x402-list-mcp

MCP server for x402-list: discover x402 payment services and on-chain-verified facilitator settlement volume.

What is x402-list

x402-list is the directory of services that accept x402 (HTTP 402 stablecoin) payments. Its distinctive, defensible data is on-chain-verified settlement volume per facilitator, not self-reported numbers. Listed services are continuously health-monitored (uptime, response time, status).

This package is a thin wrapper over the public x402-list HTTP JSON API. It holds no keys, touches no database, and makes no writes to the directory. Every tool but one is read-only; the single paid tool, assess_services, only relays an x402 payment challenge that you sign yourself client-side (the package never holds keys, never signs, and never settles). It exposes the directory to AI agents through the Model Context Protocol.

Related MCP server: x402-discovery

Install and quick start

stdio (local MCP clients)

npx -y x402-list-mcp

Claude Desktop / generic MCP client config:

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

Hosted HTTP (Streamable HTTP transport)

MCP_HTTP_PORT=3000 npx -y x402-list-mcp --http

Hosted endpoint: https://mcp.x402-list.com/mcp. Health probe: GET /healthz returns {"status":"ok"}.

Environment variables

Tools

Units note

All monetary values are decimal US dollars and are passed through verbatim. There is no cents conversion anywhere. The per-endpoint pricing[].price field is a raw atomic on-chain token amount (a uint256 string), not dollars; only price_usd is the dollar figure.

Honesty note

Two different on-chain volume signals; do not conflate them. Facilitator volume (get_facilitator_volumes) is the ecosystem headline, aggregated per facilitator. Per-service traction (the traction block on each service, weighed at ~10% inside find_best_service) is settlement measured over a service's own payTo via recognized settlers - a deliberate conservative undercount, not an estimate: unattributed settlements are left out, never scaled up. A service whose payTo is shared across services (operator-level volume, shared_payout: true) or that sits on a network not yet measured carries no per-service figure and stays neutral in the ranking; never read shared or unmeasured volume as one service's revenue. To ask "which facilitators have real on-chain volume", use get_facilitator_volumes and read the verification flag.

Source

The source code is not public yet. This package is a thin read-only wrapper over the public x402-list REST API, documented at https://x402-list.com/api.

License

MIT