.responses import Response
from routstr.upstream.request_correction import (
Correction,
correct_request,
extract_error_message,
strip_unsupported_param,
)
def _body(**kwargs: object) -> bytes:
return json.dumps(kwargs).encode()
class TestCorrectRequest:
def test_strips_deprecated_temperature(self) -> None:
body = _body(model="claude-opus-4-8", temperature=1, messages=[])
result = correct_request(
body, "`temperature` is deprecated for this model.", set()
)
assert isinstance(result, Correction)
assert result.label == "temperature"
decoded = json.loads(result.body)
assert "temperature" not in decoded
assert decoded["model"] == "claude-opus-4-8"
def test_strips_not_supported_param(self) -> None:
body = _body(model="m", top_p=0.9, messages=[])
result = correct_request(body, "Parameter 'top_p' is not supported", set())
assert result is not None
assert result.label == "top_p"
assert "top_p" not in json.loads(result.body)
def test_returns_none_when_label_already_applied(self) -> None:
body = _body(model="m", temperature=1)
assert (
correct_request(body, "`temperature` is deprecated", {"temperature"})
is None
)
def test_returns_none_when_param_absent_from_body(self) -> None:
body = _body(model="m", messages=[])
assert correct_request(body, "`temperature` is deprecated", set()) is None
def test_returns_none_when_message_does_not_match(self) -> None:
body = _body(model="m", temperature=1)
assert correct_request(body, "Insufficient balance", set()) is None
def test_returns_none_on_empty_inputs(self) -> None:
assert correct_request(b"", "`temperature` is deprecated", set()) is None
assert correct_request(_body(temperature=1), "", set()) is None
def test_returns_none_on_non_object_body(self) -> None:
assert correct_request(b"[1, 2, 3]", "`temperature` is deprecated", set()) is None
def test_deprecated_model_name_is_not_stripped_as_param(self) -> None:
"""A 'model is deprecated' error must not strip an unrelated body field.
The regex matches the ``<token> is deprecated`` wording, but the
``param not in body`` guard means a deprecated *model* name (not a
request param) yields no correction rather than a false strip.
"""
body = _body(model="gpt-3", temperature=1, messages=[])
assert correct_request(body, "`gpt-3` is deprecated, use gpt-4", set()) is None
def test_streaming_400_buffered_error_is_correctable(self) -> None:
"""Streaming 400s funnel through a buffered JSON Response, so the same
correction path applies as for non-streaming requests."""
# Mirrors forward_upstream_error_response's buffered JSON envelope.
resp = Response(
content=json.dumps(
{"error": {"message": "`temperature` is deprecated for this model"}}
).encode(),
status_code=400,
)
body = _body(model="claude-opus-4-8", temperature=1, messages=[])
result = correct_request(body, extract_error_message(resp), set())
assert isinstance(result, Correction)
assert result.label == "temperature"
assert "temperature" not in json.loads(result.body)
class TestStripUnsupportedParam:
def test_does_not_mutate_input(self) -> None:
body = {"model": "m", "temperature": 1}
result = strip_unsupported_param(body, "`temperature` is deprecated")
assert result is not None
new_body, param = result
assert param == "temperature"
assert "temperature" not in new_body
# original untouched (immutability)
assert body == {"model": "m", "temperature": 1}
def test_declines_when_no_match(self) -> None:
assert strip_unsupported_param({"temperature": 1}, "nope") is None
class TestExtractErrorMessage:
def test_extracts_nested_error_message(self) -> None:
resp = Response(
content=json.dumps(
{"error": {"message": "`temperature` is deprecated", "type": "x"}}
).encode(),
status_code=400,
)
assert extract_error_message(resp) == "`temperature` is deprecated"
def test_extracts_string_error(self) -> None:
resp = Response(
content=json.dumps({"error": "bad request"}).encode(), status_code=400
)
assert extract_error_message(resp) == "bad request"
def test_extracts_top_level_message(self) -> None:
resp = Response(
content=json.dumps({"message": "nope"}).encode(), status_code=400
)
assert extract_error_message(resp) == "nope"
def test_empty_body_returns_empty_string(self) -> None:
assert extract_error_message(Response(status_code=400)) == ""
def test_non_json_body_returns_preview(self) -> None:
resp = Response(content=b"plain text error", status_code=400)
assert extract_error_message(resp) == "plain text error"
class TestEndToEndChaining:
def test_two_distinct_params_corrected_sequentially(self) -> None:
"""Simulates the proxy loop: each 400 fixes one param, set guards reuse."""
body = _body(model="m", temperature=1, top_p=0.5, messages=[])
applied: set[str] = set()
first = correct_request(body, "`temperature` is deprecated", applied)
assert first is not None
body, applied = first.body, applied | {first.label}
second = correct_request(body, "`top_p` is not supported", applied)
assert second is not None
body, applied = second.body, applied | {second.label}
decoded = json.loads(body)
assert "temperature" not in decoded and "top_p" not in decoded
assert applied == {"temperature", "top_p"}