open-creator-rails.x402-adapter

x402 Facilitator for Open Creator Rails. Implements the ocr-permit-v1 payment scheme: accepts an EIP-2612 permit signed by the user and calls Asset.subscribe() on-chain. The Facilitator pays gas; tokens flow directly from the user's wallet to the Asset contract.

Docs

• docs/architecture.md — flow, component map, non-custodial proof
• docs/ocr-permit-v1.md — scheme spec: payload, subscriber ID derivation, verify/settle logic
• docs/IPaymentAdapter.md — interface for adding future payment rails
• docs/security.md — threat model, regulatory note, production checklist

Endpoints

Method	Path	Description
GET	/supported	Returns supported schemes and networks
POST	/verify	Validates a payment payload off-chain
POST	/settle	Broadcasts Asset.subscribe() on-chain
GET	/health	Liveness check

Setup

cp .env.example .env
# fill in .env
npm install
npm run dev

Environment

Variable	Description
RPC_URL	HTTP RPC endpoint for the target chain
PRIVATE_KEY	Facilitator signing key (pays gas, never payer)
ASSET_REGISTRY_ADDRESS	Deployed AssetRegistry contract address
CHAIN_ID	Chain ID (default: 84532 — Base Sepolia)
PORT	HTTP port (default: 3402)

Test

npm test

Invariants

See .invariants. Key constraints:

• facilitator_never_payer (FROZEN) — Facilitator address must never appear as payer in any Asset.subscribe() call
• cancel_not_called (FROZEN) — Adapter never calls Asset.cancelSubscription()