A search API built for AI agents

How an agent pays

The agent calls the endpoint. Without payment it gets HTTP 402 with the price and pay-to address. An x402 client signs a USDC payment and retries; the result comes back in the same request.

Connect it

Use the MCP endpoint https://x402serps.com/api/mcp in Claude Code, Cursor, OpenCode or n8n (guides below), or call the REST API directly.

How it works

Agents need search that they can call on their own: no signup flow, no OAuth, no monthly plan to choose. x402serps answers every unpaid request with an HTTP 402 that states the price. An x402 client signs a USDC payment on Base or Solana and repeats the request, and the agent gets its results.

The response format is small on purpose. Each result has a position, title, url and snippet, so ten results fit in a few hundred tokens. When the agent needs the page itself, /api/v1/extract returns clean markdown, and /api/v1/search-extract does both in one call.

The same tools are exposed over MCP at https://x402serps.com/api/mcp, so MCP clients see search, news, extract and the vertical endpoints as named tools with JSON schemas.

Request and response: /api/v1/search

POST /api/v1/search costs $0.004 per call. Send the parameters as a JSON body.

curl -X POST https://x402serps.com/api/v1/search \
  -H "content-type: application/json" \
  -H "X-Trial: 1" \
  -d '{"q":"x402 protocol","num":10,"gl":"us"}'

Example response (values shortened; field names are exactly what the API returns):

{
  "query": "x402 protocol",
  "provider": "primary",
  "results": [
    {
      "position": 1,
      "title": "x402",
      "url": "https://x402.org/",
      "snippet": "x402 is an open payment standard that lets clients pay for APIs and content over HTTP..."
    },
    {
      "position": 2,
      "title": "coinbase/x402: A payments protocol for the internet",
      "url": "https://github.com/coinbase/x402",
      "snippet": "x402 is a chain-agnostic protocol built around the HTTP 402 Payment Required status code..."
    }
  ]
}

Request and response: /api/v1/extract

POST /api/v1/extract costs $0.004 per call. Send the parameters as a JSON body.

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

Example response (values shortened; field names are exactly what the API returns):

{
  "url": "https://example.com",
  "finalUrl": "https://example.com",
  "title": "Example Domain",
  "contentType": "text/html",
  "markdown": "This domain is for use in documentation examples without needing permission...",
  "length": 156,
  "truncated": false
}

Use cases

• Research agents. Search, pick sources, extract and summarise.
• Coding agents. Look up current docs and error messages from inside Claude Code, Cursor or OpenCode.
• Workflow automation. Call the API from n8n or a cron job with a credit key.
• Local and shopping lookups. Use /api/v1/places and /api/v1/shopping for structured answers.

Paying for calls

Every call is priced on its own. With x402, an unpaid request returns HTTP 402 with the exact amount, asset and recipient for USDC on Base or Solana; your client signs a payment and repeats the same request, and results come back once the payment settles. No account or API key is involved. If you would rather pay by card, buy a credit pack on the pricing page and send Authorization: Bearer xs_.... Cached repeat queries cost half for credit keys, and failed calls are not charged. Paid calls have no per-minute rate limit.

FAQ