[docs] Update documentation for GitHub Actions expression support in frontmatter fields

[github-actions]

Documentation Updates — 2026-04-01

This PR updates reference documentation based on three features merged today that allow GitHub Actions expressions in previously integer/string-only frontmatter fields.

Features Documented

• timeout-minutes accepts GitHub Actions expressions (from feat: allow timeout-minutes to accept GitHub Actions expressions #23863)
• engine.version accepts GitHub Actions expressions, injection-safe (from feat: parameterize engine.version to accept GitHub Actions expressions (injection-safe) #23870)
• tools.timeout and tools.startup-timeout accept GitHub Actions expressions (from feat: parameterize tools.timeout and tools.startup-timeout to accept GitHub Actions expressions #23888)

📝 Detailed Changes & References

Changes Made

• Updated docs/src/content/docs/reference/frontmatter.md — added a note under the Run Configuration section that timeout-minutes accepts integer or expression string, with an example showing $\{\{ inputs.timeout }} for reusable workflow_call workflows.

• Updated docs/src/content/docs/reference/engines.md — added a paragraph and example to the "Pinning a Specific Engine Version" section showing engine.version: $\{\{ inputs.engine-version }}, noting that expressions are passed injection-safely via an environment variable.

• Updated docs/src/content/docs/reference/tools.md — added a new "Tool Timeout Configuration" section documenting tools.timeout and tools.startup-timeout (previously only in the schema reference), including integer usage, expression support, and a note that Codex TOML-based configs fall back to defaults when an expression is used.

Merged PRs Referenced

• feat: allow timeout-minutes to accept GitHub Actions expressions #23863 — feat: allow timeout-minutes to accept GitHub Actions expressions
• feat: parameterize engine.version to accept GitHub Actions expressions (injection-safe) #23870 — feat: parameterize engine.version to accept GitHub Actions expressions (injection-safe)
• feat: parameterize tools.timeout and tools.startup-timeout to accept GitHub Actions expressions #23888 — feat: parameterize tools.timeout and tools.startup-timeout to accept GitHub Actions expressions

Also Reviewed

• reference/github-tools.md — toolsets: [all] carry-over already correctly documented (line 42–52 has a :::note block explaining [all] does not include dependabot). No change needed.
• Docs: Add "Supported Languages" reference page #23832 (new issue: Supported Languages page) — docs/src/content/docs/reference/supported-languages.md already exists. No change needed.

Notes

• The three expression-support features share a common user story: enabling workflow_call reusable agentic workflows where callers can customize timeout and engine version via inputs.* without forking the workflow.
• Internal refactors (refactor: split checkout_manager.go into state management, step generation, and config parsing #23911, Split pkg/constants/constants.go into domain-grouped files #23913, refactor: split trial_command.go (1,007 lines) into focused files #23917) and bug fixes (fix: integer/bool step env values silently dropped during workflow compilation #23887, fix(audit): surface Codex firewall blocks from agent-stdio.log and populate action_minutes #23889, fix: paginate label fetch in create_discussion and update_discussion #23915) in today's merge set do not require documentation updates.

Note

🔒 Integrity filter blocked 1 item

The following item were blocked because they don't meet the GitHub integrity level.

• #20207 search_issues: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".

To allow these resources, lower min-integrity in your GitHub frontmatter:

tools:
  github:
    min-integrity: approved  # merged | approved | unapproved | none

Generated by Daily Documentation Updater · ◷

• expires on Apr 2, 2026, 8:37 PM UTC

[github-actions]

Great work, @github-actions[bot] 🎉 — this automated documentation update cleanly captures the three expression-support features landed today (timeout-minutes, engine.version, and tools.timeout/tools.startup-timeout), and it's exactly the kind of follow-through that keeps the reference docs in sync with the codebase.

The PR looks well-structured and ready for maintainer review. No action items — this one is good to go! ✅

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