headroom/tests/parity
gglucass 0ce68dedd7
fix(proxy): restore Codex usage headers on WS and streaming SSE transports (#577) (#794)
## Description

Codex's subscription/rate-limit window (the `x-codex-*` headers) was
being
**stripped on every transport Codex actually uses**, so session/weekly
usage
never reached the Codex CLI's own `/status` display, Headroom
`/stats`/dashboard,
or any consumer that sniffs the client-facing handshake. This PR
restores it on
**both** the WebSocket and streaming-SSE paths — the two halves of #577
— in one
place.

Fixes #577

**Supersedes #582 and #590.** This PR incorporates #582's SSE fix
(carried verbatim
with a `Co-authored-by` trailer) and additionally forwards the window
onto the client
`101` on the WS path, which #582/#590's capture-only WS code cannot do.
Both can be
closed as superseded once this merges — GitHub closing keywords only
auto-close
issues (hence `Fixes #577` above), not PRs, so #582/#590 need a manual
close.

### WebSocket (`gpt-5.4+`)

OpenAI delivers `x-codex-*` **only** on the upstream WS handshake
response, never
in data frames. `handle_openai_responses_ws` accepted the client WS
*before* it
connected upstream and never read `upstream.response.headers`, so the
window was
dropped. This reorders the handler to **connect upstream first**,
extract the
`x-codex-*` subset, then **accept the client WS with those headers
attached** to
the `101`, and refresh the Python state for `/stats` parity.

### Streaming SSE (incorporated from #582, @m16khb)

Codex CLI almost always streams. `streaming.py` neither captured
`x-codex-*` into
`CodexRateLimitState` nor forwarded it — the forwarded-header filter
matched only
the substring `"ratelimit"`, which `x-codex-*` does not contain. This
calls
`update_from_headers()` **before** the `>=400` early-return (so a
streaming 429/5xx
still refreshes the window, matching the non-streaming handlers) and
widens the
forward filter to pass `x-codex-*`.

> Credit: the SSE fix is @m16khb's work from #582, carried here verbatim
with a
> `Co-authored-by` trailer so the maintainer gets a single PR covering
both
> transports. This supersedes #582/#590's **WS** capture (which only
writes
> `/stats`); the connect-before-accept reorder additionally forwards the
window to
> the client `101`, which capture-only cannot do. #590's optional
snapshot
> persistence is intentionally left out (separable; hot-path sync write;
doesn't
> help the `101`-sniff consumers).

## 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

- `openai.py`: add `_extract_codex_handshake_headers()` (strictly
`x-codex-*`, via
`raw_items()` to avoid `MultipleValuesError`; never
`set-cookie`/`authorization`).
- `openai.py`: reorder `handle_openai_responses_ws` — connect-only retry
loop runs
before `accept()`; `accept(headers=...)` carries the forwarded window;
first
client frame read afterward. HTTP fallback preserved; it now also
refreshes
  `/stats` from the HTTP response headers.
- `streaming.py`: capture `x-codex-*` on all statuses + widen the
forwarded-header
  filter (from #582).

### Diff-size note

The bulk of the `openai.py` line count is **whitespace-only
relocation**: the relay
block dedents one level out of the old per-attempt `async with`. Logical
change is
~290 lines. **Review with `?w=1`.** In API-key mode the handshake
carries no
`x-codex-*`, so the accept-header list is empty and the path behaves
exactly as
before — the fix only activates for ChatGPT-subscription auth.

## Testing

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

- WS: `test_ws_connect_happens_before_accept`,
`test_ws_forwards_codex_headers_to_client_accept`
(only `x-codex-*` forwarded; `set-cookie`/`authorization` excluded;
`/stats` refreshed),
`test_ws_connect_failure_falls_back_to_http`,
`test_ws_first_frame_timeout_after_connect_closes_upstream`.
- Fallback: `test_fallback_refreshes_codex_rate_limit_state`.
- SSE:
`test_codex_rate_limit_headers_captured_and_forwarded_in_streaming`,
  `test_codex_rate_limit_captured_on_streaming_429` (from #582).
- Wire-level e2e: `tests/e2e_ws_codex_usage_headers.py` boots the real
proxy + fake
upstream + real `websockets` client and reads the client `101` — closes
the gap
the unit tests stub (that uvicorn/starlette actually write
`accept(headers=...)`).

