headroom/tests/test_proxy/test_anthropic_buffered_timeout.py
Abhay Singh 2b5ee7cde8
fix(proxy/anthropic): None-guard usage token counts on the direct buffered path (#2434)
## Description

The direct (non-backend) Anthropic buffered `/v1/messages` path reads
token counts from the response usage to record metrics and update the
prefix tracker:

```python
usage = resp_json.get("usage", {})
output_tokens = usage.get("output_tokens", 0)
cr_tokens = usage.get("cache_read_input_tokens", 0)
cw_tokens = usage.get("cache_creation_input_tokens", 0)
...
uncached_input_tokens = usage.get("input_tokens", 0)
```

`.get(key, default)` only falls back when the key is **absent**. When a
key is present with a **null** value, `.get` returns `None`. The direct
Anthropic API always sends integer usage, but this same handler serves
any Anthropic-compatible upstream reached through a custom
`ANTHROPIC_TARGET_API_URL` gateway (the scenario `install apply` now
supports), and such a gateway can emit null counts on a stopped or empty
turn.

Those `None`s then reach `max(0, expected_cached - cr_tokens)` in the
cache-bust block and the int-typed `RequestOutcome` / metrics recorder,
so a single such response raises an uncaught `TypeError` and 502s the
request. This is the same class as the Gemini crash fixed in #2347 and
the OpenAI chat path.

## Fix

Coerce the four counts with `int(... or 0)` at the direct-path
usage-extraction site, matching `_extract_anthropic_cache_ttl_metrics`
(which already guards its TTL buckets this way) and the Gemini fix. A
normal integer usage is unchanged; only a null (or absent) value now
becomes 0.

## Type of Change

- [x] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [ ] Code refactoring (no functional changes)

## Changes Made

- `headroom/proxy/handlers/anthropic.py`: `int(... or 0)`-guard
`output_tokens` / `cache_read_input_tokens` /
`cache_creation_input_tokens` / `input_tokens` at the direct
buffered-path usage-extraction site.
- `tests/test_proxy/test_anthropic_buffered_timeout.py`: regression
driving a buffered `/v1/messages` request whose upstream usage reports
null counts, asserting a 200 instead of a 502.

## Testing

- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [x] Type checking passes (`mypy headroom`)
- [x] New tests added for new functionality
- [ ] Manual testing performed

### Test Output

```text
$ python -m pytest tests/test_proxy/test_anthropic_buffered_timeout.py -q
# all pass

# with the fix reverted, the new test fails (the null-usage response 502s):
$ git stash push -- headroom/proxy/handlers/anthropic.py
$ python -m pytest "tests/test_proxy/test_anthropic_buffered_timeout.py::test_anthropic_messages_buffered_survives_null_usage_counts" -q
1 failed  (TypeError: unsupported operand type(s) for +: 'NoneType' and 'NoneType')

$ uvx ruff@0.15.17 check headroom/proxy/handlers/anthropic.py tests/test_proxy/test_anthropic_buffered_timeout.py
All checks passed!
```

## Real Behavior Proof

- Environment: Windows 11, Python 3.12, project venv (`uv sync --extra
proxy`), `uvx ruff@0.15.17` / `uvx mypy@1.20.2`, pytest in the venv.
- Exact command / steps: ran the new FastAPI `TestClient` regression,
which drives the real direct buffered `/v1/messages` handler with
`proxy._retry_request` returning a 200 whose `usage` has null
`input_tokens` / `output_tokens` / `cache_read_input_tokens` /
`cache_creation_input_tokens`; then reverted only `anthropic.py` and
re-ran.
- Observed result: with the fix the request returns 200; with the fix
reverted the same request 502s with `TypeError: unsupported operand
type(s) for +: 'NoneType' and 'NoneType'`. Ran against the actual
handler via the app.
- Not tested: a live third-party Anthropic-compatible gateway emitting
null usage.

