PromptLens is an open-source tool for comparing and analyzing LLM responses across different models using different models or different prompts

Features

• Prompt Discovery & Management

  • Dual prompt system with user and system prompts
  • Prompt history tracking
  • Continue conversations with selected or all models
  • Multi-turn conversations support

• LLM Integration

  • Support for OpenAI GPT & o1 models and Anthropic Claude
  • Streaming responses for real-time feedback
  • Cost calculation and usage tracking
  • API key management in settings
  • Model parameter configuration

• Results Display

  • Side-by-side comparison of responses
  • Syntax highlighting for code
  • Export and share functionality

Installation

Using Docker (Recommended)

The easiest way to get started is using Docker:

services:
  app:
    image: siteboonai/promptlens:latest
    ports:
      - "3000:3000"  # Application port (serves both frontend and API)
    environment:
      - OPENAI_KEY=your_key  # Optional can be configured in the settings later on
      - ANTHROPIC_KEY=your_key  # Optional can be configured in the settings later on
    volumes:
      - ./data:/app/data  # For SQLite database (stores prompts, comparisons, and encrypted API keys)

Save as docker-compose.yml and run:

docker-compose up -d

The application will be available at http://localhost:3000

Manual Installation

1. Clone the repository:

git clone https://github.com/siteboon/promptlens.git
cd promptlens

2. Install all dependencies:

npm run install:all

3. Configure environment:

   • Copy .env.example to .env
   • Add your OpenAI and/or Anthropic API keys (optional, can be configured in UI)

4. Start the application:

# Start both frontend and backend in development mode
npm run dev  # Frontend on port 3000, Backend on port 3001

# Or start them separately:
npm run dev:client  # Frontend on port 3000
npm run dev:server  # Backend on port 3001

This will initialize all packages in parallel and watch for changes, including the website which will be available at http://localhost:3000.

In development mode:

• Frontend: http://localhost:3000
• Backend API: http://localhost:3001

In production mode (Docker):

• Everything runs on http://localhost:3000 with API routes prefixed with /api

Key Endpoints

• POST /api/completions - Generate completions from LLM models
• GET /api/comparisons - List recent prompt comparisons
• GET /api/models - List available models
• POST /api/keys - Manage API keys
• GET /api/keys/info - Get API key status

Project Structure

promptlens-v2/
├── src/                    # Frontend source
│   ├── components/        # React components
│   ├── services/         # API and external services
│   ├── utils/           # Helper functions
│   └── assets/         # Static assets
├── server/              # Backend source
│   ├── src/
│   │   ├── migrations/  # Database migrations
│   │   └── index.ts    # Server entry point
│   └── package.json
├── public/             # Static files
└── package.json

Technology Stack

• Frontend

  • React with TypeScript
  • Tailwind CSS + DaisyUI
  • Vite build tool

• Backend

  • Node.js with TypeScript
  • SQLite database
  • Express server

Development & Contributing

We welcome contributions! Please see our Contributing Guide for details.

Documentation

• API Documentation - Details about the backend API
• Contributing Guide - How to contribute to the project

License

AGPL-3.0 - See LICENSE for details.