Project Structure

Setup

Project Structure

Open LangGraph Server integrates seamlessly into your existing JavaScript/TypeScript projects. While it's flexible about how you organize your code, following a consistent structure makes your project maintainable and easy to navigate.

This guide shows recommended folder structures for different frameworks and project types.

Hono.js Projects

For lightweight API servers with Hono.js, we recommend this structure:

my-hono-app/
├── src/
│   ├── agent/
│   │   ├── graph.ts              # Your LangGraph definition
│   │   ├── index.ts              # Graph registration
│   │   └── types.ts              # Type definitions
│   ├── routes/
│   │   ├── auth.ts               # Authentication routes
│   │   └── files.ts              # File handling routes
│   ├── lib/
│   │   ├── auth.ts               # Authentication utilities
│   │   └── validation.ts         # Input validation
│   └── app.ts                    # Main Hono application
├── .env                          # Environment variables
├── package.json
├── tsconfig.json
└── studio.ts                     # Optional: Studio configuration

Key Files

File/Folder	Description
`src/agent/graph.ts`	Your main LangGraph workflow definition
`src/agent/index.ts`	Graph registration and export
`src/app.ts`	Hono application setup with middleware
`src/routes/`	Additional API routes beyond LangGraph
`studio.ts`	Studio configuration for testing (optional)

Next.js Projects

For full-stack applications with Next.js:

my-nextjs-app/
├── app/
│   ├── api/
│   │   └── langgraph/
│   │       └── [...path]/
│   │           └── route.ts        # LangGraph API routes
│   ├── layout.tsx
│   └── page.tsx
├── agent/
│   ├── graph.ts                   # LangGraph definition
│   ├── index.ts                   # Graph registration
│   └── state.ts                   # Graph state types
├── lib/
│   ├── auth.ts                    # Authentication logic
│   └── utils.ts                   # Utility functions
├── .env.local                     # Environment variables
├── package.json
├── next.config.js
└── tsconfig.json

Key Files

File/Folder	Description
`app/api/langgraph/[...path]/route.ts`	Next.js API route handler for LangGraph
`agent/graph.ts`	Your LangGraph workflow
`agent/index.ts`	Graph registration for the API route

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