import express from "express";
import cors from 'cors';
import { randomUUID } from "node:crypto";
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js";
import { isInitializeRequest } from "@modelcontextprotocol/sdk/types.js"
import authenticationMiddleware from "./authenticationMiddleware";
import { z } from "zod";
const app = express();
app.use(express.json());
app.use(cors());
const transports: { [sessionId: string]: StreamableHTTPServerTransport } = {};
app.post('/mcp', authenticationMiddleware, async (req, res) => {
const sessionId = req.headers['mcp-session-id'] as string | undefined;
let transport: StreamableHTTPServerTransport;
if (sessionId && transports[sessionId]) {
transport = transports[sessionId];
} else if (!sessionId && isInitializeRequest(req.body)) {
transport = new StreamableHTTPServerTransport({
sessionIdGenerator: () => randomUUID(),
onsessioninitialized: (sessionId) => {
transports[sessionId] = transport;
}
});
transport.onclose = () => {
if (transport.sessionId) {
delete transports[transport.sessionId];
}
};
const server = new McpServer({
name: "procrastinator-mcp-server",
version: "1.0.0"
});
// Here's where we'll register our tools
server.tool(
'list_tasks',
{},
async (message, extra) => {
const userToken = extra?.authInfo?.token;
try {
const response = await fetch('https://procrastinator.test/api/tasks', {
headers: {
Authorization: `Bearer ${userToken}`,
'Content-Type': 'application/json',
'User-Agent': 'procrastinator-mcp/1.0.0',
'Accept': 'application/json',
}
})
if (! response.ok) {
return {
content: [
{
type: "text",
text: `Failed to list tasks: ${response.status} ${response.statusText}`
}
]
}
}
const tasks = await response.json();
if (tasks.length === 0) {
return {
content: [
{
type: "text",
text: "No tasks found."
}
]
};
}
const formattedTasks = tasks.data.map((task: any) => [
`ID: ${task.id}`,
`Title: ${task.title}`,
`Description: ${task.description || 'No description'}`,
`Completed At: ${task.completed_at ? new Date(task.completed_at).toLocaleString() : 'Not completed'}`,
].join('\n')
).join('\n');
return {
content: [
{
type: "text",
text: `Tasks:\n\n${formattedTasks}`
}
]
};
} catch (error) {
console.error('Error fetching tasks:', error);
return {
content: [
{
type: "text",
text: "Failed to fetch tasks due to an error."
}
]
};
}
}
)
server.tool(
'create_task',
{
title: z.string(),
description: z.string().optional(),
},
async (message, extra) => {
const userToken = extra?.authInfo?.token;
try {
const response = await fetch('https://procrastinator.test/api/tasks', {
method: 'POST',
headers: {
Authorization: `Bearer ${userToken}`,
'Content-Type': 'application/json',
'User-Agent': 'procrastinator-mcp/1.0.0',
'Accept': 'application/json',
},
body: JSON.stringify({
title: message.title,
description: message.description,
})
});
if (! response.ok) {
return {
content: [
{
type: "text",
text: `Failed to create task: ${response.status} ${response.statusText}`
}
]
};
}
const task = await response.json();
return {
content: [
{
type: "text",
text: `Task created successfully:\n\nID: ${task.data.id}\nTitle: ${task.data.title}\nDescription: ${task.data.description || 'No description'}\nCompleted At: ${task.data.completed_at ? new Date(task.data.completed_at).toLocaleString() : 'Not completed'}`
}
]
};
} catch (error) {
console.error('Error creating task:', error);
return {
content: [
{
type: "text",
text: "Failed to create task due to an error."
}
]
};
}
}
);
server.tool(
'update_task',
{
id: z.number(),
title: z.string(),
description: z.string(),
completed_at: z.string().regex(/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}$/, "Completed at must be in YYYY-MM-DD HH:ii:ss format").optional(),
},
async (message, extra) => {
const userToken = extra?.authInfo?.token;
try {
const response = await fetch(`https://procrastinator.test/api/tasks/${message.id}`, {
method: 'PUT',
headers: {
Authorization: `Bearer ${userToken}`,
'Content-Type': 'application/json',
'User-Agent': 'procrastinator-mcp/1.0.0',
'Accept': 'application/json',
},
body: JSON.stringify({
title: message.title,
description: message.description,
completed_at: message.completed_at ? message.completed_at : null,
})
})
if (! response.ok) {
return {
content: [
{
type: "text",
text: `Failed to update task: ${response.status} ${response.statusText}`
}
]
};
}
const task = await response.json();
return {
content: [
{
type: "text",
text: `Task updated successfully:\n\nID: ${task.data.id}\nTitle: ${task.data.title}\nDescription: ${task.data.description || 'No description'}\nCompleted At: ${task.data.completed_at ? new Date(task.data.completed_at).toLocaleString() : 'Not completed'}`
}
]
};
} catch (error) {
console.error('Error updating task:', error);
return {
content: [
{
type: "text",
text: "Failed to update task due to an error."
}
]
};
}
}
)
await server.connect(transport);
} else {
res.status(400).json({
jsonrpc: '2.0',
error: {
code: -32000,
message: 'Bad Request: No valid session ID provided',
},
id: null,
});
return;
}
await transport.handleRequest(req, res, req.body);
});
const handleSessionRequest = async (req: express.Request, res: express.Response) => {
const sessionId = req.headers['mcp-session-id'] as string | undefined;
if (!sessionId || !transports[sessionId]) {
res.status(400).send('Invalid or missing session ID');
return;
}
const transport = transports[sessionId];
await transport.handleRequest(req, res);
};
app.get('/mcp', handleSessionRequest);
app.delete('/mcp', handleSessionRequest);
app.get('/.well-known/oauth-protected-resource', (req, res) => {
res.json({
resource: 'http://localhost:3000',
authorization_servers: ['https://procrastinator.test'],
scopes_supported: [
'claudeai',
'tasks:create',
'tasks:update',
'tasks:delete',
'tasks:view',
],
bearer_methods_supported: ["header"],
introspection_endpoint: "none",
introspection_endpoint_auth_methods_supported: ["none"],
});
});
app.listen(3000);