## Test Output

```
$ uv run pytest tests/test_proxy_streaming_ratelimit_headers.py \
                tests/test_ws_http_fallback.py \
                tests/test_openai_codex_ws_lifecycle.py \
                tests/test_openai_codex_ws_timings.py \
                tests/test_codex_rate_limits.py -q
63 passed in 0.83s

$ .venv/bin/python tests/e2e_ws_codex_usage_headers.py
[codex-hdr-e2e] client 101 headers:
    x-codex-primary-used-percent: 42
    x-codex-primary-window-minutes: 300
    x-codex-secondary-used-percent: 7
    x-codex-secondary-window-minutes: 10080
[codex-hdr-e2e] /stats reflects codex window (primary-used=42)
=== CODEX-HDR E2E ALL GREEN ===

$ uv run ruff check . && uv run ruff format --check <touched files>
All checks passed!
```

## 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

## Additional Notes

- **Why connect-before-accept (not capture-only).** Once `accept()`
sends the `101`,
headers can no longer be added; the `x-codex-*` window only exists after
we connect
upstream. Capturing into Python state (as #582/#590's WS code does)
fixes `/stats`
but not the Codex CLI's native display or any `101`-sniffing consumer —
those need
  the headers *on the client handshake*, which requires the reorder.
- **Security.** Forwarding is filtered strictly to `x-codex-*`;
`set-cookie`,
`authorization`, and all other upstream headers are never forwarded to
the client
  (asserted by both the unit test and the e2e).

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

## Contract Schemas

Per maintainer request: a JSON Schema (draft 2020-12) artifact
enshrining the OpenAI
interaction expectations this changeset relies on, so drift is
detectable later.

Committed following the repo's parity convention:
- schema:
`tests/parity/fixtures/codex_openai_contracts/codex-openai-interaction.schema.json`
- test: `tests/test_codex_openai_contract_parity.py` binds the schema to
the **live code**
in both directions, so drift fails CI rather than living only in this
description -
every declared `x-codex-*` header must be consumed by
`parse_codex_rate_limits`, and
`_extract_codex_handshake_headers` must forward exactly the declared
subset and never
`set-cookie`/`authorization`. No new dependency (does not pull in
`jsonschema`).

It covers, as `$defs`:

- `WSUpstreamHandshakeResponse` / `StreamingUpstreamResponseHeaders` -
the upstream
`x-codex-*` header family (full superset, with per-header wire pattern +
the parsed
semantic type) the WS and SSE captures read. Source of truth:
`parse_codex_rate_limits`.
- `ClientForwardedHandshakeHeaders` - the WS-101 **allow/deny**
contract: only
`x-codex-*` may be forwarded; `set-cookie`/`authorization` are
explicitly forbidden
  (`propertyNames` + `not`).
- `ClientForwardedStreamingHeaders` - the wider SSE forward set
(`*ratelimit*` OR `x-codex*`).
- `WSClientRequestFrame` / `WSRelayEvent` / `HTTPFallbackRequestBody` -
the WS frame
  envelopes and the unwrapped HTTP-fallback POST body.
- `CodexRateLimitStatsOutput` - the headroom `/stats` shape the parity
tests assert.

Validated with `jsonschema` (Draft202012 `check_schema` passes; positive
instances from
the e2e validate; negative instances - a leaked `set-cookie`, a fallback
body still
carrying a top-level `type` - are correctly rejected).

