X402 Buyer

The universal buyer agent for the x402 economy.

An MCP server that lets Claude Desktop, Cursor, and Claude Code users discover, pay for, and call any x402 endpoint — automatically. Ask Claude a question, and it pays for the answer with USDC.

Discovery powered by Decixa (5,500+ verified x402 endpoints) with local registry fallback.

Install

Claude Desktop / Cursor

Add to your MCP config:

{
  "mcpServers": {
    "x402-buyer": {
      "command": "npx",
      "args": ["-y", "x402-buyer-mcp"]
    }
  }
}

Requirements

• Node.js 18+
• AgentCash wallet set up and funded with USDC on Base

Tools

How It Works

1. You ask Claude a question ("Is stripe.com secure?")
2. x402_discover searches Decixa + local registry for matching endpoints
3. x402_call pays the endpoint in USDC on Base via AgentCash
4. Data comes back, Claude synthesizes the answer

The local registry includes 8 Alderpost intelligence endpoints backed by premium sources (VirusTotal, People Data Labs, Hunter.io, AbuseIPDB, Qualys SSL Labs, NIH RxNorm, US Census, ESPN, The Odds API). Decixa extends discovery to the full x402 ecosystem.

Discovery Architecture

Primary: Decixa /api/agent/resolve — semantic search across 5,500+ verified x402 endpoints, ranked by latency, price, trust score, and capability match.

Fallback: Local registry of 8 curated Alderpost endpoints with full metadata. Used automatically if Decixa is unreachable.

This "soft swap" pattern means discovery always works, even if the network is down.

Local Registry Endpoints

Changelog

v2.0.0

• Decixa integration — discovery now queries Decixa's /api/agent/resolve API as primary source, with local registry as fallback (soft swap pattern).
• x402_discover returns results from the entire x402 ecosystem, not just Alderpost endpoints.
• Added capability mapping from natural language queries to Decixa's verb-based taxonomy.
• Updated tool descriptions to reflect ecosystem-wide discovery.
• First integration partner credit from Decixa.

v1.0.5

• Fixed npm bin entry and ESM module configuration.
• CLI moved to root cli.js.

v1.0.0

• Initial release with 4 tools and 8 Alderpost endpoints.

Credits

• Discovery: Decixa — the decision layer for AI agents
• Payment: AgentCash — USDC wallets for AI agents
• Intelligence: Alderpost — bundled intelligence APIs

Links

• Alderpost
• Decixa
• AgentCash
• GitHub

License

MIT — Alderpost LLC