SingIt MCP

Prices, models, web search and market data for your agent, over MCP. Paid calls are billed to your SingIt API key and stay inside that key's limits.

Docs · Developers · Main repository

SingIt runs a remote MCP server. There is nothing to install and no local process: your client connects to one URL.

https://app.singitai.app/mcp

Streamable HTTP, JSON responses only (no SSE, no sessions). MCP Registry name: app.singitai/singit. Server singit "SingIt x402", version 0.1.3, protocol 2025-06-18.

Quick start

The free tools and tools/list work without a key, so you can add the server and look around first.

Claude Code

claude mcp add --transport http singit https://app.singitai.app/mcp \
  --header "Authorization: Bearer $SINGIT_API_KEY"

Codex

codex mcp add singit --url https://app.singitai.app/mcp --bearer-token-env-var SINGIT_API_KEY

Cursor and other clients with a url and headers JSON config (see .mcp.json; Windsurf uses serverUrl, see docs/clients.md):

{
  "mcpServers": {
    "singit": {
      "url": "https://app.singitai.app/mcp",
      "headers": { "Authorization": "Bearer ${env:SINGIT_API_KEY}" }
    }
  }
}

More clients and per-client notes: docs/clients.md.

Related MCP server: Cralo

Get a key (only for paid tools)

Open the SingIt app, then Settings, API keys, and export the key as SINGIT_API_KEY in the environment that launches your client. Each key has its own daily and per-request caps and an expiry. A missing, empty or unexpanded key behaves like no key; a wrong or revoked key gets HTTP 401.

Tools

16 tools. The full table, with parameters, key scope and network, is in docs/tools.md.

Paid calls are charged to the key's own limits, in USDC. Web tools work on Base or Solana accounts; the market and data tools need a Base account for now. Read-only tools can still cost money, and repeating a paid call charges again. get_limits shows what the key has spent and what is left today.

Check that it works

Neither request needs a key and neither spends anything:

curl -sS https://app.singitai.app/mcp \
  -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"check","version":"1.0"}}}'

curl -sS https://app.singitai.app/mcp \
  -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/list"}'

Or run the bundled check, which compares the live server with tools.json (Node 20+, no dependencies):

npm run check:live

What is in this repository

The server itself runs inside the SingIt gateway and shares code with the rest of the payment stack, so its source lives in the main repository (sign402-gateway). This repository is where you find out how to connect and what the server offers.

Contributing and security

See CONTRIBUTING.md. Security problems: email contact@singitai.app, not a public issue (SECURITY.md). MIT licensed.