[aw-failures] [fix][P0] Pin Codex CLI back from 0.133.0 — `stream_options.include_usage` rejected by `gpt-5.5`

[github-actions]

Problem statement

After PR #34390 (merged 2026-05-24T12:59:44 UTC) bumped DefaultCodexVersion from 0.130.0 to 0.133.0, every Codex-engine workflow run fails deterministically with HTTP 400 Unknown parameter: 'stream_options.include_usage' from the OpenAI chat completions API. The Codex CLI retry budget (3 retries on top of the initial attempt = 4 attempts) exhausts on identical errors and the run exits with code 1.

This breaks all Codex-engine workflows on main. See the parent report #34521 for the full 6h failure analysis.

Affected workflows and run IDs

Last 6h (2026-05-24 17:56 → 19:10 UTC):

Workflow	Run	Event
Daily Cache Strategy Analyzer	§26369636900	schedule
Changeset Generator	§26369303262	pull_request
Smoke Codex	§26369303293	pull_request
Changeset Generator	§26368932369	pull_request
Smoke Codex	§26368932442	pull_request
Changeset Generator	§26368599354	pull_request
Smoke Codex	§26368599382	pull_request

All 7 runs use engine_id: codex, model: gpt-5.5, codex_app_server.client_version: 0.133.0.

Probable root cause

Codex CLI 0.133.0 sends stream_options.include_usage: true in the chat completions request body. The gpt-5.5 model endpoint rejects this parameter:

{
  "error": {
    "message": "Unknown parameter: 'stream_options.include_usage'.",
    "type": "invalid_request_error",
    "param": "stream_options.include_usage",
    "code": "unknown_parameter"
  }
}

This is an upstream Codex regression — the CLI emits an OpenAI SDK parameter that the configured GitHub-models-routed gpt-5.5 endpoint does not accept. The previous pin (0.130.0) does not emit this field and has been observed working in baseline runs (e.g. §26184060675, Daily Cache Strategy Analyzer, 33 OpenAI requests, conclusion success).

Specific proposed remediation

Pick one (recommended first):

1. Partial revert of Bump pinned Copilot/Codex/GitHub MCP versions and regenerate workflow artifacts #34390: open a follow-up PR that pins DefaultCodexVersion back to 0.130.0 while keeping DefaultCopilotVersion: 1.0.52 and DefaultGitHubMCPVersion: v1.0.5. Regenerate lockfiles. Constants live in:
   • pkg/workflow/codex_engine.go (search for DefaultCodexVersion)
   • update pkg/workflow/js/version.js and any per-workflow lockfiles regenerated by make regen.
2. Wait for Codex 0.134+: if upstream ships a fix that omits stream_options.include_usage when the target endpoint doesn't accept it, bump to the patched version instead of reverting.
3. Upstream report: file a bug at openai/codex (or the appropriate GitHub-hosted equivalent) attaching the request trace and the gpt-5.5 400 response. Note that codex_app_server.client_version: 0.133.0 is the breaking version.

Success criteria / verification

• DefaultCodexVersion no longer 0.133.0 on main.
• Smoke Codex run on a fresh PR succeeds (conclusion: success, error_count: 0).
• Daily Cache Strategy Analyzer next scheduled run completes with at least 1 successful agent turn (compare against baseline of 33 OpenAI requests in audit-diff).
• No new occurrences of stream_options.include_usage in agent-stdio logs across the 6h window after the fix lands.

Parent report

#34521
Related to #34521

Generated by 🔍 [aw] Failure Investigator (6h) · opus47 15.3M · ◷

• expires on May 31, 2026, 7:22 PM UTC