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] I have updated the CHANGELOG.md if applicable

Co-authored-by: JerrettDavis <mxjerrett@gmail.com>
2026-08-12 00:07:51 -05:00

465 lines
15 KiB
Python

from __future__ import annotations
import pytest
fastapi = pytest.importorskip("fastapi")
httpx = pytest.importorskip("httpx")
from fastapi.testclient import TestClient # noqa: E402
from headroom.proxy.server import ProxyConfig, create_app # noqa: E402
class _FakePrefixTracker:
def get_frozen_message_count(self) -> int:
return 0
def get_last_original_messages(self) -> list[dict]:
return []
def get_last_forwarded_messages(self) -> list[dict]:
return []
def update_from_response(self, **kwargs): # noqa: ANN003
return None
class _BufferedPassthroughClient:
def __init__(self, response: httpx.Response) -> None:
self.response = response
self.calls: list[dict[str, object]] = []
async def request(self, method, url, headers=None, content=None, timeout=None): # noqa: ANN001
self.calls.append(
{
"method": method,
"url": url,
"headers": headers,
"content": content,
"timeout": timeout,
}
)
_assert_buffered_timeout(timeout)
return self.response
async def get(self, url, headers=None, timeout=None): # noqa: ANN001
return await self.request("GET", url, headers=headers, timeout=timeout)
async def post(self, url, headers=None, content=None, timeout=None): # noqa: ANN001
return await self.request("POST", url, headers=headers, content=content, timeout=timeout)
async def aclose(self) -> None:
return None
def _assert_buffered_timeout(timeout: httpx.Timeout | None) -> None:
assert isinstance(timeout, httpx.Timeout)
assert timeout.connect == 3.0
assert timeout.read == 19.0
assert timeout.write == 7.0
assert timeout.pool == 3.0
def _make_config() -> ProxyConfig:
return ProxyConfig(
optimize=False,
cache_enabled=False,
rate_limit_enabled=False,
cost_tracking_enabled=False,
log_requests=False,
ccr_inject_tool=False,
ccr_handle_responses=False,
ccr_context_tracking=False,
image_optimize=False,
connect_timeout_seconds=3,
request_timeout_seconds=7,
anthropic_buffered_request_timeout_seconds=19,
)
def _install_prefix_tracker(proxy) -> None:
tracker = _FakePrefixTracker()
proxy.session_tracker_store.compute_session_id = lambda request, model, messages: "s1"
proxy.session_tracker_store.get_or_create = lambda session_id, provider: tracker
def _anthropic_message_response() -> dict[str, object]:
return {
"id": "msg_test_1",
"type": "message",
"role": "assistant",
"content": [{"type": "text", "text": "ok"}],
"usage": {
"input_tokens": 12,
"output_tokens": 3,
"cache_read_input_tokens": 0,
"cache_creation_input_tokens": 0,
},
}
def _anthropic_batch_response() -> dict[str, object]:
return {"id": "batch_test_1", "object": "batch", "status": "in_progress"}
def _anthropic_list_response() -> httpx.Response:
return httpx.Response(
200,
json={"object": "list", "data": [], "first_id": None, "last_id": None},
headers={"content-type": "application/json"},
)
def _anthropic_null_usage_response() -> dict[str, object]:
"""An Anthropic Messages response whose usage counts are present but null.
An Anthropic-compatible gateway (custom ANTHROPIC_TARGET_API_URL) can emit
this shape on a stopped or empty turn — the same class that crashed the
Gemini path in #2347.
"""
return {
"id": "msg_test_null",
"type": "message",
"role": "assistant",
"content": [{"type": "text", "text": "ok"}],
"usage": {
"input_tokens": None,
"output_tokens": None,
"cache_read_input_tokens": None,
"cache_creation_input_tokens": None,
},
}
def test_anthropic_messages_buffered_survives_null_usage_counts():
config = _make_config()
app = create_app(config)
with TestClient(app) as client:
proxy = client.app.state.proxy
# Use the real prefix tracker (its `_cached_token_count` is read on this
# path); only pin the session id so the tracker resolves deterministically.
proxy.session_tracker_store.compute_session_id = lambda request, model, messages: "s1"
async def _fake_retry(method, url, headers, body, stream=False, **kwargs): # noqa: ANN001
