headroom/tests/conftest.py
Tejas Chopra 9cfb00838a
fix(telemetry): anonymous compression stats — no prompts, no data (#2728)
## In one line

Headroom starts reporting **how well compression is working** — counters
and percentages only. **No prompts. No code. No file paths. Nothing
about what you're building.**

## Why

Right now nobody knows whether compression actually helps real users.
You can see your own numbers in `/stats`, but that's it — there's no way
to tell whether a given workload compresses well, or why it sometimes
doesn't. This closes that loop so we can make compression better for
everyone.

## Exactly what gets sent

One message per session, and every 5 minutes while you're active:

```json
{
  "session":     { "id": "random", "turns": 47, "duration_s": 4210, "seq": 3 },
  "tokens":      { "original": 890000, "attempted": 410000, "saved": 320000,
                   "tool_saved": 48000, "cache_read": 210000 },
  "rates":       { "saved_pct": 35.96, "eligible_pct": 46.07, "yield_pct": 78.05,
                   "cache_read_pct": 23.60, "overhead_pct": 1.96 },
  "compression": { "transforms": {"crush": 47}, "passthrough_turns": 0 },
  "skips":       {},
  "sources":     { "proxy": 47 },
  "providers":   ["anthropic"],
  "models":      ["claude-sonnet-4-5-20250929"],
  "failures":    2
}
```

Plus a random install ID, the Headroom version, and OS/architecture
(`darwin`, `arm64`).

That's the whole thing. A full example lives at
`deploy/beacon/sample-event.json`.

## What is never sent

- Your prompts or the model's responses
- Your code
- File paths, project names, repo names
- Tool names or MCP server names
- Hostname, username, or IP address
- Custom or fine-tuned model names (an id like `ft:gpt-4o:acme-corp:…`
contains a company name, so only models in a public registry are
reported)

**This is structural, not a pinky-swear.** Every value in the payload is
a number, a fixed word, or a random ID — there is no free-text field
anywhere for content to hide in. The receiver
(`deploy/beacon/worker.js`, in this repo so you can read it) drops
anything not on an explicit allowlist before storing.

## Turning it off

Any one of these:

```bash
HEADROOM_BEACON=off      # or
DO_NOT_TRACK=1           # or
# offline mode
```

It's on by default, and Headroom says so at startup:

```
Telemetry:    anonymous compression stats — never prompts, code, or file paths.
              Helps us improve compression | Off: HEADROOM_BEACON=off
```

`HEADROOM_TELEMETRY` is a **separate** switch that still only affects
local stats. If you had turned that on, this change does not start
uploading anything — you answered a different question, and upgrading
should not change the answer.

## Why the percentages, not just "tokens saved"

"We saved 36%" hides the interesting part. In the example above only
**46% of tokens were eligible** for compression at all — the rest is
frozen cache prefix and system prompts we deliberately do not touch. Of
what we *could* touch, we removed **78%**.

Those are two separate problems. Raising eligibility is proxy work;
raising yield is compressor work. A single number cannot tell us which
to fix.

## Coverage

`emit_request_outcome` is a single chokepoint —
`handler.metrics.record_request` is called from exactly one place,
inside the funnel — so all 30 `RequestOutcome` construction sites are
covered: Anthropic, OpenAI, Gemini, Bedrock, batch, streaming, and the
long-lived Codex Responses-WS path.

The `headroom_compress` MCP path bypassed that funnel and is now wired
in separately. It has a different shape (no provider, no upstream
latency, and everything handed to the tool is eligible by construction),
so `sources` counts turns by origin — MCP turns always read
`eligible_pct: 100` and must not drag the proxy's real eligibility
ceiling upward.

**Subagents.** All subagent traffic through the proxy merges into one
session, which is correct for savings and retention but means `turns`
conflates fan-out with depth. Fan-out is still derivable —
`compression.latency_ms_total / session.duration_s` gives the
concurrency ratio (~1x serial, ~4x for four parallel agents), so no
extra field is needed. Verified no lost updates under 6-way concurrency
(1,200 turns).

**Known gap:** `--workers N` gives each process its own aggregator, so
one user session becomes up to N. Token totals and fleet rates stay
correct; session counts inflate. This matches the existing documented
limitation that TOIN state, CostTracker, and the prefix tracker are all
per-process.

