A0nexus Bitcoin MCP Server

a0nexus-bitcoin-mcp

Live Bitcoin data + AI forecasts, right inside Claude (and any MCP-capable AI app).

This is a Model Context Protocol server that gives your AI assistant real-time Bitcoin network intelligence — chain height, hashrate, mempool congestion, fee estimates — plus AI price and fee forecasts, all as tools it can call mid-conversation. Data comes from the a0nexus.com Bitcoin Intelligence API.

Live Bitcoin fees and network status are free and need no wallet — install it and ask your assistant "what's the current Bitcoin fee?" right away. The differentiated tools (forecasts, fee forecast, confirmation ETA, mempool depth, intelligence brief) are pay-per-call: each request is settled with a few cents of USDC on Base via x402 (HTTP 402) — no account, no signup, no subscription. You only enable paid tools if you want them.

Install it with a single npx line (below). Node 18+ required.

Tools

Free (no wallet needed)

Paid (require a funded Base wallet — see Paid tools)

Install

Add the server to your AI app's MCP config. All three use the same one-line npx command — no clone, no build, no global install.

Claude Desktop

Edit claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/claude_desktop_config.json, Windows: %APPDATA%\Claude\claude_desktop_config.json):

{
  "mcpServers": {
    "a0nexus-bitcoin": {
      "command": "npx",
      "args": ["-y", "a0nexus-bitcoin-mcp"],
      "env": {
        "BTCI_API_URL": "https://a0nexus.com"
      }
    }
  }
}

Claude Code

Add an .mcp.json at your project root:

{
  "mcpServers": {
    "a0nexus-bitcoin": {
      "command": "npx",
      "args": ["-y", "a0nexus-bitcoin-mcp"],
      "env": {
        "BTCI_API_URL": "https://a0nexus.com"
      }
    }
  }
}

Cursor

Edit ~/.cursor/mcp.json (global) or .cursor/mcp.json (per-project):

{
  "mcpServers": {
    "a0nexus-bitcoin": {
      "command": "npx",
      "args": ["-y", "a0nexus-bitcoin-mcp"],
      "env": {
        "BTCI_API_URL": "https://a0nexus.com"
      }
    }
  }
}

Restart the app. Your assistant can now fetch live Bitcoin fees and network status for free immediately — try asking "what's the current Bitcoin fee?"

Paid tools

The free tools work with no wallet at all. To unlock the paid tools, add two environment variables to the env block above:

"env": {
  "BTCI_API_URL": "https://a0nexus.com",
  "BTCI_MCP_PAYMENT": "real",
  "BTCI_MCP_PRIVATE_KEY": "0x……"
}

• BTCI_MCP_PAYMENT: set to real to pay actual USDC. (Leave it unset, or none, for free-only operation.)
• BTCI_MCP_PRIVATE_KEY: the private key of a Base wallet holding a little USDC. Each paid call spends that endpoint's price (a few cents). Fund it with only what you're comfortable spending — call get_pricing to see exact per-endpoint costs.
• BTCI_MCP_NETWORK (optional): base (default) or base-sepolia for testnet.

Treat the private key like any secret: use a dedicated low-balance wallet, and never commit it to source control.

How it works

Paid endpoints use the x402 standard: the server requests a resource, the API replies HTTP 402 Payment Required with a price, the client signs a USDC transfer on Base and retries, and the API returns live data. It's true pay-per-call metering — no account, no signup, no monthly bill. You pay only for the calls your assistant actually makes.

Learn more and see live pricing at a0nexus.com.

License

MIT