## Description
Codex's subscription usage window (primary/secondary rate-limit gauges)
stopped populating for ChatGPT-OAuth sessions. This PR restores it by
polling Codex's dedicated usage endpoint instead of relying on response
headers that are no longer sent.
### Why the previous approach no longer works
The existing code populates `CodexRateLimitState` from `x-codex-*`
rate-limit headers captured on the `/v1/responses` WebSocket handshake
(`update_from_headers` at WS accept). That worked when OpenAI returned
`x-codex-primary-used-percent`, `x-codex-primary-window-minutes`, etc.
on the handshake response.
OpenAI has since stopped sending those headers on the ChatGPT WebSocket
handshake. I confirmed this by faithfully replaying a real Plus-account
handshake (both `prewarm` and regular `request_kind`): no `x-codex-*`
headers come back on either. This matches OpenAI's own move to a
dedicated usage endpoint (`GET /backend-api/codex/usage` in CodexApi
mode) and reports such as openai/codex#14728. So `update_from_headers`
now runs on every accept but finds nothing to parse, and the window
silently stays empty.
The headers aren't coming back, so there is nothing to fix in the
parsing path. The data now lives behind a request we have to make
ourselves.
## Type of Change
- [x] Bug fix (non-breaking change that fixes an issue)
## Changes Made
- `subscription/codex_rate_limits.py`:
- `parse_codex_usage_payload()` / `update_from_usage_payload()` — map
the `GET /backend-api/wham/usage` JSON (`rate_limit.primary_window` /
`secondary_window` with `used_percent`, `limit_window_seconds`,
`reset_at`; `credits`; `rate_limit_reached_type`) into the existing
`CodexRateLimitState`. `limit_window_seconds` is converted to
window-minutes with the same round-up codex-rs uses (`(secs + 59) //
60`).
- `maybe_schedule_usage_poll()` — fire-and-forget, throttled to one
request per 60s, scoped to ChatGPT sessions (requires both a Bearer
token and `ChatGPT-Account-Id`; API-key traffic is skipped). Uses an
in-flight guard so concurrent accepts don't stack polls. Endpoint is
overridable via `HEADROOM_CODEX_USAGE_URL`.
- `proxy/handlers/openai.py`:
- At the Codex WS accept site, after the now-usually-empty
`update_from_headers` block, schedule the usage poll. Wrapped in
`contextlib.suppress` and fully non-blocking so it can never delay or
fail the WebSocket accept.
The old header-capture path is intentionally left in place as a no-cost
fallback in case OpenAI restores the headers.
## Testing
- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [x] Type checking passes (`mypy headroom`)
- [x] New tests added for new functionality
- [x] Manual testing performed (live `/wham/usage` replay against a Plus
account returned HTTP 200 with the expected schema; payload fixture in
tests mirrors that real shape)
## Test Output
```
$ uv run pytest tests/test_codex_rate_limits.py -q
........................................ [100%]
41 passed in 0.16s
$ uv run ruff check headroom/subscription/codex_rate_limits.py headroom/proxy/handlers/openai.py tests/test_codex_rate_limits.py
All checks passed!
$ uv run mypy headroom/subscription/codex_rate_limits.py
Success: no issues found in 1 source file
```
## Additional Notes
- New tests cover: full-payload mapping, window-minutes round-up,
credits balance kept only when `has_credits`, promo object vs string,
empty payload returns `None`, missing `used_percent` skipped,
header-gating (requires Bearer + account-id), poll throttling, and
no-event-loop safety.
- Scoping to `ChatGPT-Account-Id` keeps the poll off API-key traffic,
and the 60s throttle plus in-flight guard bound it to at most one
lightweight GET per minute per running proxy.
---------
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
`.gitattributes` declares `*.py text eol=lf` and `*.sh text eol=lf`, but
74 files (73 .py, 1 .sh) are stored in the index with CRLF line endings,
violating that contract. Every macOS/Linux clone reports these files as
"modified" on fresh checkout because git's diff engine sees the stored
bytes don't match the attribute contract, even though the working tree
and index match byte-for-byte.
Running `git add --renormalize .` rewrites each affected blob so the
stored form matches the attribute declaration. No semantic changes —
every affected file's diff is "N insertions, N deletions" with inserts
and deletes being the same lines modulo line endings.
Follow-up commit adds `.git-blame-ignore-revs` so `git blame` / GitHub
blame skip this mechanical commit.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Passively capture x-codex-* response headers from proxied Codex API
calls and surface them in /stats and the dashboard.
Unlike Anthropic subscription window tracking (which polls a dedicated
OAuth endpoint), Codex embeds rate-limit data directly in every API
response header — no polling, no new credentials needed.
Changes:
- headroom/subscription/codex_rate_limits.py: new module with
CodexRateLimitWindow, CodexCreditsSnapshot, CodexRateLimitSnapshot
data models and a thread-safe CodexRateLimitState singleton;
parse_codex_rate_limits() parses x-codex-primary/secondary-used-percent,
window-minutes, reset-at, credits, limit-name, and promo-message headers
- headroom/subscription/__init__.py: re-export new public symbols
- headroom/proxy/handlers/openai.py: call
get_codex_rate_limit_state().update_from_headers() after each
proxied /v1/chat/completions and /v1/responses response
- headroom/proxy/server.py: add codex_rate_limits key to /stats
via _get_codex_rate_limit_stats() helper
- headroom/dashboard/templates/dashboard.html: new OpenAI Codex
Rate-Limit Window panel (primary + secondary progress bars, credits
balance, limit name, reset countdown); hidden when no data
- tests/test_codex_rate_limits.py: 25 unit tests covering parsing,
window labels, reset time, credits, state updates
- docs/screenshots/subscription_window_active.png: updated screenshot
showing both Anthropic and Codex panels in the real dashboard
Header schema (from codex-rs/codex-api/src/rate_limits.rs):
x-codex-primary-used-percent / x-codex-primary-window-minutes /
x-codex-primary-reset-at (and secondary- variants)
x-codex-credits-has-credits / -unlimited / -balance
x-codex-limit-name / x-codex-promo-message
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
