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Author SHA1 Message Date
Abhay Singh
8cddf9b58e
fix(proxy/auth): match real Anthropic OAuth token prefix (sk-ant-oat) (#1672)
## Description

`classify_auth_mode` (in `headroom/proxy/auth_mode.py`) checks for
Anthropic
OAuth tokens with:

```python
if token.startswith("sk-ant-oat-"):
    return AuthMode.OAUTH
if token.startswith("sk-ant-api") or token.startswith("sk-"):
    return AuthMode.PAYG
```

But real Anthropic OAuth access tokens are **`sk-ant-oat01-...`** — a
version
number right after `oat`, **no dash**. So the `sk-ant-oat-` check never
matches a
real token; it falls through to the broad `sk-` rule and gets classified
**`PAYG`**.

That's exactly the misclassification the module is built to prevent: a
subscription/OAuth-bound request tagged `PAYG` gets the
aggressive-compression
policy — lossy compression, auto `cache_control`, `prompt_cache_key`
injection —
instead of the passthrough-prefer path OAuth is meant to get.

The existing tests didn't catch it because they use a synthetic
`sk-ant-oat-01-`
fixture (dashed) that happens to match the buggy prefix. Corroboration
that the
real shape is dash-less:
- `.gitguardian.yaml` fixture: `sk-ant-oat01-oauth-fixture`
- `tests/test_oauth_bearer_routing.py`: `sk-ant-oat01-xxx`
- the sibling helper `headroom/proxy/helpers.py` matches on `sk-ant-`
(no `oat-`)

## Fix

Match the dash-less `sk-ant-oat` prefix. It still matches the legacy
dashed
shape, and ordering relative to `sk-ant-api` / `sk-` is unchanged (OAuth
is
still checked first).

```python
if token.startswith("sk-ant-oat"):
    return AuthMode.OAUTH
```

## Type of Change

- [x] Bug fix (non-breaking change that fixes an issue)

## Changes Made

- `headroom/proxy/auth_mode.py`: match OAuth tokens on the dash-less
`sk-ant-oat` prefix.
- `tests/test_auth_mode.py`: add a regression test using the real
`sk-ant-oat01-...` format (the existing test keeps the legacy dashed
fixture, which still classifies correctly).
- `CHANGELOG.md`: Bug Fixes entry under Unreleased.

## Testing

- [x] New regression test added (`tests/test_auth_mode.py`)
- [x] Linting passes (`ruff check`) and formatting is clean (`ruff
format --check`)
- [ ] Full `pytest` deferred to CI (local-OOM reason below).

```text
$ uv run ruff check headroom/proxy/auth_mode.py tests/test_auth_mode.py
All checks passed!
```

## Real Behavior Proof

- Environment: Windows 11, Python 3.12.11, headroom from this branch.
Importing `headroom` loads the torch/transformers stack and a full
`pytest` gets OOM-killed on this box, so I verified the classification
logic with a dependency-free script and left the full pytest to CI.
- Exact command / steps: replicated the Bearer-token branch of
`classify_auth_mode` in a standalone script (only stdlib, no `headroom`
import) and ran the real and legacy token shapes plus PAYG keys through
it.
- Observed result: the real `sk-ant-oat01-...` now classifies OAUTH (was
PAYG before the change); the legacy dashed fixture still classifies
OAUTH; `sk-ant-api*` / `sk-*` keys still classify PAYG:

```text
OK: sk-ant-oat01-... -> OAUTH (was PAYG before fix)
OK: sk-ant-oat-01-... -> OAUTH (legacy fixture still matches)
OK: sk-ant-api* / sk-* -> PAYG (unchanged)
AUTH LOGIC VERIFIED
```

- Not tested: a live proxied Anthropic OAuth request end-to-end (needs a
real subscription token); the classification is pure and covered by the
regression test. Full local `pytest` deferred to CI (OOM, per above).

## 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
- [ ] New and existing unit tests pass locally with my changes — ran
lint + a standalone logic check; full pytest deferred to CI (local OOM,
disclosed above)
- [x] I have updated the CHANGELOG.md if applicable

## Additional Notes

- `crates/headroom-core/src/auth_mode.rs` carries the identical dashed
prefix (its Rust test matrix uses the same synthetic dashed fixture). I
scoped this PR to the Python runtime classifier since that's the
request-time path; happy to mirror the one-line fix in Rust in the same
PR or a follow-up — I just couldn't `cargo build` locally to verify, so
I left it out rather than push an unverified Rust edit.
- @JerrettDavis tagging you since you've been triaging these — small,
contained fix with a regression test if you have a moment.

