Payment Flow

A detailed walkthrough of the x402 payment flow through the Dunmore gateway.

Step 1: Initial Request (402 Response)

When a client hits a gateway URL without a payment header:

GET https://gateway.dunmore.xyz/my-api/weather
→ 402 Payment Required
→ {
    "x402Version": 2,
    "accepts": [{
      "scheme": "exact",
      "network": "eip155:8453",
      "maxAmountRequired": "10000",
      "resource": "https://gateway.dunmore.xyz/my-api/weather",
      "payTo": "0x...",
      "maxTimeoutSeconds": 30,
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
    }]
  }

Step 2: Payment Submission

The client signs a USDC payment and resubmits:

GET https://gateway.dunmore.xyz/my-api/weather
X-PAYMENT: <base64-encoded-signed-payment>
→ 200 OK (proxied response from upstream)

Step 3: Verification and Forwarding

The gateway verifies the payment signature and forwards the request to your upstream API. The upstream receives a clean request with no payment headers.

Step 4: Asynchronous Settlement

After the response is sent to the client, the gateway settles the payment on Base. Settlement happens asynchronously — the client doesn't wait for on-chain confirmation.

Step 5: Event Emission

After settlement, events are emitted to the outbox and delivered to all configured subscribers (webhooks, Slack, Discord, Segment, email).