Show HN: File‑based sub‑agents for Codex CLI (tiny MCP server)

3 points

9 months ago

I built a tiny MCP server that adds task‑specific sub‑agents to Codex CLI via one tool: delegate. Agents are files (agents/.md|.json) with frontmatter you can review in PRs. DX: list_agents, validate_agents, copy/pasteable setup. Ops: stderr‑only debug and clear trust boundaries; guidance to isolate work with git worktree. Node ≥18; builds to dist/; the server itself makes no runtime network calls.

Under the hood: each call creates a temp workdir, writes AGENTS.md with the agent persona, and runs codex exec --profile <agent-profile> "<task>". For isolation, run in the temp dir (set mirror_repo=true) or point Codex at a worktree; profiles keep state separate.

Repo + docs: https://github.com/leonardsellem/codex-subagents-mcp?utm_sou...

I’d love feedback on safety/ops trade‑offs (e.g., sandbox modes, approvals) and which personas you’d add first (review, debugger, security, perf?).

Non‑goals: not a general‑purpose orchestrator—just a minimal, auditable bridge for Codex CLI.

If it’s useful, issues/PRs and agent recipe contributions are welcome.

4 comments