Get started

Three short paths: look at a 402, pay the demo as a buyer, or call the facilitator as a seller. Base URL for this deployment is .

1. See a 402

The demo resource is unpaid until you attach a signature. This request must return HTTP 402 and a PAYMENT-REQUIRED header.

curl -i {{BASE}}/demo

The JSON body is the same object as the header (decoded). accepts lists GNK and USDC. Pick one when you pay.

Request /demo now

The 402 body will appear here.

2. Pay the demo

You need Go and a Gonka private key whose address already holds GNK or bridged USDC. gonkalabs Git is temporarily unavailable — fetch the source from this website. The key stays on your machine.

curl -fsSL {{BASE}}/releases/x402-gonka-source.tar.gz | tar -xz
cd x402-gonka
go run ./cmd/x402-gonka pay --key "$GONKA_PRIVATE_KEY" --url {{BASE}}/demo
go run ./cmd/x402-gonka pay --key "$GONKA_PRIVATE_KEY" --url {{BASE}}/demo --asset usdc

The archive is on Source. Flags are on CLI. What the signer builds is on Agents & buyers.

Live settlement

These are the commands used to pay /demo with GNK. The hex key stayed in $GONKA_PRIVATE_KEY on the signer and was never sent to this host.

curl -i {{BASE}}/demo
curl -fsSL {{BASE}}/releases/x402-gonka-source.tar.gz | tar -xz
cd x402-gonka
go run ./cmd/x402-gonka pay --key "$GONKA_PRIVATE_KEY" --url {{BASE}}/demo

The unpaid curl returned HTTP 402. pay signed locally, retried with PAYMENT-SIGNATURE, and printed:

status=200
{
  "ok": true,
  "product": "x402-gonka",
  "message": "Payment settled on Gonka.",
  "payer": "gonka150c4lsmsdr23vly466lskajkfhqh7eghmyjern",
  "network": "cosmos:gonka-mainnet",
  "transaction": "23B76D1281F9EFCC7AFC90659480CF3219A7099959C0513720769F700E9B73B2",
  "explorer": "https://gonka.gg/tx/23B76D1281F9EFCC7AFC90659480CF3219A7099959C0513720769F700E9B73B2"
}

Then we checked the payer balance and the tx on rpc.gonka.gg:

curl -sS https://rpc.gonka.gg/chain-api/cosmos/bank/v1beta1/balances/gonka150c4lsmsdr23vly466lskajkfhqh7eghmyjern
curl -sS https://rpc.gonka.gg/chain-api/cosmos/tx/v1beta1/txs/23B76D1281F9EFCC7AFC90659480CF3219A7099959C0513720769F700E9B73B2

Open that hash on gonka.gg. USDC was not used in this run.

3. Call the facilitator

Sellers do not talk to the chain themselves. Discover kinds, then POST /settle after the client retries with PAYMENT-SIGNATURE.

curl -sS {{BASE}}/supported
curl -sS {{BASE}}/discovery/resources

How to emit 402 from your own API is in Sellers. Registered paid URLs are on Resource listing. Request and response bodies are in HTTP API.

Prerequisites