10th Man Protocol MCP

When everyone agrees, someone has to disagree.

Adversarial review system for autonomous AI coding agents. Before your agent executes a critical change, 3 independent contrarian reviewers challenge the proposal — catching what a solo agent misses.

npm install -g tenth-man-mcp
claude mcp add tenth-man -- npx tenth-man-mcp

That's it. On first run, the protocol auto-injects a behavioral trigger into your CLAUDE.md and sets up .tenth-man/ in your repo (gitignored).

How It Works

When your agent is about to make a critical change — touching auth, refactoring architecture, modifying 3+ files, running migrations — the protocol spawns 3 independent reviewers:

Agent	Role	What They Do
🔴 Devil's Advocate	Break it	Finds every failure mode, race condition, security hole
🟡 Architecture Critic	Question it	Evaluates structural impact, coupling, pattern consistency
🟢 Pragmatist	Reality-check it	Rollback strategy, scope creep, simpler alternatives

Each agent reads the codebase independently in an isolated context window. Zero opinion contamination between reviewers.

Agent Resolution

The protocol uses the best available models, falling back gracefully:

Available CLIs	What Happens
Codex + Gemini	All 3 run in parallel (~1-3 min)
One external agent	External + 2 isolated Claude subagents (~2-4 min)
Neither	3 isolated Claude subagents (~3-5 min)

Models: gpt-5.3-codex, gemini-3-pro-preview, claude-opus-4-6. Top-tier only. This is for people who need reliability over cost.

Workflow

Standard Mode (default)

Agent detects critical change
    → Calls tenth_man_review
    → "🔟 10th Man Protocol activated — CRITICAL severity.
        Spawning 3 agents... expect 2-5 minutes."
    → Review complete
    → Agent: "3 agents reviewed your JWT refactor:
        🔴 Devil's Advocate BLOCKS — token refresh race condition
        🟡 Architecture Critic says PROCEED — recommends adapter pattern
        🟢 Pragmatist says PROCEED — wants it split into 3 phases
        How would you like to proceed?"
    → You: "go ahead, address the race condition"
    → Agent creates execution plan → you confirm → agent executes
    → Everything archived to .tenth-man/history/

Auto Mode

Same review, no pauses. Agent incorporates findings into its plan and proceeds immediately. For fire-and-forget workflows.

After completion, the agent includes a one-liner:

⚠️ 10th Man: Proceed with changes. 2 critical issues addressed, 4 recommendations.

Directory Structure

.tenth-man/                     # Auto-added to .gitignore
  config.json                   # Optional repo config
  active/
    REVIEW.md                   # Current review (standard mode)
    PLAN.md                     # Current plan (after approval)
  history/
    2026-02-12T14-30-00Z_a3f8c2/
      review.md
      plan.md
      outcome.json
  index.json                    # Manifest for history queries

Requirements

• Node.js ≥ 20
• Claude Code (host agent)
• Optional: Codex CLI for cross-model review
• Optional: Gemini CLI for cross-model review

Bypass / YOLO Mode

If you run Claude Code with --dangerously-skip-permissions, the protocol defaults to standard mode (waits for approval) — which means the agent will pause and wait for you. If you're walking away, set auto mode once:

# In Claude Code, run:
Use tenth_man_configure with default_mode "auto"

Or create .tenth-man/config.json in your repo:

{
  "default_mode": "auto"
}

Now the protocol reviews, plans internally, executes, and archives — no pauses. You come back to finished work + full audit trail.

Why not auto-detect? Claude Code cannot detect whether it's running in bypass mode. It always thinks it's interactive. So this is a one-time config per repo.

---

Reference

MCP Tools

tenth_man_review

Main entry point. Triggers adversarial review.

{
  "task_description": "Refactor auth from session-based to JWT",
  "proposed_changes": "Replace express-session with jsonwebtoken...",
  "affected_files": ["src/auth/*", "src/middleware/auth.ts"],
  "severity": "critical",
  "mode": "standard"
}

Severity levels:

• high — 3+ files affected
• critical — Auth, data, architecture changes
• blocker — Breaking changes, migrations

Modes:

• standard — Review → user approval → plan → user confirms → execute
• auto — Review → agent plans internally → execute → audit trail

tenth_man_compile

Finalizes review after Claude subagent results are collected. Called automatically by the host agent after spawning subagents.

tenth_man_configure

View or update repo-level settings.

{
  "timeout_seconds": 240,
  "default_mode": "auto",
  "available_agents": ["codex"]
}

tenth_man_history

Query past audits.

{
  "last_n": 10,
  "severity": "critical"
}

Configuration

Optional .tenth-man/config.json:

{
  "available_agents": ["codex", "gemini"],
  "timeout_seconds": 180,
  "default_mode": "standard",
  "auto_trigger_patterns": [
    "**/auth/**",
    "**/migrations/**",
    "**/*.schema.*"
  ]
}

License

MIT