What can you do with this server?

This MCP server builds unsigned cryptocurrency transactions across multiple blockchains for local signing and broadcasting, and provides Crypto APIs reference documentation. * Prepare unsigned EVM transactions: native coin transfers, ERC-20 fungible token transfers, and ERC-721 NFT transfers. * Prepare unsigned Tezos operations: native XTZ transfers, FA1.2 token transfers, and FA2 token transfers. * Prepare unsigned Solana transactions: native SOL transfers and SPL token transfers. * Prepare unsigned Kaspa transactions: native KAS transfers with multi-recipient support. * Prepare unsigned XRP transactions: native XRP transfers. * Prepare unsigned UTXO transactions: native coin transfers for Bitcoin, Bitcoin Cash, Litecoin, Dogecoin, Dash, and Zcash with multi-recipient support. * Prepare unsigned Tron transactions: native TRX transfers, TRC-20 token transfers, and TRC-721/TRC-1155 NFT transfers. * Access Crypto APIs reference documentation: supported blockchains, error codes, credit costs, callback/webhook mechanics, and rate limits. * Returns unsigned transaction data ready for local signing and subsequent broadcast via broadcast_signed_transaction.

Which integrations are available for this server?

Allows using the Crypto APIs Prepare Transactions MCP server as a tool within n8n workflows to prepare unsigned EVM transactions for native coin, ERC-20 token, and ERC-721 NFT transfers.

How do I use @cryptoapis-io/mcp-prepare-transactions?

1. Click on "Deploy Server". 2. Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state. 3. In the chat, type @ followed by the MCP server name and your instructions, e.g., "@@cryptoapis-io/mcp-prepare-transactions Prepare an unsigned native coin transfer of 0.1 ETH to 0xRecipientAddress" That's it! The server will respond to your query, and you can continue using it as needed. Here is a step-by-step guide with screenshots.

@cryptoapis-io/mcp-prepare-transactions

Official

by CryptoAPIs-io

Overview Schema Source Related Servers Discussions Admin

TypeScript

Hybrid

@cryptoapis-io/mcp-prepare-transactions

MCP server for Crypto APIs Prepare Transactions product. Build unsigned transactions for EVM, Tezos, Solana, Kaspa, XRP, UTXO, and Tron.

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

Features

Prepare EVM native coin, ERC-20 fungible token, and ERC-721 NFT transfer transactions
Prepare native Tezos (XTZ), FA1.2, and FA2 token transfer operations
Prepare native SOL and SPL token transfer transactions on Solana
Prepare native KAS transfers on Kaspa, with multi-recipient support
Prepare native XRP transfers
Prepare native coin transfers across 6 UTXO chains (Bitcoin, Bitcoin Cash, Litecoin, Dogecoin, Dash, Zcash)
Prepare native TRX, TRC-20, and NFT transfers via Tron's dedicated prepare-transactions endpoints
Returns unsigned transaction data ready for local signing

Related MCP server: @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 (listens on 127.0.0.1; see "Exposing the server beyond localhost")
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/claude_desktop_config.json on macOS, %APPDATA%\Claude\claude_desktop_config.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

Start the server in HTTP mode:

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

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

n8n in Docker: localhost inside the container is not your machine. Start the server with --host 0.0.0.0 and MCP_AUTH_TOKEN set (see Exposing the server beyond localhost), use http://host.docker.internal:3000/mcp as the URL, and add an Authorization: Bearer <token> header to the MCP Client Tool credential.

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

Available Tools

`prepare_transactions_evm`

Prepare unsigned EVM transactions.

Action	Description
`prepare-transaction-from-address`	Prepare a native coin transfer from an address
`prepare-fungible-token-transfer`	Prepare an ERC-20 token transfer
`prepare-nft-transfer`	Prepare an ERC-721 NFT transfer

`prepare_transactions_tezos`

Prepare unsigned Tezos operations (mainnet, shadownet).

Action	Description
`native-coins`	Prepare a native XTZ transfer
`fa1-2-tokens`	Prepare an FA1.2 token transfer
`fa2-tokens`	Prepare an FA2 token transfer

`prepare_transactions_solana`

Prepare unsigned Solana transactions (mainnet, devnet).

Action	Description
`native-coins`	Prepare a native SOL transfer
`spl-tokens`	Prepare an SPL token transfer

`prepare_transactions_kaspa`

Prepare unsigned Kaspa transactions (mainnet only).

Action	Description
`native-coins`	Prepare a native KAS transfer, supporting multiple recipients in one transaction

`prepare_transactions_xrp`

Prepare unsigned XRP transactions (mainnet, testnet).

Action	Description
`native-coins`	Prepare a native XRP transfer

`prepare_transactions_utxo`

Prepare unsigned UTXO transactions (Bitcoin, Bitcoin Cash, Litecoin, Dogecoin, Dash, Zcash; mainnet, testnet).

Action	Description
`native-coins`	Prepare a native coin transfer, supporting multiple recipients. Requires `feePriority` or `exactFee`

`prepare_transactions_tron`

Prepare unsigned Tron transactions via Tron's dedicated prepare-transactions endpoints (mainnet, nile).

Action	Description
`native-coins`	Prepare a native TRX transfer
`trc20-tokens`	Prepare a TRC-20 token transfer
`non-fungible-tokens`	Prepare a TRC-721/TRC-1155 NFT transfer

CLI 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 `MCP_AUTH_TOKEN` 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`

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

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, bind explicitly and protect the port:

# Startup-key mode: callers must present the token (the server refuses to start without one)
export MCP_AUTH_TOKEN=$(openssl rand -hex 32)
npx @cryptoapis-io/mcp-prepare-transactions --transport http --host 0.0.0.0 --port 3000 --api-key YOUR_API_KEY \
  --allowed-hosts mcp.internal.example
# Clients send: Authorization: Bearer $MCP_AUTH_TOKEN

# Per-request key mode: no startup key, every request must carry the caller's own x-api-key
npx @cryptoapis-io/mcp-prepare-transactions --transport http --host 0.0.0.0 --port 3000

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

Stdio transport always requires an API key at startup.

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.

Remote MCP Server

Crypto APIs provides an official remote MCP server with all tools available via HTTP Streamable transport at https://ai.cryptoapis.io/mcp. Pass your API key via the x-api-key header — no installation required.

License

MIT

Available Tools

8 tools

prepare_transactions_evmA

Build unsigned EVM transactions ready for signing. Returns the raw unsigned transaction hex and fee details. After preparing, use a signing tool (e.g. evm_sign) to sign locally, then broadcast via broadcast_signed_transaction.

Actions: • prepare-transaction-from-address: Build an unsigned native coin transfer (e.g. ETH, BNB) • prepare-fungible-token-transfer: Build an unsigned ERC-20 token transfer • prepare-nft-transfer: Build an unsigned ERC-721 NFT transfer

Credits by action (source: OpenAPI): • prepare-fungible-token-transfer: 24 • prepare-nft-transfer: 24 • prepare-transaction-from-address: 24