<details>
<summary><code>codex-openai-interaction.schema.json</code> (draft
2020-12)</summary>

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://github.com/chopratejas/headroom/contracts/codex-openai-interaction.schema.json",
  "title": "Codex <-> OpenAI interaction contracts (PR #794)",
  "description": "Enshrines the OpenAI interaction expectations this changeset depends on, so drift is detectable. Header values are transported as strings on the wire; the `x-headroom-parsed-type` annotation on each records the semantic type the parser (headroom/subscription/codex_rate_limits.py) coerces them to. Sources: codex_rate_limits.parse_codex_rate_limits (header family + gating), openai._extract_codex_handshake_headers (WS-101 forward filter), streaming.py (SSE forward filter).",
  "$defs": {
    "OpenAICodexWindowHeaders": {
      "title": "x-codex-*-{primary,secondary} window headers",
      "description": "A rolling rate-limit/subscription window. A window is materialized iff its `*-used-percent` header is present and numeric; `*-window-minutes` and `*-reset-at` are optional. `primary` and `secondary` are independent and either may be absent.",
      "type": "object",
      "properties": {
        "x-codex-primary-used-percent": {
          "type": "string",
          "pattern": "^\\d+(?:\\.\\d+)?$",
          "x-headroom-parsed-type": "float (0-100, NaN-guarded)",
          "description": "Percent of the primary window consumed. Gates creation of the primary window."
        },
        "x-codex-primary-window-minutes": {
          "type": "string",
          "pattern": "^\\d+$",
          "x-headroom-parsed-type": "int",
          "description": "Primary window size in minutes."
        },
        "x-codex-primary-reset-at": {
          "type": "string",
          "pattern": "^\\d+$",
          "x-headroom-parsed-type": "int (Unix epoch seconds)",
          "description": "Absolute reset time of the primary window."
        },
        "x-codex-secondary-used-percent": {
          "type": "string",
          "pattern": "^\\d+(?:\\.\\d+)?$",
          "x-headroom-parsed-type": "float (0-100, NaN-guarded)",
          "description": "Percent of the secondary window consumed. Gates creation of the secondary window."
        },
        "x-codex-secondary-window-minutes": {
          "type": "string",
          "pattern": "^\\d+$",
          "x-headroom-parsed-type": "int"
        },
        "x-codex-secondary-reset-at": {
          "type": "string",
          "pattern": "^\\d+$",
          "x-headroom-parsed-type": "int (Unix epoch seconds)"
        }
      },
      "additionalProperties": true
    },
    "OpenAICodexCreditsHeaders": {
      "title": "x-codex-credits-* headers",
      "description": "OpenAI credits balance. A credits snapshot is materialized iff `x-codex-credits-has-credits` is present; `unlimited` defaults to false; `balance` is optional.",
      "type": "object",
      "properties": {
        "x-codex-credits-has-credits": {
          "type": "string",
          "pattern": "^(?:[Tt][Rr][Uu][Ee]|[Ff][Aa][Ll][Ss][Ee]|[01])$",
          "x-headroom-parsed-type": "bool (true|false|1|0, case-insensitive)",
          "description": "Gates creation of the credits snapshot."
        },
        "x-codex-credits-unlimited": {
          "type": "string",
          "pattern": "^(?:[Tt][Rr][Uu][Ee]|[Ff][Aa][Ll][Ss][Ee]|[01])$",
          "x-headroom-parsed-type": "bool (defaults false when absent/unparseable)"
        },
        "x-codex-credits-balance": {
          "type": "string",
          "x-headroom-parsed-type": "str (empty -> null)",
          "description": "Free-form server string, e.g. \"$5.00\"."
        }
      },
      "additionalProperties": true
    },
    "OpenAICodexMetaHeaders": {
      "title": "x-codex meta headers",
      "type": "object",
      "properties": {
        "x-codex-limit-name": {
          "type": "string",
          "x-headroom-parsed-type": "str (empty -> null)",
          "description": "Active limit/model label, e.g. \"gpt-5.2-codex-sonic\"."
        },
        "x-codex-promo-message": {
          "type": "string",
          "x-headroom-parsed-type": "str (empty -> null)",
          "description": "Server announcement. Also gates snapshot creation when present."
        }
      },
      "additionalProperties": true
    },
    "OpenAICodexRateLimitHeaders": {
