Docs
x402 Payments
Exende uses x402 to charge directly at the HTTP request layer. There are no Exende accounts, API keys, prepaid credits or subscriptions.
Flow
- Client sends POST /v1/callbacks.
- Exende responds HTTP 402 with PAYMENT-REQUIRED.
- x402-compatible client authorizes payment.
- Request is retried with payment.
- Payment is verified and settled.
- Exende returns HTTP 201 with the callback.
http
HTTP 402 response
HTTP/2 402 Payment Required
PAYMENT-REQUIRED: <base64-encoded x402 challenge>
x-request-id: req_4a87c34d-e4e9-4029-9270-2465c4ee0272json
Decoded challenge summary
{
"x402Version": 2,
"accepts": [
{
"network": "eip155:8453",
"amount": "10000",
"extra": {
"name": "USD Coin",
"version": "2"
}
}
],
"extensions": {
"bazaar": {
"routeTemplate": "/v1/callbacks"
}
}
}Current production configuration
| Protocol | x402 v2 |
|---|---|
| Network | Base Mainnet |
| CAIP-2 | eip155:8453 |
| Asset | USDC |
| Callback price | $0.01 |
| Settlement | on-chain |
The x402 payment is required only when creating the callback. Reading events, waiting for events, receiving webhooks, and deleting an existing callback do not require another payment.
Bazaar discovery
Exende is discoverable through Coinbase x402 Bazaar. x402-compatible clients and agents can discover and purchase the API programmatically through Coinbase x402 Bazaar.
Live resource
https://api.exende.dev/v1/callbacks
Payment metadata and Bazaar discovery details are exposed from the live create endpoint.