return httpx.Response(200, json=_anthropic_null_usage_response())
proxy._retry_request = _fake_retry # type: ignore[assignment]
response = client.post(
"/v1/messages",
headers={
"x-api-key": "test-key",
"anthropic-version": "2023-06-01",
"content-type": "application/json",
},
json={
"model": "claude-sonnet-4-6",
"max_tokens": 64,
"messages": [{"role": "user", "content": "hello"}],
},
)
# Null usage counts must not crash outcome recording / cache-bust math.
assert response.status_code == 200, response.text
def test_anthropic_messages_buffered_timeout_override_reaches_retry_request():
config = _make_config()
app = create_app(config)
with TestClient(app) as client:
proxy = client.app.state.proxy
_install_prefix_tracker(proxy)
captured: dict[str, object] = {}
async def _fake_retry(method, url, headers, body, stream=False, **kwargs): # noqa: ANN001
timeout = kwargs.get("timeout")
captured["timeout"] = timeout
_assert_buffered_timeout(timeout)
return httpx.Response(200, json=_anthropic_message_response())
proxy._retry_request = _fake_retry # type: ignore[assignment]
response = client.post(
"/v1/messages",
headers={
"x-api-key": "test-key",
"anthropic-version": "2023-06-01",
"content-type": "application/json",
},
json={
"model": "claude-sonnet-4-6",
"max_tokens": 64,
"messages": [{"role": "user", "content": "hello"}],
},
)
assert "timeout" in captured, response.text
assert isinstance(captured["timeout"], httpx.Timeout)
def test_anthropic_batch_create_buffered_timeout_override_reaches_retry_request():
config = _make_config()
app = create_app(config)
with TestClient(app) as client:
proxy = client.app.state.proxy
captured: dict[str, object] = {}
async def _fake_retry(method, url, headers, body, stream=False, **kwargs): # noqa: ANN001
timeout = kwargs.get("timeout")
captured["timeout"] = timeout
_assert_buffered_timeout(timeout)
return httpx.Response(200, json=_anthropic_batch_response())
proxy._retry_request = _fake_retry # type: ignore[assignment]
response = client.post(
"/v1/messages/batches",
headers={
"x-api-key": "test-key",
"anthropic-version": "2023-06-01",
"content-type": "application/json",
},
json={
"requests": [
{
"custom_id": "req-1",
"params": {
"model": "claude-sonnet-4-6",
"max_tokens": 64,
"messages": [{"role": "user", "content": "hello"}],
},
}
]
},
)
assert response.status_code == 200, response.text
assert isinstance(captured["timeout"], httpx.Timeout)
def test_anthropic_batch_passthrough_buffered_timeout_override_reaches_http_client():
config = _make_config()
app = create_app(config)
with TestClient(app) as client:
proxy = client.app.state.proxy
http_client = _BufferedPassthroughClient(_anthropic_list_response())
proxy.http_client = http_client
response = client.get(
"/v1/messages/batches",
headers={
"x-api-key": "test-key",
"anthropic-version": "2023-06-01",
},
)
assert response.status_code == 200, response.text
assert len(http_client.calls) == 1
assert isinstance(http_client.calls[0]["timeout"], httpx.Timeout)
def test_anthropic_batch_results_buffered_timeout_override_reaches_http_client_get():
config = _make_config()
app = create_app(config)
with TestClient(app) as client:
proxy = client.app.state.proxy
http_client = _BufferedPassthroughClient(
httpx.Response(
200,
content=b'{"custom_id":"req-1","result":{"type":"succeeded"}}\n',
headers={"content-type": "application/jsonl"},
)
)
proxy.http_client = http_client
response = client.get(
"/v1/messages/batches/batch_test_1/results",
headers={
"x-api-key": "test-key",
"anthropic-version": "2023-06-01",
},
)
assert response.status_code == 200, response.text
assert len(http_client.calls) == 1
assert http_client.calls[0]["method"] == "GET"
assert isinstance(http_client.calls[0]["timeout"], httpx.Timeout)
def test_anthropic_ccr_continuation_uses_buffered_timeout() -> None:
config = _make_config()
config.ccr_inject_tool = True
config.ccr_handle_responses = True
app = create_app(config)
class _CCRHandler:
def has_ccr_tool_calls(self, response, provider): # noqa: ANN001
return True
async def handle_response( # noqa: ANN001
self,
