Cline

Cline (formerly Claude Dev) is an open-source autonomous coding agent extension for VS Code, JetBrains, Cursor, Windsurf, Zed, and Neovim. It operates in a step-by-step approval loop: the agent proposes each action (create file, run command, open browser) and the user approves before execution — making it transparent and safe compared to fully autonomous tools. With 59,000+ GitHub stars and 5 million installs, it is the most widely adopted open-source coding agent in the VS Code ecosystem.

Cline reached v3.81 in May 2026 and receives daily updates. It supports Model Context Protocol (MCP) natively, allowing custom tool integrations. The extension works with any LLM via bring-your-own-key: Anthropic Claude, OpenAI, Gemini, AWS Bedrock, OpenRouter, and local models. It can read and edit files across the full codebase, execute terminal commands, run tests, and use a browser for research or end-to-end testing.

Key capabilities include multi-file editing with full codebase context, browser use for research and UI testing, MCP tool support, and an approval-based workflow that keeps the developer in control at every step. Unlike forked editors like Cursor or Windsurf, Cline runs inside your existing editor without requiring a migration.

Pricing: Cline itself is completely free and open source. You pay only for the LLM API calls you make to your chosen provider. Running on local models via Ollama is free.

Limitations: The step-by-step approval workflow, while safe, can slow down complex multi-file tasks compared to fully autonomous tools. Quality depends entirely on the LLM you configure. The BYOK model means you manage API costs separately.

Best suited for developers who want a powerful autonomous coding agent inside their existing editor without switching to a new IDE, and who prefer transparent step-by-step control over fully autonomous execution.