Grpc Invoke MCP server

gRPC Invoke MCP

grpc-invoke-mcp is an MCP server for calling gRPC methods from AI agents like Claude Code, Codex, Cursor, and other MCP-compatible tools.

It gives agents a simple way to inspect gRPC APIs and invoke unary RPCs using either server reflection or local .proto files. This is useful when you want an agent to explore services, understand request and response schemas, make real gRPC calls, and test gRPC integrations during agent-driven development without writing one-off scripts.

Features

• Call gRPC methods from MCP-compatible agents
• Describe gRPC services, methods, and message types
• Use server reflection or local .proto files
• Connect over TLS or plaintext HTTP/2
• Send custom metadata headers
• Pass JSON request bodies for unary RPCs
• Works with Claude Code, Codex, Cursor, and other MCP clients

Installation

Run the server with npx:

npx -y @grulex/grpc-invoke-mcp@latest

The package downloads a platform-specific grpc-invoke-mcp binary during installation.

Agent Setup

Claude Code

Project config file: .mcp.json

{
  "mcpServers": {
    "grpc-invoke": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@grulex/grpc-invoke-mcp@latest"]
    }
  }
}

Optional CLI setup:

claude mcp add --transport stdio grpc-invoke -- npx -y @grulex/grpc-invoke-mcp@latest

Codex

User config file: ~/.codex/config.toml

[mcp_servers.grpc-invoke]
command = "npx"
args = ["-y", "@grulex/grpc-invoke-mcp@latest"]

Optional CLI setup:

codex mcp add grpc-invoke -- npx -y @grulex/grpc-invoke-mcp@latest

Cursor

Project config file: .cursor/mcp.json

{
  "mcpServers": {
    "grpc-invoke": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@grulex/grpc-invoke-mcp@latest"]
    }
  }
}

You can also install it globally in ~/.cursor/mcp.json.

Available Tools

grpc_describe

Use this tool to inspect services, methods, and message types.

Common use cases:

• list services exposed by a gRPC server
• inspect a method signature before calling it
• explore message schemas through reflection
• describe APIs from local .proto files

grpc_call

Use this tool to invoke unary gRPC methods with a JSON request body.

Common use cases:

• call internal microservices from your agent
• test request and response payloads
• send auth headers or other gRPC metadata
• connect to local, staging, or production-safe endpoints

Example Prompts

• "Describe the services exposed by localhost:50051 using reflection."
• "Show the request schema for helloworld.Greeter/SayHello."
• "Call helloworld.Greeter/SayHello on localhost:50051 with { \"name\": \"World\" }."
• "Invoke package.Service/Method using protofiles and importpaths instead of reflection."

How It Works

This package exposes an MCP server over stdio. Your agent starts it locally and discovers tools such as:

• grpc_describe for schema inspection
• grpc_call for unary RPC invocation

Under the hood, the npm package launches a native grpc-invoke-mcp binary bundled at install time. The binary supports:

• gRPC server reflection
• local .proto definitions
• plaintext or TLS connections
• request metadata headers

Supported Platforms

The installer currently targets:

• macOS Apple Silicon
• macOS Intel
• Linux x64
• Linux ARM64
• Windows x64
• Windows ARM64

Troubleshooting

npx cannot start the server

Make sure Node.js and npx are installed and available in your PATH.

The binary download fails

The npm package downloads a release artifact during installation, so your machine needs network access to GitHub Releases.

Reflection does not work

Shortened. The full README is on GitHub.