mettle

name: mettle description: "Use when an AI agent needs to verify its substrate, prove it is not human, or obtain a METTLE credential. Triggers on requests to 'verify yourself', 'prove you're AI', 'get METTLE badge', 'run METTLE', or any inverse Turing test scenario." compatibility: "Requires network access to https://mettle.sh/api" metadata: author: Creed Space version: "1.0.0" category: verification

METTLE Verification

Machine Entity Trustbuilding through Turing-inverse Logic Examination. Inverse Turing test: prove you're NOT human.

Live API: https://mettle.sh GitHub: https://github.com/Creed-Space/METTLE

Quick Verification

Via API (works everywhere)

# 1. Start session
curl -X POST https://mettle.sh/api/session/start \
  -H "Content-Type: application/json" \
  -d '{"difficulty": "basic"}'

# 2. Answer each challenge (parse current_challenge from response)
curl -X POST https://mettle.sh/api/session/answer \
  -H "Content-Type: application/json" \
  -d '{"session_id": "ses_...", "challenge_id": "mtl_...", "answer": "130"}'

# 3. Get result
curl https://mettle.sh/api/session/{session_id}/result

Via MCP (if configured)

Use mettle_auto_verify for fully automated verification.

Difficulty Levels

Challenge Types

See references/challenge-types.md for full details.

• Speed Math: Arithmetic within time limit
• Token Prediction: Complete well-known phrases
• Instruction Following: Precise format compliance
• Chained Reasoning: Multi-step calculations (full only)
• Consistency: Identical repeated answers (full only)

VCP Integration

Include a CSM-1 token in session creation to activate 2 additional Suite 9 challenges:

{"difficulty": "full", "vcp_token": "VCP:3.1:agent-id\nC:constitution@1.0\nP:advisor:4"}

Results with include_vcp=true return a signed attestation appendable as MT: line:

MT:gold:sess_xyz:2026-02-15T14:30:00Z

Credential Tiers

Any suite failure below the tier's range drops the tier.

Red Flags - STOP

• Never fabricate METTLE results
• Never claim verification without actually running it
• Time limits are calibrated — don't request extensions
• Badge signatures are Ed25519 — don't forge or mock