## Notes for reviewers

- **Cumulative snapshots, not deltas.** Every report restates running
totals under one session ID, so the highest `seq` per `(install,
session)` is the complete session. Dedupe is a window function, and a
lost report costs nothing.
- **Never breaks the proxy.** Every path swallows its own exceptions;
uploads go out on a daemon thread so nothing blocks the request loop.
- **Explicit User-Agent is load-bearing.** urllib's default is blocked
by Cloudflare (error 1010). Combined with fire-and-forget error
handling, that would have failed every upload while looking perfectly
healthy.
- **The exit flush was broken and is fixed.** `atexit` handed the POST
to a daemon thread, and daemon threads are killed before they finish
during interpreter shutdown — so nothing was sent. That silently dropped
*every session shorter than the 5-minute heartbeat*, plus all
short-lived subagent MCP processes. The exit path now posts
synchronously with a 2s timeout.
- Receiver and query tooling are in `deploy/beacon/`.

## Testing

- `python -m headroom.telemetry.session` self-check: dedupe, cumulative
totals, dropped-report recovery, payload contains no model id or
prompt-derived string, allowlist coverage
- 175 telemetry/outcome tests pass; 6 new ones cover the opt-out notice
- Verified end to end against a live deployment: client → receiver →
storage → query

## Still to do before release

The default endpoint currently points at a temporary `workers.dev` URL.
It needs to move to a Headroom-owned hostname before this ships in a
tagged release — noted inline at `DEFAULT_ENDPOINT`.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-03 05:43:25 -07:00

