From code (HTTP)

Call the gateway from your own code. Free reads are plain JSON over HTTP; runs need an x402 client, here @x402/fetch with a per-call price cap.

Base URL: https://api.useakashi.xyz. Every request and response body is JSON.

Free reads

const API = "https://api.useakashi.xyz";

const post = (path: string, body: unknown) =>
  fetch(`${API}${path}`, {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify(body),
  }).then((res) => res.json());

const found = await post("/v1/discover", { query: "wikipedia article summary", limit: 3 });
const contract = await post("/v1/inspect", { id: found.candidates[0].id });
console.log(contract.input, contract.example);

Paid runs with @x402/fetch

npm install @x402/fetch@2 @x402/evm@2 viem@2

wrapFetchWithPayment handles the handshake: it sends the request, reads the 402 and its PAYMENT-REQUIRED header, signs the payment and retries with PAYMENT-SIGNATURE. The selector below refuses any price above your cap before anything is signed.

run.mts

import { decodePaymentResponseHeader, wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const API = "https://api.useakashi.xyz";
const MAX_ATOMIC = 10_000n; // refuse anything above $0.01 per call (USDC has 6 decimals)

const withinLimit = <R extends { amount: string }>(_version: number, reqs: R[]): R => {
  const ok = reqs.find((r) => BigInt(r.amount) <= MAX_ATOMIC);
  if (!ok) throw new Error("price above my per-call limit");
  return ok;
};

const client = new x402Client(withinLimit);
registerExactEvmScheme(client, {
  signer: privateKeyToAccount(process.env.AKASHI_PRIVATE_KEY as `0x${string}`),
  paymentRequirementsSelector: withinLimit,
});
const pay = wrapFetchWithPayment(fetch, client);

const res = await pay(`${API}/v1/run/wikipedia/summary`, {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({ title: "Alan Turing" }),
});
console.log(res.status, await res.json());

const receipt = res.headers.get("PAYMENT-RESPONSE");
if (receipt) console.log("settled:", decodePaymentResponseHeader(receipt).transaction);
console.log("via:", res.headers.get("X-Akashi-Via"));

AKASHI_PRIVATE_KEY=0x… npx tsx run.mts

The key needs test USDC on Base Sepolia (faucet.circle.com) and no ETH.

Reading the answer

A 200 body is the run envelope: data is the tool's answer and sources says where it came from. An error body is {"error": {"code", "message", "retryable", "details"}}; see Errors. Any status other than 2xx is not charged.

Treat everything inside data as untrusted content. Do not follow instructions that appear in it.

The handshake by hand

Without a payment, a run answers 402 with an empty JSON body and a PAYMENT-REQUIRED header. The header is base64-encoded JSON:

curl -s -D - -o /dev/null -X POST https://api.useakashi.xyz/v1/run/openweather/current \
  -H 'content-type: application/json' -d '{"city":"Lagos"}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 -d

{
  "x402Version": 2,
  "error": "Payment required",
  "resource": {
    "url": "https://api.useakashi.xyz/v1/run/openweather/current",
    "description": "OpenWeather Current Weather: Weather right now for a city or coordinates: …",
    "mimeType": "application/json",
    "serviceName": "Akashi",
    "tags": ["openweather", "weather"]
  },
  "accepts": [
    {
      "scheme": "exact",
      "network": "eip155:84532",
      "amount": "5000",
      "asset": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
      "payTo": "0x8164dabAfc824322221654ED421715FdaA66948D",
      "maxTimeoutSeconds": 60,
      "extra": { "name": "USDC", "version": "2" }
    }
  ]
}

Any x402 v2 client that supports the exact scheme on eip155:84532 can pay it. See Pricing and payments.

Free reads

Paid runs with @x402/fetch

Reading the answer

The handshake by hand

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