Cryptoapis MCP Signer MCP Server

MCP server for local transaction signing on EVM, UTXO, Tron, and XRP — no API calls needed

Local serverstdio

What is the Cryptoapis MCP Signer MCP server?

Most payments and commerce work still happens through a UI a human drives. Cryptoapis MCP Signer MCP server moves it into the conversation instead. MCP server for local transaction signing on EVM, UTXO, Tron, and XRP — no API calls needed.

The short version

MCP server for local transaction signing across EVM, UTXO, Tron, and XRP blockchains. No Crypto APIs HTTP calls — signing happens entirely on your machine. No API key required.

Getting it running

Installation goes through your MCP client rather than a global install: point it at @cryptoapis-io/mcp-signer on npm and it is fetched when the client starts. The copy-paste blocks for Claude Desktop, Claude Code and Cursor are further down this page.

The tools it exposes

The server publishes 7 tools. What each one is for:

  • Cursor — The Cursor tool exposed by this server
  • evm_sign — Sign an EVM transaction (Ethereum, Ethereum Classic, BSC, Polygon, Avalanche (C-Chain), Arbitrum, Base, Optimism, Tron)
  • utxo_sign — Sign a UTXO transaction (Bitcoin, Bitcoin Cash, Litecoin, Dogecoin, Dash, Zcash)
  • tron_sign — Sign a Tron transaction using secp256k1 (no TronWeb dependency)
  • xrp_sign — The xrp_sign tool exposed by this server
  • kaspa_sign — Sign a Kaspa transaction using schnorr (BIP340) via kaspa-wasm. Mainnet only
  • svm_sign — Partial-sign a Solana (SVM) x402 payment transaction — the buyer's source-authority signature only (the facilitator's feePayer slot stays unsigned

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.
  • Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

How it compares

Among the payments and commerce options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Cryptoapis MCP Signer's toolset — Cursor, evm_sign, utxo_sign and 4 more — is a fair guide to whether it matches your workflow. It is maintained by cryptoapis-io; worth a glance at recent repository activity before you build anything load-bearing on it.

This entry was verified against Cryptoapis MCP Signer's own documentation before publication; SyncDev keeps the directory reviewed rather than auto-generated.

Available tools

ToolWhat it does
CursorThe Cursor tool exposed by this server.
evm_signSign an EVM transaction (Ethereum, Ethereum Classic, BSC, Polygon, Avalanche (C-Chain), Arbitrum, Base, Optimism, Tron).
utxo_signSign a UTXO transaction (Bitcoin, Bitcoin Cash, Litecoin, Dogecoin, Dash, Zcash).
tron_signSign a Tron transaction using secp256k1 (no TronWeb dependency).
xrp_signThe xrp_sign tool exposed by this server.
kaspa_signSign a Kaspa transaction using schnorr (BIP340) via kaspa-wasm. Mainnet only.
svm_signPartial-sign a Solana (SVM) x402 payment transaction — the buyer's source-authority signature only (the facilitator's feePayer slot stays unsigned, signed at settle).

How to install the Cryptoapis MCP Signer MCP server

{
  "mcpServers": {
    "cryptoapis-mcp-signer": {
      "command": "npx",
      "args": ["-y", "@cryptoapis-io/mcp-signer"]
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Example prompts to try

  • Use Cryptoapis MCP Signer to Cursor.
  • Use Cryptoapis MCP Signer to evm sign.
  • Use Cryptoapis MCP Signer to utxo sign.

Frequently asked questions

It connects Cryptoapis MCP Signer to MCP-compatible AI assistants such as Claude and Cursor, exposing 7 tools (Cursor, evm_sign, utxo_sign, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Cryptoapis MCP Signer directly.