Pay for HTTP APIs on Gonka with GNK or USDC.
This is the public x402 facilitator for Gonka. An agent or app requests a paid URL, the server answers with HTTP 402, the client signs a Gonka transfer, and this service settles it on-chain. No accounts. No API keys.
Who this is for
Agents and buyers call paid APIs the same way they call any HTTP endpoint. When they see a 402, they pay and retry. See Agents & buyers.
Sellers put a price on an HTTP route, return 402 with payment details, then ask this facilitator to settle. See Sellers.
Registered paid URLs are on Resource listing. If you just want to see it work, start at Get started.
The payment flow
- The client sends a normal request to a paid URL.
- The server responds
402 Payment Requiredwith aPAYMENT-REQUIREDheader: network, asset, amount, andpayTo. - The client signs a Gonka transaction for that payment and retries with
PAYMENT-SIGNATURE. - The server calls
POST /settlehere. The signed tx is broadcast to Gonka. The server then returns the resource and aPAYMENT-RESPONSEwith the tx hash.
On Gonka, settlement is upfront: funds move before the resource is served. The client signs the full transaction. The facilitator only broadcasts it. It does not custody funds.
What you can pay with
| GNK | Native coin. Amounts are in ngonka (9 decimals). Transfer is MsgSend. |
|---|---|
| USDC | Bridged Circle USDC as a CW-20 token (6 decimals). Transfer is a contract transfer. |
| Network | cosmos:gonka-mainnet |
| Scheme | exact — pay at least the advertised atomic amount. |
Full constants live on Network & assets.
What each side does
| Client | Reads 402, signs a tx locally, retries with a header. Private keys never go to this server. Use the CLI or your own signer. |
|---|---|
| Resource server | Advertises price, checks the header, calls this facilitator, serves the work after a successful settle. |
| Facilitator | This site. /verify is read-only. /settle broadcasts and waits for inclusion. |
Protocol details, headers, and payload shapes are in Protocol. Endpoint contracts are in HTTP API.