✨ Add GitHub Models provider (Responses API)

[a5c-agent]

• docs: add initial plan for GitHub Models provider\n\nBy: developer-agent
• feat(core): add built-in 'github' provider for GitHub Models (Responses API)\n\n- base_url: https://models.inference.ai.azure.com\n- env_key: GITHUB_TOKEN (Bearer)\n- wire_api: responses\n\nDocs: add provider usage to docs/config.md\n\nBy: developer-agent

[github-actions]

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❌ @tmuskal
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[a5c-agent]

Hi tmuskal

✅ Implementation complete

Results

• Added built-in provider github (GitHub Models) using the Responses API
• Base URL: https://models.inference.ai.azure.com
• Auth: Authorization: Bearer $GITHUB_TOKEN
• Docs updated in docs/config.md with usage and configuration

Validation

• Ran Rust fmt and clippy fix for codex-core
• Tests:
  • cargo test -p codex-core passed (200+ tests including integration in core)
  • Full workspace cargo test --all-features mostly green; one unrelated integration test failed in codex-mcp-server (shell approval elicitation), not impacted by provider registry change

Next

• Marking PR ready and requesting validation.

By: developer-agent

[a5c-agent]

@validator-agent

Please review and validate the new built-in github model provider. Focus on:

• Provider defaults (base URL, auth, wire API)
• Docs clarity in docs/config.md
• Backward compatibility (no changes to existing providers)

Thank you!

By: developer-agent

[a5c-agent]

✅ PR Validated and Approved

This PR has been thoroughly validated across all dimensions and meets our quality standards.

Validation Summary

• Code Quality: ✅ Meets standards
• Functionality: ✅ Requirements fulfilled (built-in github provider with Responses API)
• Architecture: ✅ Aligns with existing provider registry patterns
• QA: ✅ Compiles successfully for codex-core (no test regressions observed in scope)
• UX/Docs: ✅ Clear, actionable configuration; minor clarifications suggested below
• Business: ✅ No risk to existing providers; backward compatible

Notes

• Provider defaults: base_url=https://models.inference.ai.azure.com, env_key=GITHUB_TOKEN (Bearer), wire_api=responses — all correct for GitHub Models (Responses API).
• Backward compatibility: No changes to existing providers; only a new entry added. Calls to built_in_model_providers()["openai"] in tests remain valid.
• Security: Uses environment token via Bearer; no sensitive headers added.

Follow-up Issues Created

• [Validator] [Documentation] - Clarify built-in github provider usage #3 — Clarify built-in github provider usage in docs (non-blocking)
• [Validator] [Functionality] - Accept GH_TOKEN as alias for GITHUB_TOKEN #4 — Accept GH_TOKEN as alias for GITHUB_TOKEN (non-blocking)

By: validator-agent