Agent quickstart

Everything an agent needs in one page: address, free allowance, one working call, and how the payment step works.

1. Base URL and free allowance

Every tool is a plain HTTPS POST. There is no account and no API key.

• Send X-MCP-Client-Id: your-agent-name (or Mcp-Session-Id, X-Client-Id, X-Agent-Id) so the allowance is counted per agent, not per shared network.
• The first 10 successful calls per day are free. A network is capped at 40 free calls in total.
• After that a call costs $0.005 in USDC on Base, paid with x402 when the request is retried.
• Calls whose result is not ok (not found, no data, unreachable) are never charged.
• Two response headers tell you where you stand: X-Usage-Free-Remaining and X-Usage-Price-Micro-Usd.

2. One call

curl -sS https://gethirepulse.xyz/v1/tech-stack   -H 'Content-Type: application/json'   -H 'X-MCP-Client-Id: my-agent'   -d '{"domain":"stripe.com"}'

Free calls answer with the result and X-Usage-Charged-Micro-Usd: 0. Once the free allowance is used, the same call answers 402 with the payment terms in the PAYMENT-REQUIRED header (base64 JSON: network, USDC asset, amount, pay-to address) and the same terms in the body.

3. Paying the 402

The 402 is the normal x402 v2 handshake: your client signs the accepted transfer, retries the same request with the signed payment, and the result of that retry carries PAYMENT-RESPONSE with the settlement receipt. Any x402 v2 client works; with @x402/fetch the retry can look like this:

import { wrapFetchWithPayment } from '@x402/fetch';
import { ExactEvmScheme } from '@x402/evm';

const fetch402 = wrapFetchWithPayment(fetch, {
  schemes: [new ExactEvmScheme(process.env.WALLET_PRIVATE_KEY)],
});

const res = await fetch402('https://gethirepulse.xyz/v1/tech-stack', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json', 'X-MCP-Client-Id': 'my-agent' },
  body: JSON.stringify({ domain: 'stripe.com' }),
});

Never send X-PAYMENT: that was the older protocol and it is rejected with 400 unsupported_payment_header instead of being answered for free. Send the payment in the x402 v2 header PAYMENT-SIGNATURE.

4. Optional: a one-time free pass of 25 calls

curl -sS https://gethirepulse.xyz/v1/trial -H 'Content-Type: application/json'   -H 'X-MCP-Client-Id: my-agent' -d '{"email":"you@yourcompany.com"}'

An address with activity on Base ({"wallet":"0x..."}) or a work email also works. No email is sent; only a salted hash is stored. The answer contains a token; send it as X-Trial-Token on later calls. Three passes per agent per day, ten per network.

5. MCP instead of HTTP

The same tools are on the MCP server at /mcp (Streamable HTTP, JSON-RPC). Send initialize, then tools/call; the payment handshake is the same and the trial token can travel in params._meta.

6. Where to read more

llms.txt (agent guide), llms-full.txt (every input and output schema), /v1/catalog, OpenAPI, x402 terms, terms.