Openrpc Mcp Server

Openrpc Mcp Server

What is Openrpc Mcp Server about?

Openrpc Mcp Server implements a Model Context Protocol (MCP) server that offers JSON‑RPC endpoints defined by an OpenRPC document. It enables clients to call arbitrary JSON‑RPC methods and discover the available methods on the server.

How to use Openrpc Mcp Server?

1. Installation – With Node.js installed, run npm install in the project directory or use the built‑in NPX command (see configuration below).
2. Running – Start the server via the NPX shortcut or by executing the built binary (npm run build). The server communicates over STDIO, making it compatible with Claude Desktop and other MCP clients.
3. CLI Tools –
   • rpc_call – Invoke any JSON‑RPC method by providing the server URL, method name, and parameters. Returns a JSON‑formatted result.
   • rpc_discover – Calls the OpenRPC rpc.discover method to list all methods exposed by the server.
4. Debugging – Run npm run inspector to launch the MCP Inspector, which supplies a web UI for tracing stdio communication.

Key features of Openrpc Mcp Server

• Full OpenRPC compliance with rpc.discover support.
• Two ready‑to‑use command‑line utilities (rpc_call, rpc_discover).
• Simple NPX‑based deployment; no global install required.
• Auto‑rebuild watch mode for development (npm run watch).
• Debugging integration via MCP Inspector.

Use cases of Openrpc Mcp Server

• Integrating custom JSON‑RPC services into Claude Desktop or other MCP‑compatible applications.
• Rapid prototyping of RPC APIs with automatic method discovery.
• Testing and debugging RPC interactions using the provided CLI tools.
• Building language‑model‑driven workflows that need to call external services via JSON‑RPC.

FAQ for Openrpc Mcp Server

Q: Do I need to install the package globally? A: No. Use the NPX command shown in the configuration; it fetches the latest version on demand.

Q: How does the server communicate with clients? A: Over standard input/output (stdio), which is the default transport for MCP servers.

Q: Can I customize environment variables? A: Yes. Include any required variables in the env section of the server configuration.

Q: What if I want to modify the OpenRPC schema? A: Edit the OpenRPC document in the source repository and rebuild the server (npm run build).

OpenRPC MCP Server

A Model Context Protocol (MCP) server that provides JSON-RPC functionality through OpenRPC.

https://github.com/user-attachments/assets/3447175a-f921-4ded-8250-b611edb2fb67

Features

Tools

• rpc_call - Call arbitrary JSON-RPC methods
  • Specify server URL, method name, and parameters
  • Returns JSON-formatted results
• rpc_discover - Discover available JSON-RPC methods
  • Uses OpenRPC's rpc.discover specification
  • Lists all methods on a given server

Development

Install dependencies:

npm install

Build the server:

npm run build

For development with auto-rebuild:

npm run watch

Installation

To use with Claude Desktop, add the server config:

On MacOS: ~/Library/Application Support/Claude/claude_desktop_config.json On Windows: %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "openrpc": {
      "command": "npx",
      "args": ["-y", "openrpc-mcp-server"]
    }
  }
}

Debugging

Since MCP servers communicate over stdio, debugging can be challenging. We recommend using the MCP Inspector:

npm run inspector

The Inspector will provide a URL to access debugging tools in your browser.