      "title": "Full x-codex-* header family OpenAI may emit",
      "description": "Superset of every x-codex-* header headroom reads. parse_codex_rate_limits returns a snapshot iff at least one of: a primary window, a secondary window, a credits snapshot, or a non-empty promo message is present; otherwise null (treated as a non-Codex response). All members are individually optional.",
      "type": "object",
      "allOf": [
        { "$ref": "#/$defs/OpenAICodexWindowHeaders" },
        { "$ref": "#/$defs/OpenAICodexCreditsHeaders" },
        { "$ref": "#/$defs/OpenAICodexMetaHeaders" }
      ],
      "additionalProperties": true
    },
    "WSUpstreamHandshakeResponse": {
      "title": "OpenAI WS handshake (101) response headers consumed by the WS fix",
      "description": "On the Codex WebSocket transport the x-codex-* window is delivered ONLY on the upstream handshake response (never in data frames). handle_openai_responses_ws reads upstream.response.headers here. This is the contract the connect-before-accept reorder depends on: if OpenAI ever moves these headers off the handshake (e.g. into a frame), the WS half of the fix goes stale.",
      "$ref": "#/$defs/OpenAICodexRateLimitHeaders"
    },
    "StreamingUpstreamResponseHeaders": {
      "title": "OpenAI streaming/HTTP response headers consumed by the SSE fix",
      "description": "On the streaming SSE/HTTP transport the same x-codex-* headers ride the HTTP response. streaming.py captures them on ALL statuses (including >=400) via update_from_headers, and forwards a wider set to the client (see ClientForwardedStreamingHeaders).",
      "$ref": "#/$defs/OpenAICodexRateLimitHeaders"
    },
    "ClientForwardedHandshakeHeaders": {
      "title": "Headers forwarded onto the CLIENT-facing WS 101 (allow/deny contract)",
      "description": "_extract_codex_handshake_headers forwards ONLY headers whose (lowercased) name starts with `x-codex-`. Every other upstream handshake header - notably set-cookie and authorization - MUST NOT appear on the client 101. Enforced by propertyNames below and asserted by the unit tests + tests/e2e_ws_codex_usage_headers.py.",
      "type": "object",
      "propertyNames": {
        "pattern": "^[Xx]-[Cc][Oo][Dd][Ee][Xx]-"
      },
      "not": {
        "anyOf": [
          { "required": ["set-cookie"] },
          { "required": ["Set-Cookie"] },
          { "required": ["authorization"] },
          { "required": ["Authorization"] }
        ]
      },
      "additionalProperties": { "type": "string" }
    },
    "ClientForwardedStreamingHeaders": {
      "title": "Headers forwarded to the client on the streaming SSE path",
      "description": "streaming.py forwards a header iff `\"ratelimit\" in name.lower()` OR `name.lower().startswith(\"x-codex\")`. This is a SUPERSET of the WS allow-list: it additionally passes generic *ratelimit* headers (e.g. the Anthropic streaming path) which do not contain the x-codex prefix.",
      "type": "object",
      "propertyNames": {
        "pattern": "(?:[Rr][Aa][Tt][Ee][Ll][Ii][Mm][Ii][Tt])|^[Xx]-[Cc][Oo][Dd][Ee][Xx]"
      },
      "additionalProperties": { "type": "string" }
    },
    "WSClientRequestFrame": {
      "title": "Client -> proxy WS data frame (Responses API over WS)",
      "description": "Codex sends the request as a response.create envelope. The HTTP fallback unwraps `.response` for the POST body, forces stream=true, and strips any top-level `type`. A flattened variant (no envelope, fields at top level) is also tolerated by the fallback.",
      "type": "object",
      "properties": {
        "type": { "const": "response.create" },
        "response": {
          "type": "object",
          "properties": {
            "model": { "type": "string", "description": "e.g. gpt-5.4" },
            "input": {
              "description": "String prompt or Responses-API structured input array.",
              "type": ["string", "array"]
            },
            "stream": { "type": "boolean" }
          },
          "required": ["model"],
          "additionalProperties": true
        }
      },
      "required": ["type", "response"],
      "additionalProperties": true
    },
    "WSRelayEvent": {
      "title": "proxy -> client WS data frame (relayed Responses API event)",