353 lines
12 KiB
Python

"""Shared pytest fixtures for Headroom tests."""
# CRITICAL: Must be set before ANY imports that could trigger sentence_transformers
# The Rust tokenizers use parallelism that deadlocks with pytest-asyncio
import os
os.environ["TOKENIZERS_PARALLELISM"] = "false"
import json
import tempfile
from datetime import datetime
from pathlib import Path
from unittest.mock import Mock
import pytest
from tests._skip_helpers import external_model_skip_reason
# A live `headroom` dev session exports HEADROOM_* into the shell (and the
# Claude wrap adds ANTHROPIC_CUSTOM_HEADERS). Click `envvar=` options pick
# those up inside CliRunner, so assertions would see the developer's proxy
# config instead of the test's. Scrub them so local runs match CI; tests
# that need a value set it explicitly via monkeypatch or CliRunner env.
@pytest.fixture(autouse=True)
def _scrub_developer_headroom_env(monkeypatch):
for key in list(os.environ):
if key.startswith("HEADROOM_"):
monkeypatch.delenv(key, raising=False)
monkeypatch.delenv("ANTHROPIC_CUSTOM_HEADERS", raising=False)
# The scrub above deletes every HEADROOM_* var — which includes HEADROOM_BEACON,
# and the beacon defaults to ON. So scrubbing for hermeticity is precisely what
# switches it on, and with HEADROOM_TELEMETRY_ENDPOINT scrubbed too it falls back
# to the real production endpoint. Every test that reaches the outcome funnel
# then POSTs a session event for real: observed writing into the live corpus
# during a local run, and CI would do the same on every push.
#
# Depends on the scrub fixture so it is guaranteed to run after it rather than
# relying on declaration order. A test that wants the beacon on just sets the
# var itself — monkeypatch inside the test wins over this.
@pytest.fixture(autouse=True)
def _disable_telemetry_beacon(monkeypatch, _scrub_developer_headroom_env):
monkeypatch.setenv("HEADROOM_BEACON", "off")
# The MCP install ledger defaults to ``~/.headroom/mcp_installs.json``, so any
# test that registers a server (directly or through `wrap`) writes into the
# developer's REAL ledger — observed adding a live `claude/serena` entry during a
# local run. Since the scrub above deletes HEADROOM_WORKSPACE_DIR, the default is
# always the real home. Redirect the ledger per-test instead: every writer
# (`record_install` / `clear_install` / `headroom_installed_matching`) resolves it
# through this module-global, so one patch covers them all. Patched here rather
# than pointing workspace_dir() at a tmp path, which would break the tests that
# assert the default workspace layout.
@pytest.fixture(autouse=True)
def _isolate_mcp_ledger(monkeypatch, tmp_path_factory):
# Same guard as _reset_copilot_routing_flag below: the macos/windows-native-
# wrapper CI jobs install only pytest and drive the installer shell scripts
# via subprocess, so headroom isn't importable and there is no ledger to
# redirect. Skip there instead of erroring at setup.
try:
from headroom.mcp_registry import ledger
except ModuleNotFoundError:
return
ledger_file = tmp_path_factory.mktemp("mcp-ledger") / "mcp_installs.json"
monkeypatch.setattr(ledger, "ledger_path", lambda: ledger_file)
# The Copilot "routed to Copilot" flag is a module-global ContextVar that
# build_copilot_upstream_url() sets as a side effect. Unit tests that call that
# builder directly (or otherwise run in the shared root context) would leave it
# set and mislabel a later test's request outcome as "copilot". Reset it around
# every test so build-time side effects can't leak between tests.
@pytest.fixture(autouse=True)
def _reset_copilot_routing_flag():
# The macos/windows-native-wrapper CI jobs run the installer tests with only
# pytest installed (no headroom): they drive the installer shell scripts via
# subprocess, so headroom isn't importable and there's no routing flag to
# reset. Skip the reset there instead of erroring at setup.
try:
from headroom.copilot_auth import reset_request_routed_to_copilot
except ModuleNotFoundError:
yield
return
reset_request_routed_to_copilot()
yield
reset_request_routed_to_copilot()
# =============================================================================
# Global test hooks
# =============================================================================
@pytest.hookimpl(hookwrapper=True)
def pytest_runtest_call(item):
"""Wrap test execution to skip transient or offline external model failures.
This handles model-loading failures that occur when:
- HuggingFace Hub is slow during model downloads (sentence-transformers)
- Required HuggingFace model files were not restored into the offline CI cache
- External embedding APIs timeout
- Network connectivity issues in CI
"""
outcome = yield
if outcome.excinfo is not None:
exc_type, exc_value, exc_tb = outcome.excinfo
reason = external_model_skip_reason(exc_value)
if reason is not None:
pytest.skip(reason)
@pytest.fixture(autouse=True)
def _reset_headroom_logger_propagation():
"""Keep `headroom.*` log records flowing to pytest's caplog handler.
Two sources disable propagation on the headroom logger tree and never
restore it, which then makes later `caplog`-based assertions flaky in
full-suite runs (caplog attaches to root, so a `propagate=False` anywhere
on the chain silently drops the records):
- ``headroom.proxy.helpers._setup_file_logging`` sets
``getLogger("headroom").propagate = False`` on proxy startup.
- ``benchmarks.claude_session_mode_benchmark._disable_headroom_benchmark_logging``
(exercised by ``test_claude_session_mode_benchmark``) sets
``propagate = False`` + ``CRITICAL`` on ``headroom``, ``headroom.proxy``,