response,
optimized_messages,
tools,
api_call_fn,
provider,
):
return await api_call_fn(
optimized_messages
+ [{"role": "assistant", "content": response.get("content", [])}],
tools,
)
with TestClient(app) as client:
proxy = client.app.state.proxy
_install_prefix_tracker(proxy)
proxy.ccr_response_handler = _CCRHandler()
http_client = _BufferedPassthroughClient(
httpx.Response(200, json=_anthropic_message_response())
)
proxy.http_client = http_client
async def _fake_retry(method, url, headers, body, stream=False, **kwargs): # noqa: ANN001
return httpx.Response(200, json=_anthropic_message_response())
proxy._retry_request = _fake_retry # type: ignore[assignment]
client.post(
"/v1/messages",
headers={
"x-api-key": "test-key",
"anthropic-version": "2023-06-01",
"content-type": "application/json",
},
json={
"model": "claude-sonnet-4-6",
"max_tokens": 64,
"messages": [{"role": "user", "content": "hello"}],
},
)
assert len(http_client.calls) == 1
assert http_client.calls[0]["method"] == "POST"
assert isinstance(http_client.calls[0]["timeout"], httpx.Timeout)
def test_anthropic_memory_continuation_uses_buffered_timeout() -> None:
config = _make_config()
config.memory_enabled = True
app = create_app(config)
class _MemoryHandler:
def __init__(self) -> None:
self.config = type(
"MemoryConfig",
(),
{
"inject_context": False,
"inject_tools": False,
"project_root_override": "",
},
)()
self.initialized = False
self.backend = None
def get_beta_headers(self) -> dict[str, str]:
return {}
def has_memory_tool_calls(self, response, provider): # noqa: ANN001
return True
async def handle_memory_tool_calls( # noqa: ANN001
self,
response,
user_id,
provider,
**kwargs,
):
return [{"type": "tool_result", "tool_use_id": "mem_1", "content": "memory"}]
with TestClient(app) as client:
proxy = client.app.state.proxy
_install_prefix_tracker(proxy)
proxy.memory_handler = _MemoryHandler()
captured_timeouts: list[httpx.Timeout | None] = []
async def _fake_retry(method, url, headers, body, stream=False, **kwargs): # noqa: ANN001
timeout = kwargs.get("timeout")
captured_timeouts.append(timeout)
if len(body["messages"]) > 1:
_assert_buffered_timeout(timeout)
return httpx.Response(200, json=_anthropic_message_response())
proxy._retry_request = _fake_retry # type: ignore[assignment]
client.post(
"/v1/messages",
headers={
"x-api-key": "test-key",
"anthropic-version": "2023-06-01",
"content-type": "application/json",
"x-headroom-user-id": "user-1",
},
json={
"model": "claude-sonnet-4-6",
"max_tokens": 64,
"messages": [{"role": "user", "content": "hello"}],
},
)
assert len(captured_timeouts) == 2
assert all(isinstance(timeout, httpx.Timeout) for timeout in captured_timeouts)
def test_retry_request_without_override_uses_client_default_timeout():
config = _make_config()
app = create_app(config)
with TestClient(app) as client:
proxy = client.app.state.proxy
captured: list[dict[str, object]] = []
async def _fake_retry(method, url, headers, body, stream=False, **kwargs): # noqa: ANN001
captured.append(kwargs)
return httpx.Response(
200,
json={
"id": "chatcmpl-1",
"object": "chat.completion",
"choices": [
{
"index": 0,
"message": {"role": "assistant", "content": "ok"},
"finish_reason": "stop",
}
],
"usage": {"prompt_tokens": 5, "completion_tokens": 1, "total_tokens": 6},
},
)
proxy._retry_request = _fake_retry # type: ignore[assignment]
response = client.post(
"/v1/chat/completions",
headers={"authorization": "Bearer test-key", "content-type": "application/json"},
json={
"model": "gpt-4o",
"messages": [{"role": "user", "content": "hello"}],
},
)
assert response.status_code == 200, response.text
assert len(captured) == 1
assert "timeout" not in captured[0], (
"_retry_request without an override must not pass timeout=None to httpx"
)
def test_generic_proxy_timeout_defaults_stay_unchanged():
app = create_app(ProxyConfig())
with TestClient(app) as client:
timeout = client.app.state.proxy.http_client.timeout
assert timeout.connect == 10.0
assert timeout.read == 300.0
assert timeout.write == 300.0
assert timeout.pool == 10.0