#!/usr/bin/env tsx
import * as readline from 'readline'
class MinimalMCPHandler {
async handleRequest(request: any) {
const validationResult = this.validateRequest(request)
if (!validationResult.isValid) {
return this.createErrorResponse(request?.id ?? 0, validationResult.error)
}
const mcpRequest = request
try {
switch (mcpRequest.method) {
case 'initialize':
const initializeResult = {
protocolVersion: '2024-11-05',
capabilities: {
tools: { listChanged: true },
resources: { subscribe: true, listChanged: true },
prompts: { listChanged: true }
},
serverInfo: {
name: 'minimal-test-server',
version: '1.0.0'
}
}
return this.createResponse(mcpRequest.id, initializeResult)
case 'tools/list':
return this.createResponse(mcpRequest.id, {
tools: [
{
name: 'test_tool',
description: 'Simple test tool',
inputSchema: {
type: 'object',
properties: {
message: { type: 'string', description: 'Test message' }
}
}
}
]
})
case 'tools/call':
const { name, arguments: args } = mcpRequest.params || {}
return await this.handleToolCall(name, args, mcpRequest.id)
default:
return this.createErrorResponse(mcpRequest.id, {
code: -32601,
message: 'Method not found'
})
}
}
catch (error) {
return this.createErrorResponse(mcpRequest.id, {
code: -32603,
message: 'Internal error',
data: error instanceof Error ? error.message : 'Unknown error'
})
}
}
async handleToolCall(toolName: string, args: any, requestId: any) {
try {
switch (toolName) {
case 'test_tool':
return this.createResponse(requestId, {
content: [
{
type: 'text',
text: `Test successful! Message: ${args?.message || 'No message provided'}`
}
]
})
default:
return this.createErrorResponse(requestId, {
code: -32601,
message: `Unknown tool: ${toolName}`
})
}
}
catch (error) {
return this.createErrorResponse(requestId, {
code: -32603,
message: `Tool execution failed: ${error instanceof Error ? error.message : 'Unknown error'}`
})
}
}
validateRequest(request: any) {
if (!request || typeof request !== 'object' || Array.isArray(request)) {
return {
isValid: false,
error: {
code: -32600,
message: 'Invalid Request'
}
}
}
if (request.jsonrpc !== '2.0') {
return {
isValid: false,
error: {
code: -32600,
message: 'Invalid Request'
}
}
}
if (!('id' in request)) {
return {
isValid: false,
error: {
code: -32600,
message: 'Invalid Request'
}
}
}
if (!request.method) {
return {
isValid: false,
error: {
code: -32600,
message: 'Invalid Request'
}
}
}
return {
isValid: true
}
}
createResponse(id: any, result: any) {
return {
jsonrpc: '2.0',
id,
result
}
}
createErrorResponse(id: any, error: any) {
return {
jsonrpc: '2.0',
id: id === null ? 0 : id,
error
}
}
}
const handler = new MinimalMCPHandler()
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
terminal: false
})
rl.on('line', async (line: string) => {
try {
const request = JSON.parse(line.trim())
const response = await handler.handleRequest(request)
console.log(JSON.stringify(response))
} catch (error) {
const errorResponse = {
jsonrpc: '2.0',
id: null,
error: {
code: -32700,
message: 'Parse error'
}
}
console.log(JSON.stringify(errorResponse))
}
})
process.on('SIGINT', () => {
rl.close()
process.exit(0)
})
process.on('SIGTERM', () => {
rl.close()
process.exit(0)
})
