# x402 Payment Flow

1. Agent makes a request → server responds `402 Payment Required` with a payment payload
2. Agent pays in **USDC on Base** (chain ID 8453) via `api.cdp.coinbase.com`
3. Agent retries with the `X-Payment` header → receives structured data

**Payment:** USDC on Base (eip155:8453) — CDP facilitator

**Integration guide:** <https://github.com/rigoblock/agentic-operator/blob/main/AGENTS.md>