X402engine MCP Server

Most developer tooling work still happens through a UI a human drives. X402engine MCP MCP server moves it into the conversation instead. Agent-friendly MCP wrapper for x402engine with automatic capped USDC payments on Base and Solana.

The short version

Agent-friendly MCP server for x402engine. It lets agents discover and call pay-per-request APIs through HTTP 402, with automatic USDC payment on Base or Solana.

The tools it exposes

The server publishes 8 tools. What each one is for:

• Category — Tools
• Discovery — discover_services, service_health
• Audio — transcribe_audio
• Crypto — get_crypto_price, get_crypto_markets, get_crypto_history, get_trending_crypto, search_crypto, get_crypto_categories
• IPFS — pin_to_ipfs, get_from_ipfs
• Travel — search_flights, search_locations, search_hotels, search_cheapest_dates
• Base — Fund the wallet with USDC on Base. The x402 facilitator pays transaction gas; the wallet signs an EIP-3009 USDC authorization
• Solana — Fund the wallet with USDC on Solana and enough SOL for transaction fees

Getting it running

The server ships on npm as x402engine-mcp, so your MCP client can launch it on demand — there is no separate build step. Add the server block to your client's configuration, restart it, and the tools register themselves.

What it needs from you

Configuration is passed through the environment: X402_EVM_PRIVATE_KEY, X402_PAYMENT_NETWORK, X402_MAX_PAYMENT_USD, X402_SOLANA_PRIVATE_KEY, YOUR_BASE58_OR_JSON_PRIVATE_KEY, X402_BASE_URL. Treat anything key-shaped as a real credential — scope it to the minimum the server needs, and rotate it if it ever lands in a shared config.

How it compares

This sits in the developer tooling group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. X402engine MCP's toolset — Category, Discovery, Audio and 5 more — is a fair guide to whether it matches your workflow. It is maintained by agentc22; worth a glance at recent repository activity before you build anything load-bearing on it.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.

Things to watch

• It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
• Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
• Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.