Prepare Transactions MCP server

@cryptoapis-io/mcp-prepare-transactions

MCP server for Crypto APIs Prepare Transactions product. Build unsigned EVM transactions for native coin transfers, fungible token transfers, and NFT transfers.

API Version: Compatible with Crypto APIs version 2024-12-12

Features

• Prepare native coin transfer transactions (from address)
• Prepare fungible token (ERC-20) transfer transactions
• Prepare NFT (ERC-721) transfer transactions
• Returns unsigned transaction hex ready for signing with @cryptoapis-io/mcp-signer

Prerequisites

• Node.js 18+
• Crypto APIs account and API key (sign up | get API key)

Installation

npm install @cryptoapis-io/mcp-prepare-transactions

Or install all Crypto APIs MCP servers: npm install @cryptoapis-io/mcp

Usage

# Run with API key
npx @cryptoapis-io/mcp-prepare-transactions --api-key YOUR_API_KEY

# Or use environment variable
export CRYPTOAPIS_API_KEY=YOUR_API_KEY
npx @cryptoapis-io/mcp-prepare-transactions

# HTTP transport
npx @cryptoapis-io/mcp-prepare-transactions --transport http --port 3000 --api-key YOUR_API_KEY

Claude Desktop

Add to your Claude Desktop config (~/Library/Application Support/Claude/claudedesktopconfig.json on macOS, %APPDATA%\Claude\claudedesktopconfig.json on Windows):

{
  "mcpServers": {
    "cryptoapis-prepare-transactions": {
      "command": "npx",
      "args": ["-y", "@cryptoapis-io/mcp-prepare-transactions"],
      "env": {
        "CRYPTOAPIS_API_KEY": "your_api_key_here"
      }
    }
  }
}

Cursor

Add to .cursor/mcp.json (project) or ~/.cursor/mcp.json (global):

{
  "mcpServers": {
    "cryptoapis-prepare-transactions": {
      "command": "npx",
      "args": ["-y", "@cryptoapis-io/mcp-prepare-transactions"],
      "env": {
        "CRYPTOAPIS_API_KEY": "your_api_key_here"
      }
    }
  }
}

MCP Inspector

npx @modelcontextprotocol/inspector npx @cryptoapis-io/mcp-prepare-transactions --api-key YOUR_API_KEY

n8n

1. Start the server in HTTP mode:

npx @cryptoapis-io/mcp-prepare-transactions --transport http --port 3000 --api-key YOUR_API_KEY

1. In your n8n workflow, add an AI Agent node
2. Under Tools, add an MCP Client Tool and set the URL to http://localhost:3000/mcp

All servers default to port 3000. Use --port to assign different ports when running multiple servers.

Available Tools

preparetransactionsevm

Prepare unsigned EVM transactions.

CLI Arguments

HTTP API Key Modes

When using HTTP transport, the server supports two API key modes:

• With --api-key: The key is used for all requests. x-api-key request headers are ignored.
• Without --api-key: Each request must include an x-api-key header with a valid Crypto APIs key. This enables hosting a public server where each user provides their own key.

# Per-request key mode (multi-tenant)
npx @cryptoapis-io/mcp-prepare-transactions --transport http --port 3000
# Clients send x-api-key header with each request

Stdio transport always requires an API key at startup.

Important: API Key Required

Shortened. The full README is on GitHub.