Multi-Agent

A Study Backend for Multi-Agent Systems, MCP, and Agentic Workflows

Environment Variables

Variable	Required	Description	Default
DATABASE_URL	No	SQL Database URL	postgres://admin:password@localhost:5432/backend_node
DATABASE_DIALECT	No	Database dialect	postgres
GOOGLE_CLIENT_ID	No	Google OAuth client ID
GOOGLE_CLIENT_SECRET	No	Google OAuth client secret
GOOGLE_CALLBACK_URL	No	Google OAuth callback URL
AUTH_REDIRECT_URL	No	Redirect URL after authentication
JWT_SECRET	Yes	Secret for signing JWT tokens
OPENAI_API_KEY	No	API key for OpenAI-compatible agent runtimes

Running the Application

Prerequisite: Node.js >= 18.18.0.

1. Install dependencies:

   npm install

2. Set environment variables for PostgreSQL and JWT. Configure the Google variables only if you also want to keep the OAuth flow enabled.

   To invoke supervisors and subagents through LangChain/LangGraph, also configure OPENAI_API_KEY or set llm_engine.config.api_key_env to the environment variable that stores the provider key.

   Or you can use a development PostgreSQL docker container with default values:

   docker run --name postgres-dev -e POSTGRES_DB=backend_node -e POSTGRES_USER=admin -e POSTGRES_PASSWORD=password -p 5432:5432 -d postgres

3. Start the application:

   npm start

WebSocket Chat (Supervisor)

Use ws://localhost:3000/ws/chat to chat in real-time with a supervisor thread.

• Authentication: send Authorization: Bearer <jwt> in the WebSocket handshake header.
• Fallback auth: ws://localhost:3000/ws/chat?token=<jwt>.
• Each message must target an existing thread created with target_type = supervisor.

Client event to send:

{
  "type": "user_message",
  "thread_id": "<thread-id>",
  "content": "Quero planejar uma viagem para Lisboa"
}

Server events:

• connected: handshake/auth succeeded.
• processing: the message was accepted and supervisor execution started.
• assistant_message: final supervisor answer for the thread.
• error: validation/runtime/auth errors.

Documentation

The API documentation is available at /api-docs when the application is running.

Contributing

Contributions are welcome! Please open an issue or submit a pull request.