Try without a wallet (25-call trial)

import { tool } from "ai"; import { z } from "zod";
export const webSearch = tool({
  description: "Search the web",
  parameters: z.object({ q: z.string() }),
  execute: async ({ q }) => (await fetch("https://x402serps.com/api/v1/search", {
    method: "POST", headers: { "content-type": "application/json", "X-Trial": "1" },
    body: JSON.stringify({ q }) })).json(),
});

Production: pay per call

Wrap fetch with an x402 client (e.g. @x402/fetch) and drop the trial header. The endpoint answers 402 with a price; the client signs $0.004 USDC and retries.

LangChain (Python) and AI SDK guides: https://x402serps.com/docs/langchain?utm_source=devto&utm_medium=article&utm_campaign=100sales and https://x402serps.com/docs/vercel-ai-sdk?utm_source=devto&utm_medium=article&utm_campaign=100sales

Try without a wallet (25-call trial)

import { tool } from "ai"; import { z } from "zod";
export const webSearch = tool({
  description: "Search the web",
  parameters: z.object({ q: z.string() }),
  execute: async ({ q }) => (await fetch("https://x402serps.com/api/v1/search", {
    method: "POST", headers: { "content-type": "application/json", "X-Trial": "1" },
    body: JSON.stringify({ q }) })).json(),
});

Production: pay per call

Wrap fetch with an x402 client (e.g. @x402/fetch) and drop the trial header. The endpoint answers 402 with a price; the client signs $0.004 USDC and retries.

LangChain (Python) and AI SDK guides: https://x402serps.com/docs/langchain?utm_source=devto&utm_medium=article&utm_campaign=100sales and https://x402serps.com/docs/vercel-ai-sdk?utm_source=devto&utm_medium=article&utm_campaign=100sales

Your coding agent can search the web with one URL and no API key. x402serps gives every MCP client 20 free searches or page extracts a day.

Claude Code

claude mcp add --transport http x402serps https://x402serps.com/api/mcp

Cursor (~/.cursor/mcp.json)

{"mcpServers":{"x402serps":{"url":"https://x402serps.com/api/mcp"}}}

Ask: "search the web for the latest MCP spec changes". The agent calls web_search; extract pulls clean page text.

After 20 calls

The agent gets a clear message on how to pay: $0.004 per search, $0.003 per extract, in USDC over x402 (Base or Solana), or card credits. Results come from a third-party search provider.

Guide: https://x402serps.com/free-search-mcp?utm_source=devto&utm_medium=article&utm_campaign=100sales

1. Look at the 402

curl -i -X POST https://x402serps.com/api/v1/search \
  -H "content-type: application/json" -d '{"q":"x402 protocol","num":5}'

The payment-required header lists both Base (eip155:8453) and Solana USDC options, each for 4000 units ($0.004).

2. Try it free

curl -X POST https://x402serps.com/api/v1/search -H "content-type: application/json" \
  -H "X-Trial: 1" -d '{"q":"x402"}'

Send X-Trial: 1 for 25 free calls, with no wallet or key.

3. Pay with x402 from Node

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

const account = privateKeyToAccount(process.env.AGENT_KEY); // a low-balance agent wallet
const pay = wrapFetchWithPayment(fetch, account);

const r = await pay("https://x402serps.com/api/v1/search", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({ q: "best MCP servers 2026", num: 10, freshness: "week" }),
});
const { results } = await r.json();
console.log(results.map(x => `${x.position}. ${x.title} ${x.url}`).join("\n"));

Use a dedicated wallet with a small balance and a spending cap.

4. Or use it over MCP

Add the remote server https://x402serps.com/api/mcp (streamable HTTP; MCP Registry name com.x402serps/search). Tools include web_search, news_search, extract, places_search and deep_research.

5. No wallet? Use an optional card key

Buy a prepaid credit pack by card at https://x402serps.com/pricing?utm_campaign=100sales#credits. You get an xs_... key; send it as Authorization: Bearer xs_.... 1 credit = $0.001, so a search is 4 credits and an extract is 3. x402 payments still work without any key.

Pricing (as of 3 Nov 2026)

Search is $0.004 per 10 results and extract is $0.003 per URL. Results come from a third-party search provider. Failed calls are not charged.

Docs: https://x402serps.com/docs?utm_source=hashnode&utm_campaign=100sales