MCP server

agent402-mcp · npm · MIT

An MCP server for any MCP client (Claude Desktop, Claude Code, Cursor and others). Flagship tools are listed as first-class MCP tools and the rest of the catalog is reachable through catalog.search, catalog.find and catalog.call, with skill packs surfaced as MCP prompts. The hosted connector at /mcp needs no install at all.

Install

npx -y agent402-mcp

Example

{
  "mcpServers": {
    "agent402": {
      "command": "npx",
      "args": ["-y", "agent402-mcp"],
      "env": { "AGENT402_CREDITS_KEY": "a402_YOUR_KEY" }
    }
  }
}

What it exposes

Flagship tools under dotted names: web.search, web.answer, web.news, browser.render, market.quote, audio.transcribe, memory.read, memory.write.
catalog.search / catalog.find + catalog.call for the rest of the catalog, keeping the context window small.
payment.info, server.describe and sellers.list for orientation, spend caps and the live seller leaderboards.
Skill packs as MCP prompts (prompts/list, prompts/get).

How payment works

AGENT_KEY (EVM) or SOLANA_AGENT_KEY: the server signs an x402 payment on a chain the tool accepts and retries.
AGENT402_CREDITS_KEY: sends Authorization: Bearer a402_...; the list price is debited only on a 200.
Neither: the pure-CPU tools pay with proof-of-work (about 0.2 s of CPU).
AGENT402_MAX_PER_CALL and AGENT402_BUDGET are enforced before a payment is signed. The hosted /mcp connector is also payable over MPP from an mppx-wrapped MCP client.

# Claude Code, hosted connector (no install)
claude mcp add --transport http agent402 https://agent402.tools/mcp

# Claude Code, local server paying from a wallet
claude mcp add agent402 -e AGENT_KEY=0x... -- npx -y agent402-mcp

A call that fails is not charged: settlement runs after the tool and only on a successful response. Background: Payments over MCP · MPP (Machine Payments Protocol).