mcp-ws.js•6.55 kB
"use strict";
/**
* Simple HTTP-based MCP server for Claude Web
* Following MCP spec more strictly
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.default = handler;
async function handler(req, res) {
// Set CORS headers
res.setHeader('Access-Control-Allow-Origin', '*');
res.setHeader('Access-Control-Allow-Methods', 'POST, OPTIONS');
res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
if (req.method === 'OPTIONS') {
return res.status(200).end();
}
if (req.method !== 'POST') {
return res.status(405).json({ error: 'Method not allowed' });
}
try {
const message = req.body;
// Initialize
if (message.method === 'initialize') {
return res.status(200).json({
jsonrpc: '2.0',
id: message.id,
result: {
protocolVersion: '2024-11-05',
capabilities: {
tools: {}
},
serverInfo: {
name: 'simple-mcp',
version: '1.0.0'
}
}
});
}
// List tools
if (message.method === 'tools/list') {
return res.status(200).json({
jsonrpc: '2.0',
id: message.id,
result: {
tools: [
{
name: 'get_time',
description: 'Get current time',
inputSchema: {
type: 'object',
properties: {},
required: []
}
},
{
name: 'echo',
description: 'Echo back the input',
inputSchema: {
type: 'object',
properties: {
message: {
type: 'string',
description: 'Message to echo'
}
},
required: ['message']
}
},
{
name: 'calculate',
description: 'Perform simple math calculation',
inputSchema: {
type: 'object',
properties: {
expression: {
type: 'string',
description: 'Math expression (e.g., 2+3*4)'
}
},
required: ['expression']
}
}
]
}
});
}
// Call tool
if (message.method === 'tools/call') {
const toolName = message.params?.name;
const args = message.params?.arguments || {};
if (toolName === 'get_time') {
return res.status(200).json({
jsonrpc: '2.0',
id: message.id,
result: {
content: [
{
type: 'text',
text: `🕐 Current time: ${new Date().toISOString()}`
}
]
}
});
}
if (toolName === 'echo') {
return res.status(200).json({
jsonrpc: '2.0',
id: message.id,
result: {
content: [
{
type: 'text',
text: `🔊 Echo: ${args.message || 'No message provided'}`
}
]
}
});
}
if (toolName === 'calculate') {
try {
const expression = args.expression;
if (!/^[0-9+\-*/.() ]+$/.test(expression)) {
throw new Error('Invalid characters');
}
const result = Function('"use strict"; return (' + expression + ')')();
return res.status(200).json({
jsonrpc: '2.0',
id: message.id,
result: {
content: [
{
type: 'text',
text: `🧮 ${expression} = ${result}`
}
]
}
});
}
catch (error) {
return res.status(200).json({
jsonrpc: '2.0',
id: message.id,
result: {
content: [
{
type: 'text',
text: `❌ Error calculating: ${args.expression}`
}
]
}
});
}
}
// Unknown tool
return res.status(200).json({
jsonrpc: '2.0',
id: message.id,
error: {
code: -32602,
message: `Unknown tool: ${toolName}`
}
});
}
// Unknown method
return res.status(200).json({
jsonrpc: '2.0',
id: message.id,
error: {
code: -32601,
message: `Method not found: ${message.method}`
}
});
}
catch (error) {
return res.status(200).json({
jsonrpc: '2.0',
id: null,
error: {
code: -32700,
message: 'Parse error'
}
});
}
}