Fuse402 — Fuse Network Business Payments & Loyalty API (x402)

Pay-per-request access to Fuse Network blockchain data and business payment infrastructure. Settles in USDC on Base via the x402 protocol — payable from any x402 client, including the Solid Agent Wallet and the Coinbase Agentic Wallet.

Live Deployment

• URL: https://ai.fuse.io
• Settlement network: Base mainnet (eip155:8453)
• Payment token: USDC
• Data network: Fuse mainnet (chain 122) via explorer.fuse.io Blockscout + viem

Endpoints

Method	Path	Price	Description
GET	/api/fuse/stats	$0.01	Real-time Fuse network statistics from Blockscout.
GET	/api/fuse/wallet/:address	$0.05	Balance, tx count, token-transfer count, last activity for any Fuse wallet.
GET	/api/fuse/defi/opportunities	$0.10	Live Fuse-chain DeFi products (DefiLlama TVL + Solid.xyz APY windows).
POST	/api/fuse/loyalty/create	$5.00	Deploys a real LoyaltyToken ERC-20 (mintable, burnable, owner + minter ACL) on Fuse via viem. Caller is the owner.
POST	/api/fuse/loyalty/mint	$0.50	Mints additional units of an existing LoyaltyToken (requires the deployer still holds the minter role).
GET	/api/fuse/loyalty/balance/:token/:address	$0.02	Reads any Fuse ERC-20 balance via viem.

Free routes:

• GET /health — health check
• GET /openapi.json — OpenAPI 3.1.0 spec (x402scan-compatible)
• GET /.well-known/x402 — well-known v1 discovery fallback

Loyalty token custody

/loyalty/create deploys a token on the caller's behalf:

• The caller's owner address (passed in the request body) becomes the on-chain owner and receives the initial supply.
• This service's deployer wallet is seeded as an initial minter so /loyalty/mint works out of the box.
• The owner can revoke the server's mint privilege at any time by calling setMinter(deployerAddress, false) on the token contract. After that, /loyalty/mint will revert for that token.

This service never holds the owner role and cannot transfer ownership, pause, or burn caller-owned tokens.

Tech stack

• TypeScript on Node 20+ (run with tsx)
• express 5.x
• @x402/express — x402 middleware
• @x402/core + @coinbase/x402 — CDP facilitator client
• viem — Fuse RPC + ERC-20 reads/writes + contract deployment
• zod — request validation
• Blockscout REST API at explorer.fuse.io, DefiLlama, Solid Analytics

Local development

1. Copy .env.example to .env and fill in:

   • PAY_TO_WALLET — wallet that receives x402 USDC payments on Base.
   • CDP_API_KEY_ID / CDP_API_KEY_SECRET — Coinbase CDP credentials (https://portal.cdp.coinbase.com).
   • DEPLOYER_PRIVATE_KEY — Fuse-mainnet EOA used to deploy loyalty tokens and mint on the caller's behalf. Needs a small FUSE balance for gas.

2. Install + run:

   pnpm install
   pnpm dev          # tsx watch
   pnpm test         # patches/extensions-forward smoke test
   pnpm build        # tsc --noEmit (typecheck only)

pnpm start runs the same TypeScript entry under tsx without a build step.

Deployment

Deployed on Vercel behind the ai.fuse.io custom domain. Configure all secrets as Vercel environment variables for the Production environment — nothing is hardcoded in vercel.json.

Entry point: src/index.ts (compiled by @vercel/node).

Usage

Use any x402-compatible client. Each protected route returns a 402 challenge until a valid X-PAYMENT header is presented. Example with curl (you'll see the 402 challenge body):

curl -i https://ai.fuse.io/api/fuse/stats

For real consumption use a wallet-aware client such as the Solid Agent Wallet or the Coinbase Agentic Wallet — both sign the 402 challenge and resend automatically, settling in USDC on Base. Any other agent framework with x402 support works too.