      "description": "SSE `data:` payloads relayed verbatim as WS text frames. `[DONE]` sentinels are dropped (not relayed). Every relayed event is a JSON object carrying a `type`. response.completed additionally carries usage under `response.usage`. anyOf (not oneOf): an error event also satisfies the looser lifecycle shape, which is fine.",
      "anyOf": [
        {
          "title": "lifecycle event",
          "type": "object",
          "properties": {
            "type": {
              "type": "string",
              "examples": [
                "response.created",
                "response.output_item.added",
                "response.completed"
              ]
            },
            "response": { "type": "object", "additionalProperties": true }
          },
          "required": ["type"],
          "additionalProperties": true
        },
        {
          "title": "error event",
          "type": "object",
          "properties": {
            "type": { "const": "error" },
            "error": {
              "type": "object",
              "properties": { "message": { "type": "string" } },
              "required": ["message"],
              "additionalProperties": true
            }
          },
          "required": ["type", "error"],
          "additionalProperties": true
        }
      ]
    },
    "HTTPFallbackRequestBody": {
      "title": "proxy -> OpenAI HTTP POST body on WS->HTTP fallback",
      "description": "Derived from WSClientRequestFrame: the inner `.response` object, with `stream` forced to true and any top-level `type` removed.",
      "type": "object",
      "properties": {
        "model": { "type": "string" },
        "stream": { "const": true },
        "input": { "type": ["string", "array"] }
      },
      "required": ["model", "stream"],
      "not": { "required": ["type"] },
      "additionalProperties": true
    },
    "CodexRateLimitStatsOutput": {
      "title": "headroom /stats output for the codex tracker (CodexRateLimitSnapshot.to_dict)",
      "description": "Internal (headroom-emitted) shape produced from the headers above; the WS and SSE update_from_headers parity tests assert this is refreshed. Included so drift in our own surface is also caught.",
      "type": "object",
      "properties": {
        "limit_id": { "const": "codex" },
        "limit_name": { "type": ["string", "null"] },
        "primary": { "$ref": "#/$defs/CodexWindowDict" },
        "secondary": { "$ref": "#/$defs/CodexWindowDict" },
        "credits": {
          "oneOf": [
            { "type": "null" },
            {
              "type": "object",
              "properties": {
                "has_credits": { "type": "boolean" },
                "unlimited": { "type": "boolean" },
                "balance": { "type": ["string", "null"] }
              },
              "required": ["has_credits", "unlimited", "balance"],
              "additionalProperties": false
            }
          ]
        },
        "promo_message": { "type": ["string", "null"] },
        "captured_at": { "type": "number", "description": "Unix epoch seconds (float)." }
      },
      "required": ["limit_id", "limit_name", "primary", "secondary", "credits", "promo_message", "captured_at"],
      "additionalProperties": false
    },
    "CodexWindowDict": {
      "oneOf": [
        { "type": "null" },
        {
          "type": "object",
          "properties": {
            "used_percent": { "type": "number" },
            "window_minutes": { "type": ["integer", "null"] },
            "window_label": { "type": "string", "description": "e.g. \"5h\", \"7d\"-style label; \"unknown\" when window_minutes is null." },
            "resets_at": { "type": ["integer", "null"], "description": "Unix epoch seconds." },
            "seconds_until_reset": { "type": ["integer", "null"] }
          },
          "required": ["used_percent", "window_minutes", "window_label", "resets_at", "seconds_until_reset"],
          "additionalProperties": false
        }
      ]
    }
  }
}
```

</details>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Co-authored-by: m16khb <m16khb@gmail.com>
2026-06-09 15:55:53 -05:00
..
fixtures fix(proxy): restore Codex usage headers on WS and streaming SSE transports (#577) (#794) 2026-06-09 15:55:53 -05:00
record_smart_crusher.py parity(smart_crusher): byte-equal harness — 17 fixtures green 2026-04-27 00:01:26 -07:00
recorder.py chore(rust): port ContentDetector to Rust + parity harness + PyO3 bridge 2026-04-27 23:57:39 -07:00