Co-authored-by: JerrettDavis <mxjerrett@gmail.com>
2026-07-02 14:26:19 -07:00
Michael Sam
6d3f39f213
feat: add dashboard agent usage stats (#814)
## Description

Add a clear dashboard view for per-agent token usage so end users can
see Cursor, Claude, Codex, and other detected clients with before/after
token counts, tokens saved, and savings percentages. The stats API now
exposes a stable `agent_usage` object that the dashboard renders near
the top of the session view.

Fixes #

## Type of Change

- [ ] Bug fix (non-breaking change that fixes an issue)
- [x] 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

### New Files

**Tests:**
- `tests/test_dashboard_agent_usage.py` — Covers agent classification,
exact per-request aggregation, and aggregate fallback behavior.

### Modified Files

- `headroom/proxy/server.py` — Adds per-agent usage aggregation to
`/stats` with before tokens, after tokens, output tokens, saved tokens,
savings percentage, source, providers, and models.
- `headroom/dashboard/templates/dashboard.html` — Adds a prominent Agent
Usage panel with totals, coverage status, per-agent token-flow bars,
request counts, before/after tokens, saved tokens, and share of savings.

## Testing

- [x] Unit tests pass: `.venv312/bin/pytest
tests/test_dashboard_agent_usage.py`
- [x] Linting passes: `.venv312/bin/ruff check headroom/proxy/server.py
tests/test_dashboard_agent_usage.py`
- [x] Diff whitespace check passes: `git diff --check
origin/main...HEAD`
- [x] Dashboard smoke render: local proxy on `127.0.0.1:8790`, captured
Chrome headless screenshot of `/dashboard`
- [x] New tests added for new functionality

## 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
- [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 relevant unit tests pass locally with my changes
- [ ] I have made corresponding changes to the documentation
- [ ] I have updated the CHANGELOG.md if applicable

## Additional Notes

The agent usage panel uses exact request-log data when available. If
detailed request logs are empty, it falls back to aggregate
provider/model request counts and labels the coverage as aggregate
fallback so users are not misled.
2026-06-12 14:12:22 -05:00
chopratejas
ca9de93cfc fix: PR-F1 classify_auth_mode helper (Phase F kickoff)
Add the classify_auth_mode helper that maps inbound request headers to
one of three auth modes — Payg / OAuth / Subscription — at request
entry. The mode is the first-class policy axis Phase F's remaining PRs
(F2 cache+lossy gates, F3 TOIN per-tenant aggregation, F4
X-Forwarded-* skip) gate behavior on.

Detection rules (most-specific signal wins):
- Subscription UA prefix in user-agent → Subscription
- Bearer sk-ant-oat-* → OAuth (Claude Pro/Max)
- Bearer sk-ant-api* / Bearer sk-* → Payg
- Bearer <jwt> (3 dot-segments) → OAuth (Codex/Cursor/Copilot)
- Authorization present but not Bearer (AWS SigV4) → OAuth (Bedrock)
- x-api-key / x-goog-api-key → Payg
- Default → Payg

Hard constraints met: pure function, no regex, no silent fallback
(non-UTF-8 headers warn! and fall through), no hardcoded list (UA
prefixes in module-scope const ready to swap for config in a follow-up).

Files:
- crates/headroom-core/src/auth_mode.rs (new) — Rust impl
- crates/headroom-core/tests/auth_mode.rs (new) — 14 unit + 1 perf
- crates/headroom-core/benches/auth_mode.rs (new) — Criterion bench
- crates/headroom-core/Cargo.toml — add http dep + bench entry
- crates/headroom-core/src/lib.rs — pub mod auth_mode
- crates/headroom-proxy/src/proxy.rs — classify at request entry,
  store in extensions, log event=auth_mode_classified
- headroom/proxy/auth_mode.py (new) — Python port (parity)
- headroom/proxy/handlers/anthropic.py — wire into messages handler
- headroom/proxy/handlers/openai.py — wire into chat + responses
- tests/test_auth_mode.py (new) — 23 Python parity tests
- docs/auth-modes.md (new) — detection rules + how-to-extend

Tests: 15 Rust + 23 Python all green. cargo fmt + clippy + workspace
tests + ci-precheck all green.

Performance (criterion, M-series):
- auth_mode/classify/empty: 68 ns
- auth_mode/classify/payg_anthropic_api_key: 75 ns
- auth_mode/classify/oauth_jwt: 182 ns
- auth_mode/classify/subscription_claude_code: 81 ns

All paths well under the <10us budget (~50-150x headroom).

Refs: REALIGNMENT/08-phase-F-auth-mode.md PR-F1.
2026-05-03 17:20:14 -07:00