io.github.CryptoAPIs-io/mcp

Crypto APIs MCP Servers

MCP (Model Context Protocol) servers for Crypto APIs — blockchain data, transactions, fees, signing, HD wallets, market data, and more. Works with Claude Desktop, Cursor, Windsurf, n8n, and any MCP-compatible AI client.

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

API docs: developers.cryptoapis.io

Quick Start

Prerequisites

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

Install a single server

npx @cryptoapis-io/mcp-address-latest --api-key YOUR_API_KEY

Install the combined server (14 products in one process)

npx @cryptoapis-io/mcp --api-key YOUR_API_KEY

Every tool is named <product>__<tool> (e.g. block_data__evm_block_data). This does not include mcp-signer, mcp-x402-pay, or mcp-x402-accept — install those separately if you need local signing or x402 payments.

Remote MCP Server

Crypto APIs provides an official remote MCP server with HTTP Streamable transport at https://ai.cryptoapis.io/mcp.

This is a multi-tenant server — pass your API key via the x-api-key header with each request. No installation or self-hosting required.

Use this when you need HTTP transport without running your own server (e.g. with n8n, custom AI agents, or any HTTP-based MCP client).

Packages

Package	npm	GitHub	Description
@cryptoapis-io/mcp	npm	GitHub	Combined server — bundles the 14 non-signing products below into one process
@cryptoapis-io/mcp-address-latest	npm	GitHub	Current balance and state for EVM, UTXO, Solana, XRP, Kaspa addresses
@cryptoapis-io/mcp-aml	npm	GitHub	AML address verification and transaction screening
@cryptoapis-io/mcp-address-history	npm	GitHub	Full transaction and token history for synced addresses
@cryptoapis-io/mcp-block-data	npm	GitHub	Block details by height or hash (EVM, UTXO, XRP)
@cryptoapis-io/mcp-blockchain-events	npm	GitHub	Webhook subscriptions for on-chain events
@cryptoapis-io/mcp-blockchain-fees	npm	GitHub	Fee recommendations and gas estimation (EVM, UTXO, XRP)
@cryptoapis-io/mcp-broadcast	npm	GitHub	Broadcast signed raw transactions
@cryptoapis-io/mcp-contracts	npm	GitHub	Token details by contract address (EVM, Solana)
@cryptoapis-io/mcp-hd-wallet	npm	GitHub	HD wallet management, balance, and sync (EVM, UTXO, XRP)
@cryptoapis-io/mcp-market-data	npm	GitHub	Asset prices, exchange rates, and market metadata
@cryptoapis-io/mcp-prepare-transactions	npm	GitHub	Build unsigned EVM transactions
@cryptoapis-io/mcp-signer	npm	GitHub	Local transaction signing (EVM, UTXO, Tron, XRP, Kaspa, Solana, Tezos) — no API calls
@cryptoapis-io/mcp-simulate	npm	GitHub	Dry-run EVM transaction simulation
@cryptoapis-io/mcp-transactions-data	npm	GitHub	Transaction lookup by hash (EVM, UTXO, Solana, XRP, Kaspa)
@cryptoapis-io/mcp-utils	npm	GitHub	Address validation, raw tx decoding, XRP X-Address encoding
@cryptoapis-io/mcp-shared	npm	GitHub	Shared HTTP client, error types, blockchain constants, and schemas

Supported Blockchains & Networks

EVM

Blockchain	Mainnet	Testnet
Ethereum	mainnet	sepolia
Ethereum Classic	mainnet	mordor
Binance Smart Chain	mainnet	testnet
Polygon	mainnet	amoy
Avalanche (C-Chain)	mainnet	fuji
Tron	mainnet	nile
Arbitrum	mainnet	sepolia
Base	mainnet	sepolia
Optimism	mainnet	sepolia

UTXO

Blockchain	Mainnet	Testnet
Bitcoin	mainnet	testnet
Bitcoin Cash	mainnet	testnet
Litecoin	mainnet	testnet
Dogecoin	mainnet	testnet
Dash	mainnet	testnet
Zcash	mainnet	testnet

Other

Blockchain	Mainnet	Testnet
XRP (Ripple)	mainnet	testnet
Solana	mainnet	devnet
Kaspa	mainnet	—

Configuration

All MCP servers need a Crypto APIs API key. For stdio transport, provide it at startup via CLI argument or environment variable. For HTTP transport, it can also be provided per-request via x-api-key header (see HTTP API Key Modes).

# CLI argument (recommended)
npx @cryptoapis-io/mcp-address-latest --api-key YOUR_API_KEY

# Environment variable
export CRYPTOAPIS_API_KEY=YOUR_API_KEY
npx @cryptoapis-io/mcp-address-latest

Claude Desktop

Add to your Claude Desktop config:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "cryptoapis-address-latest": {
      "command": "npx",
      "args": ["-y", "@cryptoapis-io/mcp-address-latest"],
      "env": {
        "CRYPTOAPIS_API_KEY": "your_api_key_here"
      }
    },
    "cryptoapis-hd-wallet": {
      "command": "npx",
      "args": ["-y", "@cryptoapis-io/mcp-hd-wallet"],
      "env": {
        "CRYPTOAPIS_API_KEY": "your_api_key_here"
      }
    }
  }
}

Add as many servers as you need. See each package's README for its specific config.

