MCP Web Search Server for AI Agents: $0.008 per Search, up to 10 Results

Give an MCP agent a web search tool. The search tool on https://api.switch402.com/mcp takes a query and returns up to 10 ranked results with title, URL and snippet for $0.008 USDC on Base per call, paid over x402. You are charged only when at least one result comes back.

Paid MCP tools answer an unpaid call with x402 payment terms (an isError result). A client that cannot pay x402 shows those terms instead of the result; use an x402-capable MCP client or wrapper that retries with params._meta["x402/payment"], or call the HTTP API from code. The quote tool is free.

• Tool arguments

  query (1 to 400 characters) and an optional limit from 1 to 10 (default 10). The price is $0.008 either way.

• Ranked results

  Each result has rank, title, url and snippet. Snippets, not full pages: pass a URL to scrape_lite ($0.003) to read it.

• Same tool over REST

  GET /v1/search?q=...&limit=10 or POST {"q": "...", "limit": 10} returns the same results for the same price.

• Not charged for nothing

  If no result comes back, or the call fails, the payment does not settle.

Cost: searches x $0.008. 5 searches per task for 100 tasks a month is $4.00; reading the top result with scrape_lite adds $0.003 per page.

Code examples

curl -s -X POST https://api.switch402.com/mcp -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' -H 'User-Agent: my-agent/1.0' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"search","arguments":{"query":"x402 payment protocol","limit":5}}}'
# Unpaid: an isError result with the x402 terms ($0.008). Retry with params._meta["x402/payment"].

curl -i -G https://api.switch402.com/v1/search \
  -H 'User-Agent: my-agent/1.0' \
  --data-urlencode 'q=x402 payment protocol' \
  --data-urlencode 'limit=5'
# 200 after payment: {"query": "...", "count": 5, "results": [{"rank": 1, "title": "...", "url": "...", "snippet": "..."}], ...}