Duck2api is a lightweight API proxy server built in Go that wraps free LLM endpoints from DuckDuckGO into an OpenAI-compatible chat completions interface. It supports multiple models including GPT-4o-mini, Claude-3-haiku, llama-3.3-70b, mixtral-8x7b, and o3-mini, exposing them via a unified /v1/chat/completions endpoint. The project includes a web UI and supports Docker deployment, TLS configuration, and proxy pool integration.