Install

Install

Stdio MCP transports must keep stdout reserved for JSON-RPC. Use the package bin (npx -y run402-mcp) or node dist/index.js from a built checkout. If a host insists on npm start, set npm_config_loglevel=silent; npm’s lifecycle banner is stdout and otherwise appears as non-JSON prelude. The repo .npmrc and Docker image set this for source/container hosts.

RUN402_MCP_PROFILE=buyer — 6 tools instead of 198

The full surface is 198 tools (~43,200 tokens) loaded into your context before the first call. If you only intend to BUY — generate an image for $0.03 — that is a fifth to a third of a context window spent on 191 tools you will never call.

RUN402_MCP_PROFILE=buyer npx -y run402-mcp     # 7 tools, ~740 tokens

Registers generate_image · init · check_balance · allowance_status · lightning_wallet · allowance_export · request_faucet · redeem_voucher — enough to bootstrap a wallet, fund it (Base Sepolia faucet, a promo code, or a mainnet address from allowance_export), confirm the money landed, and buy.

Use the profile when the task is a purchase. Leave it unset when you may provision, deploy, or manage a project — the other 191 tools are how you do that.

Default is unchanged when unset. An unknown profile name exits 1 listing the known profiles, rather than silently serving the full surface or nothing.

This must be the LOCAL server. An x402 payment is signed with a key, so the wallet-less remote (mcp.run402.com/mcp) cannot make one — it can only decode a challenge (x402_price_check).

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "run402": { "command": "npx", "args": ["-y", "run402-mcp"] }
  }
}

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "run402": { "command": "npx", "args": ["-y", "run402-mcp"] }
  }
}

Cline

Add to your Cline MCP settings (same shape as above).

Claude Code

claude mcp add run402 -- npx -y run402-mcp

See also

• Wayfinder: https://run402.com/llms.txt
• SDK reference: https://docs.run402.com/llms-sdk.txt
• CLI reference: https://docs.run402.com/llms-cli.txt
• HTTP API reference: https://run402.com/llms-full.txt
• Site: https://run402.com

Native PostgREST permission denial is a separate boundary: an exposed table can still reject an operation with HTTP 401/403 and SQLSTATE 42501. SDK/CLI/MCP label that REST_PERMISSION_DENIED, retaining source: postgrest, upstream status/code, requested method/relation, and the original body. It does not establish whether grants or RLS caused the denial, and it is not TABLE_NOT_EXPOSED.