io.github.CryptoAPIs-io/mcp-broadcast
MCP server for broadcasting signed raw transactions to multiple blockchains via Crypto APIs
Open source Open in the app JSON README (API)
About
MCP server for broadcasting signed raw transactions to multiple blockchains via Crypto APIs
Details
- Kind
- MCP servers
- Topic
- Finance & crypto
- Publisher
- cryptoapis-io
- Origin
- official
- Category
- ferramentas
- Transport
- local
- Version
- 0.4.0
- Last push
- 2026-07-30T05:49:51Z
- Repository state
- ativo
- Language
- TypeScript
- Added
- 2026-08-29 03:01:48
- Updated
- 2026-08-29 03:01:48
- Origin id
io.github.CryptoAPIs-io/mcp-broadcast
README
# @cryptoapis-io/mcp-broadcast
MCP server for [Crypto APIs](https://cryptoapis.io/) Broadcast product. Submit locally signed transactions to the blockchain.
> **API Version:** Compatible with Crypto APIs version **2024-12-12**
## Features
- Broadcast signed transaction hex to any supported blockchain
- Supports EVM (Ethereum, Ethereum Classic, BSC, Polygon, Avalanche (C-Chain), Arbitrum, Base, Optimism, Tron)
- Supports UTXO (Bitcoin, Bitcoin Cash, Litecoin, Dogecoin, Dash, Zcash)
- Works with transactions signed by `@cryptoapis-io/mcp-signer` or any external signer
## Prerequisites
- Node.js 18+
- [Crypto APIs](https://cryptoapis.io/) account and API key ([sign up](https://app.cryptoapis.io/signup) | [get API key](https://app.cryptoapis.io/api-keys))
## Installation
```bash
npm install @cryptoapis-io/mcp-broadcast
```
Or install all Crypto APIs MCP servers: `npm install @cryptoapis-io/mcp`
## Usage
```bash
# Run with API key
npx @cryptoapis-io/mcp-broadcast --api-key YOUR_API_KEY
# Or use environment variable
export CRYPTOAPIS_API_KEY=YOUR_API_KEY
npx @cryptoapis-io/mcp-broadcast
# HTTP transport
npx @cryptoapis-io/mcp-broadcast --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):
```json
{
"mcpServers": {
"cryptoapis-broadcast": {
"command": "npx",
"args": ["-y", "@cryptoapis-io/mcp-broadcast"],
"env": {
"CRYPTOAPIS_API_KEY": "your_api_key_here"
}
}
}
}
```
### Cursor
Add to `.cursor/mcp.json` (project) or `~/.cursor/mcp.json` (global):
```json
{
"mcpServers": {
"cryptoapis-broadcast": {
"command": "npx",
"args": ["-y", "@cryptoapis-io/mcp-broadcast"],
"env": {
"CRYPTOAPIS_API_KEY": "your_api_key_here"
}
}
}
}
```
### MCP Inspector
```bash
npx @modelcontextprotocol/inspector npx @cryptoapis-io/mcp-broadcast --api-key YOUR_API_KEY
```
### n8n
1. Start the server in HTTP mode:
```bash
npx @cryptoapis-io/mcp-broadcast --transport http --port 3000 --api-key YOUR_API_KEY
```
2. In your n8n workflow, add an **AI Agent** node
3. 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
### `broadcast_signed_transaction`
Submit a signed transaction to the blockchain.
| Parameter | Description |
|-----------|-------------|
| `blockchain` | Target blockchain (ethereum, bitcoin, binance-smart-chain, tron, polygon, etc.) |
| `network` | Network (mainnet, testnet, sepolia, mordor, nile, amoy, fuji, etc.) |
| `signedTransactionHex` | The signed transaction hex string to broadcast |
## 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 | `0.0.0.0` |
| `--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.
```bash
# Per-request key mode (multi-tenant)
npx @cryptoapis-io/mcp-broadcast --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
> **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](https://ai.cryptoapis.io/mcp). Pass your API key via the `x-api-key` header — no installation required.
## License
MIT