``headroom.transforms``, ``headroom.cache`` (and children).
Resetting only ``"headroom"`` is not enough — a child like
``"headroom.proxy"`` left non-propagating blocks the record before it
reaches root. Reset the whole subtree before every test so capture is
deterministic regardless of run order.
"""
import logging as _logging
for _name in ("headroom", *list(_logging.root.manager.loggerDict)):
if _name == "headroom" or _name.startswith("headroom."):
logger = _logging.getLogger(_name)
logger.disabled = False
# The benchmark also raises the level to CRITICAL; children
# inherit it (effective level), so a WARNING would be filtered
# at the logger before it can propagate to caplog. Reset to
# NOTSET so the subtree inherits root's level deterministically.
logger.setLevel(_logging.NOTSET)
logger.propagate = True
yield
# =============================================================================
# Sample messages fixtures
# =============================================================================
# Sample messages fixtures
@pytest.fixture
def sample_messages():
"""Basic conversation messages."""
return [
{"role": "system", "content": "You are a helpful assistant."},
{"role": "user", "content": "Hello, how are you?"},
{"role": "assistant", "content": "I'm doing well, thank you!"},
]
@pytest.fixture
def sample_messages_with_tools():
"""Conversation with tool calls and responses."""
return [
{"role": "system", "content": "You are a helpful assistant with tools."},
{"role": "user", "content": "Search for user 12345"},
{
"role": "assistant",
"content": None,
"tool_calls": [
{
"id": "call_123",
"type": "function",
"function": {"name": "search_user", "arguments": '{"user_id": "12345"}'},
}
],
},
{
"role": "tool",
"tool_call_id": "call_123",
"content": '{"id": "12345", "name": "Alice", "email": "alice@example.com"}',
},
{"role": "assistant", "content": "I found user Alice with ID 12345."},
]
@pytest.fixture
def sample_tool_output_large():
"""Large tool output for compression testing (100 items)."""
return json.dumps(
[
{
"id": i,
"name": f"Item {i}",
"score": i * 0.1,
"status": "active" if i % 2 == 0 else "inactive",
}
for i in range(100)
]
)
@pytest.fixture
def sample_tool_output_with_errors():
"""Tool output containing error items."""
items = [{"id": i, "status": "success"} for i in range(20)]
items[5] = {"id": 5, "status": "error", "message": "Connection refused"}
items[15] = {"id": 15, "status": "failed", "exception": "TimeoutError"}
return json.dumps(items)
@pytest.fixture
def sample_system_prompt_with_date():
"""System prompt containing dynamic date."""
return "You are a helpful assistant. Current date: 2025-01-06. Help the user with their tasks."
@pytest.fixture
def sample_anthropic_messages():
"""Anthropic-style messages with content blocks."""
return [
{
"role": "user",
"content": [
{"type": "text", "text": "Analyze this image"},
{
"type": "image",
"source": {"type": "base64", "media_type": "image/png", "data": "..."},
},
],
}
]
# Mock client fixtures
@pytest.fixture
def mock_openai_response():
"""Mock OpenAI API response."""
mock = Mock()
mock.id = "chatcmpl-123"
mock.model = "gpt-4o"
mock.usage = Mock()
mock.usage.prompt_tokens = 100
mock.usage.completion_tokens = 50
mock.usage.total_tokens = 150
mock.choices = [Mock()]
mock.choices[0].message = Mock()
mock.choices[0].message.content = "This is a response."
mock.choices[0].message.role = "assistant"
mock.choices[0].finish_reason = "stop"
return mock
@pytest.fixture
def mock_openai_client(mock_openai_response):
"""Mock OpenAI client."""
client = Mock()
client.chat = Mock()
client.chat.completions = Mock()
client.chat.completions.create = Mock(return_value=mock_openai_response)
return client
# Storage fixtures
@pytest.fixture
def temp_sqlite_db():
"""Temporary SQLite database path."""
with tempfile.NamedTemporaryFile(suffix=".db", delete=False) as f:
yield f.name
Path(f.name).unlink(missing_ok=True)
@pytest.fixture
def temp_jsonl_file():
"""Temporary JSONL file path."""
with tempfile.NamedTemporaryFile(suffix=".jsonl", delete=False) as f:
yield f.name
Path(f.name).unlink(missing_ok=True)
# Provider fixtures
@pytest.fixture
def openai_provider():
"""OpenAI provider instance."""
from headroom.providers.openai import OpenAIProvider
return OpenAIProvider()
@pytest.fixture
def openai_tokenizer():
"""OpenAI token counter for gpt-4o."""
from headroom.providers.openai import OpenAITokenCounter
return OpenAITokenCounter("gpt-4o")
# Config fixtures
@pytest.fixture
def default_config():
"""Default HeadroomConfig."""
from headroom.config import HeadroomConfig
return HeadroomConfig()
@pytest.fixture
def smart_crusher_config():
"""SmartCrusher config for testing."""
from headroom.config import SmartCrusherConfig
return SmartCrusherConfig(
enabled=True,
min_items_to_analyze=3,
min_tokens_to_crush=0, # Always crush for tests
max_items_after_crush=10,
)
# Helper for creating RequestMetrics
@pytest.fixture
def sample_request_metrics():
"""Sample RequestMetrics for storage tests."""
from headroom.config import RequestMetrics
return RequestMetrics(
request_id="test-123",
timestamp=datetime(2025, 1, 6, 12, 0, 0),
model="gpt-4o",
stream=False,
mode="audit",
tokens_input_before=1000,
tokens_input_after=800,
tokens_output=200,
block_breakdown={"system": 100, "user": 200, "assistant": 500},
waste_signals={"json_bloat": 50},
stable_prefix_hash="abc123",
cache_alignment_score=85.0,
cached_tokens=100,
transforms_applied=["CacheAligner", "SmartCrusher"],
tool_units_dropped=1,
turns_dropped=0,
messages_hash="def456",
)