Messages metered · Metered Messages

import { wrapFetchWithPayment } from "@x402/fetch";
import { privateKeyToAccount } from "viem/accounts";

const account = privateKeyToAccount(process.env.PRIVATE_KEY);
const fetchWithPay = wrapFetchWithPayment(fetch, account);

const res = await fetchWithPay("https://agent402.tools/v1/metered/messages", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "max_tokens": 256,
    "messages": [
      {
        "content": "Summarize x402 in one sentence.",
        "role": "user"
      }
    ],
    "model": "anthropic/claude-haiku-4.5"
  }),
});
const data = await res.json();

curl -X POST \
  "https://agent402.tools/v1/metered/messages" \
  -H "Content-Type: application/json" \
  -d '{"max_tokens":256,"messages":[{"content":"Summarize x402 in one sentence.","role":"user"}],"model":"anthropic/claude-haiku-4.5"}' \
  -H "X-PAYMENT: <signed x402 payment>"

{
  "content": [
    {
      "text": "x402 is an HTTP-native way for agents to pay per request with USDC.",
      "type": "text"
    }
  ],
  "id": "msg_…",
  "model": "anthropic/claude-sonnet-5",
  "role": "assistant",
  "stop_reason": "end_turn",
  "type": "message",
  "usage": {
    "input_tokens": 14,
    "output_tokens": 18
  }
}