Cursor

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

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

Claude Code

claude mcp add cryptoapis-address-latest -- npx -y @cryptoapis-io/mcp-address-latest --api-key YOUR_API_KEY

n8n

n8n's AI Agent can call your MCP servers using the built-in MCP Client Tool node. This lets you use blockchain data tools inside n8n workflows — no custom code needed.

1. Start a server in HTTP mode:

npx @cryptoapis-io/mcp-market-data --transport http --api-key YOUR_API_KEY

2. Add the MCP Client Tool to your n8n workflow:

1. Create or open a workflow with an AI Agent node
2. Under the agent's Tools section, click Add Tool > MCP Client Tool
3. Configure the MCP Client Tool:
   • URL: http://localhost:3000/mcp (or your server's host/port)
4. The agent now has access to all tools exposed by that MCP server

3. Repeat for additional servers (each on a different port):

npx @cryptoapis-io/mcp-blockchain-fees --transport http --port 3001 --api-key YOUR_API_KEY
npx @cryptoapis-io/mcp-transactions-data --transport http --port 3002 --api-key YOUR_API_KEY

Add a separate MCP Client Tool node for each server, pointing to its port.

Note: All servers default to port 3000. When running multiple servers on the same host, use --port to assign each a different port.

Tip: For production use, run the servers as persistent processes (e.g. via pm2, systemd, or Docker) rather than npx.

Note: @cryptoapis-io/mcp-signer only supports stdio transport and cannot be used with n8n's HTTP-based MCP Client Tool.

There is also a dedicated n8n community node that provides native Crypto APIs integration within n8n workflows and AI agents.

CLI Arguments

All servers support these arguments:

Argument	Description	Default
--api-key	Crypto APIs API key	CRYPTOAPIS_API_KEY env var
--transport	Transport type: stdio or http	stdio
--host	HTTP host (use 0.0.0.0 to accept remote connections — requires an auth token with --api-key)	127.0.0.1
--auth-token	Bearer token callers must send (Authorization: Bearer <token>); prefer the env var	MCP_AUTH_TOKEN env var
--allowed-hosts	Comma-separated Host header allowlist for non-loopback binds	—
--port	HTTP port	3000
--path	HTTP path	/mcp
--stateless	Enable stateless HTTP mode	false

Exception: @cryptoapis-io/mcp-signer only supports stdio (no HTTP transport) since it handles private keys locally.

HTTP API Key Modes

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

Fixed key (single-tenant) — start with --api-key. The key is used for all requests and any x-api-key headers on incoming requests are ignored.

npx @cryptoapis-io/mcp-market-data --transport http --api-key YOUR_API_KEY

Per-request key (multi-tenant) — start without --api-key. Each incoming HTTP request must include an x-api-key header with a valid Crypto APIs key. This enables hosting a single public MCP server that serves multiple users, each using their own API key.

# Start without API key
npx @cryptoapis-io/mcp-market-data --transport http

# Clients include their key in every request via x-api-key header

Scenario	API key source	x-api-key header
Stdio (always)	--api-key or CRYPTOAPIS_API_KEY env var (required)	N/A
HTTP with --api-key	Startup key (fixed for all requests)	Ignored
HTTP without --api-key	x-api-key request header (required)	Required

Exposing the server beyond localhost

HTTP mode listens on 127.0.0.1 by default, so only processes on the same machine can reach it. To accept connections from other machines or containers (Docker, Kubernetes, a shared VPC), bind explicitly and protect the port:

# Fixed key: callers must present a bearer token. Without MCP_AUTH_TOKEN the server refuses to
# start on a non-loopback address, because anyone reaching the port would spend your credits.
export MCP_AUTH_TOKEN=$(openssl rand -hex 32)
npx @cryptoapis-io/mcp-market-data --transport http --host 0.0.0.0 --api-key YOUR_API_KEY \
  --allowed-hosts mcp.internal.example
# Clients send: Authorization: Bearer $MCP_AUTH_TOKEN

# Per-request key: no startup key; requests without their own x-api-key are rejected (401)
npx @cryptoapis-io/mcp-market-data --transport http --host 0.0.0.0

--allowed-hosts restricts the Host header (DNS rebinding protection) when not bound to loopback; loopback binds get this check automatically. Prefer MCP_AUTH_TOKEN over --auth-token: command-line arguments are visible in the process list.

Note: Stdio transport always requires an API key at startup. The per-request mode only applies to HTTP transport.

Testing with MCP Inspector

npx @modelcontextprotocol/inspector npx @cryptoapis-io/mcp-address-latest --api-key YOUR_API_KEY

Important: API Key Required

Warning: Making requests without a valid API key — or with an incorrect one — may result in your IP being banned from the Crypto APIs ecosystem. Always ensure a valid API key is configured before starting any server.

Security

Found a vulnerability? Please report it privately, not in a public issue. See SECURITY.md or email security@cryptoapis.io. Published advisories are on the Security tab.

License

MIT