mcp-pay Rust Payment awareness layer for MCP. A rail-agnostic manifest plus a reference HTTP 402 server.
mcp-pay extends the Model Context Protocol with a .well-known JSON manifest for declaring per-tool pricing and a Rust reference server that returns HTTP 402 on paid tools. Rail-agnostic across x402, MPP, Lightning and card.
Frequently asked questions
What is mcp-pay?
mcp-pay is Payment awareness layer for MCP. A rail-agnostic manifest plus a reference HTTP 402 server. It is part of the Neul Labs open-source portfolio (36 MIT-licensed projects for AI agent infrastructure). mcp-pay extends the Model Context Protocol with a .well-known JSON manifest for declaring per-tool pricing and a Rust reference server that returns HTTP 402 on paid tools. Rail-agnostic across x402, MPP, Lightning and card.
How do I install mcp-pay?
mcp-pay is available from its GitHub repository at https://github.com/neul-labs/mcp-pay. See the installation instructions in the README.
What language is mcp-pay written in?
mcp-pay is written in Rust.
Is mcp-pay open source?
Yes. mcp-pay is MIT licensed and publicly available at https://github.com/neul-labs/mcp-pay. All 36 Neul Labs projects are MIT licensed.
How does mcp-pay compare to alternatives?
See the detailed comparison at https://www.neullabs.com/compare/mcp-pay-vs-x402.