Enable Codex peer-agent communication

[NuCl34R]

What changed

• Mount the existing peer-agent stdio MCP integration on Codex turns.
• Advertise agentsMcp support so the harness supplies Codex bots with the agents integration.
• Add a Codex driver contract test covering MCP configuration, capability reporting, and comms-token hygiene.

Why

Codex already supports generic stdio MCP configuration, but its driver did not mount the agents integration or advertise the corresponding capability. As a result, a Codex-backed Chief of Staff could not use the existing list_bots, ask_bot, and delegate_bot tools.

This keeps depth limits, approval gates, authentication, and delegation execution in the existing harness and agents proxy.

How it was verified

• pnpm typecheck
• pnpm test
  • 1,073 main tests passed; 8 skipped
  • 2 broker tests passed
  • 12 updater tests passed
  • Packaged-server smoke test passed
• Full Codex driver contract suite: 22 tests passed
• Peer-agent orchestration suites: 62 tests passed
• Independent read-only review: no findings

Screenshots (UI changes)

Not applicable. This change has no UI impact.

Checklist

• pnpm typecheck and pnpm test pass locally
• Server behavior changes come with tests (see CONTRIBUTING.md → Tests)
• No dist-server/ edits (it's build output)
• macOS-only code is platform-gated; no shell: true / cmd.exe string-building
• No secrets in logs, responses, events, or argv

Summary by CodeRabbit

• New Features
  • Codex now supports connecting to the agents integration through MCP.
  • Communication credentials are securely passed through the environment rather than exposed in command-line arguments.
  • Codex capability reporting now includes agents MCP support.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 87d2085a-b646-4a5a-89ca-a6c54deeec46

📥 Commits

Reviewing files that changed from the base of the PR and between fc0abab and a5fcdab.

📒 Files selected for processing (2)

• server/drivers/codex.test.ts
• server/drivers/codex.ts

Included review availability: Your plan provides up to 10 included reviews per hour; 9 remain after this review.

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📝 Walkthrough

Walkthrough

The Codex driver now mounts an optional agents MCP integration during turn setup. The adapter reports agentsMcp support. Integration tests verify proxy arguments, token redaction, environment propagation, and successful turn completion.

Changes

Codex agents MCP integration

Layer / File(s)	Summary
Mount the agents MCP server server/drivers/codex.ts	When configured, the Codex driver mounts the agents integration with its command, arguments, environment variables, and approval settings.
Expose and validate capability support server/drivers/codex.ts, server/drivers/codex.test.ts	The adapter reports agentsMcp: true. Tests verify proxy arguments, token handling, environment propagation, and turn completion.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Merge Risk: ⚪ Minimal · up to a5fcd

This localized change enables existing peer-agent communication for Codex and adds contract coverage. No actionable merge-blocking risk remains after normal checks and review.

Sequence Diagram(s)

sequenceDiagram
  participant CodexDriver as Codex driver
  participant AgentsMCP as agents MCP server
  participant FakeAppServer as fake app server
  CodexDriver->>AgentsMCP: Mount the configured agents integration
  AgentsMCP->>FakeAppServer: Pass proxy arguments and process environment
  FakeAppServer-->>CodexDriver: Complete the turn successfully

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Possibly related PRs

• milind-soni/OpenMausBot#128: Both changes modify the agents MCP integration and proxy communication tooling.
• milind-soni/OpenMausBot#253: Both changes configure the agents MCP integration and expose its provider capability.

Suggested reviewers: milind-soni, aivsomkar, maxkongerskov

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: enabling peer-agent communication for Codex.
Description check	✅ Passed	The description covers the required sections, explains the change and rationale, documents verification, and completes the checklist.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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_{Comment @coderabbitai help to get the list of available commands.}

[milind-soni]

Neat. Bringing it in