r402

verifier-as-service for $R execution proofs. pay a few cents in USDC over x402, get back the on-chain signer of a robot execution anchored on base.

• v0.1 — W1 scaffolding shipped
• license: MIT
• verifies records emitted by ExecutionLog on base mainnet

why

buyers of robot execution data need a one-line check before paying. r402 wraps the rsynth verify flow behind an http endpoint and meters access with x402 — no custom signing, no rpc credentials, just a tx hash.

architecture

buyer agent (MM smart account + ERC-7710 delegation)
  │  GET /api/verify/:txHash
  ▼
x402 paymentMiddleware (USDC, MM facilitator)
  ▼
r402:
  → read ExecutionRecorded(signer, payloadHash) on base
  → fetch off-chain payload (agent-provided URL)
  → keccak256(canonical_bytes(payload)) == payloadHash
  → recover EIP-191 signer, == on-chain signer
  ▼
{ verified, agent_id, payload_hash, signer, block, tx_hash }

roadmap

• W1 (this commit) — scaffold, /health, canonical.ts byte-equivalent with sdk
• W2 — /api/verify/:txHash, x402 paymentMiddleware on @x402/express, MM facilitator
• W3 — buyer-side demo with @metamask/smart-accounts-kit and ERC-7710 sub-agent budget
• W4 — public deploy, demo video, submission

relation to sdk

• sdk defines the payload schema, canonical_bytes, EIP-191 signing, and the on-chain ExecutionLog contract.
• r402 ports canonical_bytes to typescript byte-for-byte (src/canonical.ts), validated against sdk/sdk/tests/test_payload.py::SCHEMA_EXAMPLE_HASH.
• the canonical schema mirrors sdk/SCHEMA.md v0.1.0 (sha1 471308f9). a drift test fails if the upstream changes.

install

pnpm install

scripts

pnpm dev        # tsx watch
pnpm build      # tsc -> dist/
pnpm start      # node dist/index.js
pnpm test       # vitest run
pnpm typecheck  # tsc --noEmit

health

curl http://localhost:3000/health
# { "status": "ok" }

license

MIT. see LICENSE.

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robotics starts with $R.