| name | taiko-x402 |
| description | Build and integrate x402 HTTP payment flows on Taiko using Taiko-operated facilitators. Use when adding per-request USDC payment gating to APIs deployed on Taiko (seller), building AI agents or clients that autonomously pay for x402 services (buyer), or configuring Taiko facilitators. Triggers: "x402", "HTTP payment", "pay per request", "monetize API", "USDC payment", "402 Payment Required", "facilitator.taiko.xyz", "paid API", "AI agent payments", "payment middleware".
|
x402 Payments on Taiko
Network Selection: If the user has not specified "hoodi" or "mainnet", always ask which network to use before proceeding.
x402 is an open HTTP payment protocol: a server responds 402 Payment Required with a price; a client signs an EIP-712 USDC authorization and retries. No accounts, sessions, or subscriptions needed — payment is the authentication.
Taiko runs two live facilitators that verify and settle payments on Taiko Mainnet and Hoodi testnet. These handle EIP-3009 signature verification and on-chain USDC transfer on behalf of the buyer.
Lifecycle
Buyer → GET /api → 402 (PAYMENT-REQUIRED header) → sign EIP-712 →
retry with PAYMENT-SIGNATURE → Facilitator verifies → 200 OK
Quick Decision
Networks
| Network | CAIP-2 | Facilitator |
|---|
| Taiko Mainnet | eip155:167000 | https://facilitator.taiko.xyz, https://x402.taiko.xyz |
| Taiko Hoodi | eip155:167013 | https://facilitator.taiko.xyz only |
No CDP API key required — Taiko facilitators are independent of Coinbase's CDP.
Common Errors
| Error | Fix |
|---|
No scheme registered for network | Register the EVM scheme for eip155:167000 or eip155:167013 |
Payment already attempted | Facilitator rejected payment — check USDC balance and allowance |
Invalid signature | Signer address doesn't match from in EIP-712 payload |
Token not supported | Use the USDC contract address listed in facilitators reference |
| 402 on every request | Middleware misconfigured — check route pattern and payTo address |
No default asset configured for network | Use price as { amount, asset } with the verified USDC token address for that Taiko network |
Network Contract Addresses
USDC addresses and chain IDs are maintained in the taiko skill:
Use taiko network info --json to retrieve current contract addresses programmatically:
taiko network info --json --network hoodi
taiko network info --json --network mainnet
MCP Tools for Verification
| Task | Tool |
|---|
| Verify USDC contract | get_contract_abi — confirm it's the USDC contract before integration |
| Check buyer USDC balance | read_contract — call balanceOf(address) on USDC |
| Debug payment failure | decode_calldata — decode payment tx input |
| Verify payment on-chain | get_transaction_info — confirm 402 payment tx hash |
| Look up facilitator address | search — find by name on the target network |
| Fee guidance | get_gas_price — help users estimate appropriate payment amounts |
Related Skills
References
- Server setup — Express/Next.js/Hono middleware, route config, Bazaar discovery
- Client setup — fetch/axios wrappers, wallet signer, USDC requirements
- Facilitators — Taiko facilitator URLs, USDC addresses, CAIP-2 identifiers
