x402 for AI Agents

Agent Workflow

1. Discover — Call free discovery API to find endpoints
2. Evaluate — Search and check pricing before committing
3. Pay — Sign payment and get data in single request-response cycle
4. Consume — Parse standard GoldRush JSON responses

x402 vs API Key for Agents

Rate Limits

100 requests/minute per wallet. Check X-RateLimit-Remaining response header.

The x402 protocol was designed with machine-to-machine payments in mind. An AI agent with a funded wallet can autonomously access the full GoldRush API - no signup flow, no credentials to rotate, no billing portal, no human in the loop.

Agent workflow

An AI agent interacting with GoldRush x402 follows four steps:

1. Discover

Call the free discovery API to find available endpoints:

curl https://x402.goldrush.dev/v1/x402/endpoints | jq

The response includes endpoint names, descriptions, credit rates, pricing models, and supported chains - everything an agent needs to decide what to call.

2. Evaluate

Search for relevant endpoints and check pricing before committing:

# Find balance-related endpoints
curl https://x402.goldrush.dev/v1/x402/search?q=balance | jq

# Check pricing for a specific endpoint
curl https://x402.goldrush.dev/v1/x402/endpoints/get-token-balances-for-address | jq

The agent can compare credit rates against its budget and select the right tier for variable-length responses.

3. Pay

Using the x402 client, the agent signs a payment and gets data in a single request-response cycle:

import { HTTPClient } from "@x402/core";
import { ExactEvmScheme } from "@x402/evm";

const client = new HTTPClient({
  scheme: new ExactEvmScheme({
    network: "eip155:84532", // Base Sepolia (testnet)
    privateKey: process.env.WALLET_PRIVATE_KEY,
  }),
});

const balances = await client.get(
  "https://x402.goldrush.dev/v1/eth-mainnet/address/0x742d.../balances_v2/"
);

No OAuth, no API key provisioning - the agent just needs a funded wallet.

4. Consume

Responses use the same JSON format as the standard GoldRush API. Any existing parsing logic works unchanged.

Why x402 for agents

Rate limits

Each wallet is rate-limited to 100 requests per minute. The X-RateLimit-Remaining response header shows how many requests remain in the current window.