twinny

It provides inline code completion (filling code as you type), conversational code assistance in a side panel, code explanation, and test generation covering the core use cases of commercial AI coding tools within a privacy-preserving architecture.

The plugin connects to any OpenAI-compatible API endpoint, making it compatible with local model servers (Ollama, LM Studio, Jan), self-hosted deployments (vLLM, Xinference), and cloud APIs (OpenAI, Anthropic, Mistral).

Model selection, context window size, temperature, and other generation parameters are configurable per use case, allowing users to balance speed and quality using a fast local model for inline completion and a more capable API model for complex code analysis tasks.

Twinny is open-source under the MIT license and is the most fully-featured free alternative to GitHub Copilot and Cursor in the VS Code extension ecosystem.

It is used by developers who want Copilot-level functionality without the subscription cost, engineers in organizations with strict data policies that prohibit sending code to cloud AI services, and practitioners who want to experiment with different models for code generation without being locked into a single provider's quality and pricing.