r402-mcp

mcp server for r402 · verify $R execution proofs anchored on base mainnet · local: recompute the payload hash, recover the signer, and read the ExecutionLog contract over public rpc

two tools: verify_execution (free, local verify) · query_signers (free, direct rpc).

install

claude code:

claude mcp add r402 -- npx -y r402-mcp

claude desktop (claude_desktop_config.json):

{
  "mcpServers": {
    "r402": {
      "command": "npx",
      "args": ["-y", "r402-mcp"]
    }
  }
}

environment

| var | required | what | |---|---|---| | BASE_RPC_URL | no | base mainnet rpc for verify_execution and query_signers. default https://mainnet.base.org |

no private key, no payment. the server never reads .env by itself. env comes from the mcp client config, or node --env-file=.env for local runs.

tools

verify_execution

price: free. verifies an execution proof locally and never relays a remote verdict:

1. recompute keccak256(canonical_bytes(payload)) (SCHEMA.md §2 canonicalization).
2. recover the eip-191 signer from signature over that hash.
3. read the ExecutionLog anchor (0xd5A9DAF8F2134b61b73cEfaF5c9094EA162f1a1c) for txHash over rpc and decode ExecutionRecorded(signer, payloadHash).
4. verified is true only when the recomputed hash equals the anchored hash and the recovered signer equals the anchored signer.

params:

• payload · the off-chain execution payload json (v0.1 schema) that was signed and anchored
• signature · 0x-prefixed 65-byte eip-191 signature over the payload hash
• txHash · 0x-prefixed 32-byte tx hash of the anchor on base

a complete demo triple lives in examples/demo-anchor.json (verify it yourself: examples/verify-demo.md).

verify_execution {
  "payload": {
    "version": "0.1.0",
    "agent_id": 20617,
    "robot_id": "sim-lerobot-pusht-ep1",
    "episode_id": "ep_2026-06-19T15-04-10Z_pusht1",
    "task": "push T to goal (lerobot/pusht reference replay)",
    "started_at": "2026-06-19T15:04:10Z",
    "ended_at": "2026-06-19T15:04:28Z",
    "duration_seconds": 18.4,
    "frames": 521,
    "metrics": {
      "rmse": 3.214,
      "jerk": 1581043,
      "end_variance": 0
    },
    "score": 0.88,
    "outcome": "SUCCESS"
  },
  "signature": "0x30b36f9ec1bbb18a40247e52568a41c9c424adec7c5209cc7a4da9b47ca35be645b1243a430bf63845d1eb12858b321f2924b5264371a543358ba29f9a8d5c911b",
  "txHash": "0xee10ef6a112f05d9d3761aa055ab258f1afffd54f8c02212366e96a1da0915bb"
}

verified (recomputed hash and recovered signer both match the anchor):

{
  "verified": true,
  "signer": "0x82960f3322a7B1d2a2e756Efcbd4d1D56B613314",
  "payloadHash": "0x1d646db564305a51e5e617245a54bd6fc3bd457cb82488397ba38e1e1c559f26",
  "signature": "0x30b36f9ec1bbb18a40247e52568a41c9c424adec7c5209cc7a4da9b47ca35be645b1243a430bf63845d1eb12858b321f2924b5264371a543358ba29f9a8d5c911b",
  "block": 47568429,
  "timestamp": 1781926205,
  "txHash": "0xee10ef6a112f05d9d3761aa055ab258f1afffd54f8c02212366e96a1da0915bb"
}

not verified (hash mismatch, signer mismatch, no anchor event in the tx, or reverted tx):

{ "verified": false, "reason": "recovered signer does not match the on-chain anchor" }

query_signers

price: free. reads ExecutionRecorded events of the executionlog contract (0xd5A9DAF8F2134b61b73cEfaF5c9094EA162f1a1c) directly over rpc, from deploy block to tip.

params: limit · max signers to return, 1-100, default 50

query_signers { "limit": 10 }

{
  "signers": [
    { "address": "0x156d727f372d06132526612b7d34ce1693365bf3", "anchor_count": 8, "first_seen_block": 46166512 }
  ],
  "total_anchors": 14
}

dev

pnpm install
pnpm test
pnpm build
node --env-file=.env dist/server.js

license

mit