Listfix

AI-powered Facebook Marketplace listing optimizer.

Paste your listing → get an optimized title, description, price, and photo tips → sell faster.

What it does

1. You paste your Marketplace listing (title, description, price)
2. AI analyzes it against best practices
3. Returns: optimized title, improved description, suggested price, photo order, keywords, and tips
4. One-click copy the optimized text back to Marketplace

Quick Start

# Build
go build -o listfix .

# Run (demo mode — no API key needed)
./listfix

# Run with any OpenAI-compatible API
export OPENAI_API_KEY=your-key
./listfix

Open http://localhost:8080

Environment Variables

Variable	Required	Default	Description
OPENAI_API_KEY	No	—	API key for any OpenAI-compatible API. If not set, runs in demo mode with realistic mock data.
OPENAI_BASE_URL	No	https://api.openai.com/v1	API base URL. Works with OpenAI, Azure, Groq, Together, Ollama, LM Studio, vLLM, LiteLLM, or any OpenAI-compatible endpoint.
OPENAI_MODEL	No	gpt-4o-mini	Model name to use.
PORT	No	8080	HTTP server port.

Bring Your Own Key (BYOK): This tool does not include an API key. You bring your own key from any OpenAI-compatible provider. This keeps the project free, open source, and avoids shared-key rate limits.

Supported Providers

Works out of the box with any OpenAI-compatible API:

Provider	OPENAI_BASE_URL
OpenAI	https://api.openai.com/v1 (default)
Groq	https://api.groq.com/openai/v1
Together AI	https://api.together.xyz/v1
Ollama	http://localhost:11434/v1
LM Studio	http://localhost:1234/v1
vLLM	http://localhost:8000/v1
LiteLLM	http://localhost:4000/v1
Azure OpenAI	https://{resource}.openai.azure.com/openai/deployments/{deploy}/v1

API

POST /api/optimize

Optimize a marketplace listing.

Request:

{
  "listing_text": "Selling my iPhone 14 Pro, used for 6 months, works perfectly, comes with case and charger. Asking $750 OBO."
}

Response:

{
  "score": 42,
  "title": {
    "current": "Selling my iPhone 14 Pro...",
    "score": 35,
    "optimized": "iPhone 14 Pro - Excellent Condition - Local Pickup",
    "keywords_added": ["condition", "brand", "dimensions"]
  },
  "description": {
    "current": "...",
    "score": 30,
    "optimized": "...with added dimensions, condition details, and call-to-action",
    "improvements": ["Added specific dimensions", "Included brand name", "Added condition details"]
  },
  "pricing": {
    "current": 750,
    "suggested": 675,
    "analysis": "Your price is slightly above market average.",
    "comparable_range": "$525-$825"
  },
  "photos": {
    "current_lead": 1,
    "suggested_lead": 3,
    "reason": "Photo #3 shows the full item with good lighting"
  },
  "keywords": ["like new", "barely used", "must go", "obo", "local pickup"],
  "tips": [
    "Move your best-lit photo to the first position",
    "Add exact dimensions (L x W x H)",
    "Include the brand name in the title"
  ]
}

Tech Stack

• Backend: Go (net/http)
• AI: Any OpenAI-compatible API (OpenAI, Groq, Together, Ollama, etc.)
• Frontend: HTML, Tailwind CSS (CDN), vanilla JavaScript
• Deploy: Docker, GitHub Actions

License

MIT