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日本語

grpc-mcp

grpc-mcp is an MCP server built with Node.js/TypeScript. It enables easy gRPC requests and Protocol Buffer file information retrieval.

Features

Retrieve service/method info from Protocol Buffer files
Send requests to gRPC servers (with SSL, timeout, headers, etc.)
Get response time statistics
Operate via natural language from MCP clients or VSCode extensions

Related MCP server: MCP-Grep

Limitations

This tool does NOT support gRPC streaming (server streaming, client streaming, or bidirectional streaming). Only single-request single-response (unary) RPCs are supported.

AI instruction prompts

This repository includes prompt templates to instruct AI agents using natural language. The templates and usage examples help automate gRPC requests and Protocol Buffer handling. See the prompt files below:

English: grpc-mcp.prompt.md
Japanese: grpc-mcp.ja.prompt.md

Usage

MCP Client Example

use npx.

{ "servers": { "grpc-mcp-sample": { "type": "stdio", "command": "npx", "args": ["-y", "grpc-mcp"] } } }

or use install module.

{ "servers": { "grpc-mcp-sample": { "type": "stdio", "command": "node", "args": ["C:~\\node_modules\\grpc-mcp\\dist\\index.js"] } } }

Start Server

node C:~\node_modules\grpc-mcp\dist\index.js

Dependencies

@grpc/grpc-js
@grpc/proto-loader
fastmcp
zod

MCP Tool Basic Operations

1. Load Proto Files

Specify the directory containing proto files to get service/method info.

{ "tool": "loadProto", "parameters": { "dir": "C:\\Users\\proto" } }

2. Get Method Information

Specify service/method to get request/response structure.

{ "tool": "getMethodInformation", "parameters": { "path": "C:\\Users\\proto\\your.proto", "service": "YourService", "method": "YourMethod" } }

3. Send gRPC Request

Specify proto, service, method, request body, SSL, timeout, etc.

{ "tool": "sendRequest", "parameters": { "path": "C:\\Users\\proto\\your.proto", "address": "localhost:6565", "service": "YourService", "method": "YourMethod", "body": "{\"key\": \"value\"}", "config": { "SSL": false, // true: enabled, false: disabled "deadLine": 1000 // milliseconds } } }

Response Example

{ "analyze": { "time": 123 // response time (ms) }, "response": { "ok": true, "body": "{...}" // response body (JSON string) // on failure: // "ok": false, // "error": { "code": 14, "details": "UNAVAILABLE" } } }

License

MIT

MCP Tool Usage Examples

Natural Language Usage Examples

Send gRPC request
- e.g. "Set id:123 in the request and call GetUser method of User service"
Multiple requests/statistics
- e.g. "Call GetUser of Hoge service 10 times and show average/max/min response time"
Summarize/extract response
- e.g. "Summarize user list in GetUser response"
- e.g. "Show only error details if failed"
Get method info
- e.g. "Show request/response structure for Sample method of Sample service in sample.proto"

For Developers

Setup & Build

npm install npm run build

Lint & Format

npm run lint npm run prettier:write

Example Implementation

// Import loader and client from grpc-mcp library import { loader, client } from "grpc-mcp"; async function main() { // Load proto files from the proto directory const protoList = await loader.loadAsync("./proto/"); const proto = protoList[0]; const service = proto.services[0]; const method = service.methods[0]; // Get method information and print it const info = await loader.getMethodAsync(proto.path, service.name, method); console.log(info); // Send a gRPC request and print the response const response = await client.requestAsync({ path: proto.path, address: "localhost:6565", service: service.name, method: method, body: JSON.stringify({ key: "value" }), config: { SSL: false }, }); console.log(response); } main();

gRPC MCP Server