LangFlow

A modern AI workflow automation app built with Next.js 15, React 19, Prisma, and PostgreSQL. Design and run workflows, manage triggers and actions, and monitor executions with a beautiful, responsive UI.

Stripe billing has been disabled and fully removed from the frontend. Paid plan UI remains for demonstration and links to Contact Sales.

Tech Stack

• Next.js 15 (App Router)
• React 19
• TypeScript
• Prisma ORM (PostgreSQL)
• NextAuth for authentication
• Tailwind CSS 4
• Radix UI components

Monorepo Layout

LangFlow/
├─ frontend/                  # Next.js app
│  ├─ prisma/                 # Prisma schema & migrations (frontend DB)
│  ├─ src/
│  │  ├─ app/                 # Next.js app router routes
│  │  │  ├─ api/              # API routes
│  │  │  │  ├─ actions/       # Example action endpoints
│  │  │  │  ├─ hooks/         # Webhook catch endpoints
│  │  │  │  ├─ stripe/        # Stubbed billing endpoints (disabled)
│  │  │  │  └─ workflows/     # Workflow APIs
│  │  │  ├─ (pages...)        # UI routes (dashboard, pricing, etc.)
│  │  ├─ components/          # UI components
│  │  ├─ lib/                 # Server-side utilities (auth, prisma, etc.)
│  │  └─ styles/              # Global styles
│  ├─ package.json
│  └─ tsconfig.json
└─ hooks/                     # Server-side workflow engine package
   ├─ prisma/                 # Prisma schema & migrations (hooks DB)
   ├─ src/
   │  ├─ workflow-engine.ts   # Core engine
   │  └─ index.ts             # Exports
   ├─ package.json
   └─ tsconfig.json

Prerequisites

• Node.js 18+
• PostgreSQL database

Environment Variables

Create a .env file under frontend/ with:

# Database
DATABASE_URL=postgresql://USER:PASSWORD@HOST:PORT/DB_NAME

# NextAuth
NEXTAUTH_URL=http://localhost:3000
NEXTAUTH_SECRET=your-strong-random-secret

# App
APP_URL=http://localhost:3000

Stripe keys are not needed because billing is disabled.

Getting Started

1. Install dependencies

# From repo root (recommended)
npm install --workspaces

# Or install inside each package
cd frontend && npm install
cd ../hooks && npm install

2. Generate Prisma client and run migrations

# Frontend database
cd frontend
npm run prisma:generate  # or `npx prisma generate`
npx prisma migrate deploy

3. Seed (optional)

npm run seed

4. Run the dev server

npm run dev
# App at http://localhost:3000

Useful Scripts (frontend/package.json)

• dev: start Next.js dev server
• build: prisma generate + next build
• start: start Next.js in production mode
• lint: next lint
• seed: run prisma/seed.ts
• vercel-build: prisma generate + prisma migrate deploy + next build

Database & Prisma

• Prisma schema: frontend/prisma/schema.prisma
• Generate client: npx prisma generate
• Migrate (prod): npx prisma migrate deploy
• Migrate (dev): npx prisma migrate dev --name <migration_name>

The hooks/ package also has a Prisma schema for workflow engine–related data. If you use that package separately, configure its .env and migrations similarly.

Authentication

• NextAuth is configured in frontend/src/lib/auth.ts and app/api/auth/[...nextauth]/route.ts
• Default providers include email/password (via custom endpoints) and can be extended

API Routes Overview

• app/api/workflows and app/api/workflows/[id] manage workflows
• app/api/actions/send-gmail demonstrates a sample action
• app/api/hooks/catch/[userId]/[workflowId] receives workflow events
• app/api/stripe/* are stubs returning disabled responses

Billing (Disabled)

• All Stripe client code is removed/stubbed.
• Pricing page shows "Contact Sales" for paid plans.
• To re-enable billing later, reintroduce the Stripe SDK, API routes, and environment variables.

Development Notes

• React Server Components (RSC) + App Router are used; keep server-only code in src/lib/ and API routes.
• Components that use hooks like useSession must be client components ('use client').
• Keep Prisma client as a singleton to avoid hot-reload issues (see src/lib/prisma.ts).

Deployment

• The project is ready for platforms like Vercel.
• On deploy, ensure the following are set:
  • DATABASE_URL
  • NEXTAUTH_URL
  • NEXTAUTH_SECRET
  • APP_URL
• Billing keys (Stripe) are not required.

Troubleshooting

• Migration errors: ensure your DATABASE_URL is correct and the database is reachable.
• TypeScript build failures: check for stale imports after enabling/disabling features.
• NextAuth callback URLs: ensure NEXTAUTH_URL matches your deployed origin.

Made with love by Alok Dangre