← AgentPay — 34 pay-per-call APIs

buy credits API

Prepaid credit pack - one $5 USDC x402 payment mints 600 call-credits (1 credit = $0.01, usable on every endpoint via X-AgentPay-Token; saves 20% vs pay-per-call).

$5 per request · USDC on Base (eip155:8453) · no signup, no API key

How it works

  1. Call it. POST your JSON body to /v1/buy-credits. An unpaid call answers 402 with signed payment terms — price, wallet, network.
  2. Pay. An x402 client (e.g. @x402/fetch) signs the terms and pays $5 in USDC on Base — no account, no API key.
  3. Retry. The same request is replayed with the payment proof and you get the JSON result.

Call it

# 1. POST JSON — an unpaid call answers 402 with signed payment terms
curl -i -X POST https://agentpay.help/v1/buy-credits \
  -H 'Content-Type: application/json' \
  -d '{}'

# 2. Pay & retry automatically with any x402 client, e.g. @x402/fetch
import { wrapFetchWithPayment } from "@x402/fetch";
const paidFetch = wrapFetchWithPayment(fetch, { x402Version: 2 });
const res = await paidFetch("https://agentpay.help/v1/buy-credits", { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({}) });
console.log(await res.json());

What you get back

{
  "token": "…",
  "credits": 0,
  "usage": "…"
}

Request body

{}

Buy credits API — FAQ

How much does the buy credits API cost?

$5 per call, settled in USDC on Base. No subscription — you pay per successful request, and prepaid credit packs save up to 30%.

Do I need an API key or account?

No. Your x402 client receives the 402 payment terms, pays USDC on Base, and retries automatically. No signup, no keys, no billing emails.

What does the response look like?

JSON. Shape: {"token":"string (ap_... bearer token)","credits":"number","usage":"string"}

How do agents integrate it?

Any HTTP client works: POST the JSON body, get a 402 with payment terms, sign with an x402 library (e.g. @x402/fetch), retry. The same tool is also available on our remote MCP server at https://agentpay.help/mcp.

Go deeper

Related: insurance-analysis ($0.10) · buy-credits-starter ($1) · buy-credits-pro ($20) Every endpoint is also an MCP tool on our remote MCP server. Prepaid credits: buy once, skip per-call payments.

Machine discovery: OpenAPI · x402 catalog · llms.txt