Cline

Cline is an open-source AI coding agent that lives inside your existing VS Code as a standard extension — no forked IDE, no migration, no losing your keybindings and plugins. You bring your own API key for whichever LLM you prefer (Claude, GPT-4o, Gemini, DeepSeek, or a local model), and Cline handles the agentic loop: reading your codebase, planning changes, writing diffs, and waiting for your approval before touching anything. The two-phase Plan/Act model means you can discuss an approach with the agent before it starts modifying files. When it does act, every change surfaces as a reviewable diff — nothing lands in your codebase silently. This keeps you in control without making the tool feel like a rubber stamp. Pricing is straightforward: Cline itself costs nothing. You pay only what your chosen LLM provider charges per token, with no Cline markup or subscription on top. For developers already paying for Claude or OpenAI API access, this often works out significantly cheaper than Cursor or Windsurf subscriptions, especially at lower usage volumes.

• Installs as a standard VS Code extension — your existing settings, themes, and plugins are untouched.
• Plan mode lets you review and refine the agent's approach before any file is modified.
• Every code change is shown as a diff you must approve — no silent edits.
• Plug in any supported LLM: Claude, GPT, Gemini, DeepSeek, or a local model via compatible API.
• Pay LLM providers directly at their published rates — no Cline markup or subscription fee.
• Apache 2.0 licensed — audit the source, fork it, or contribute upstream.
• Handles multi-file edits and terminal commands as part of the agentic loop.
• Works with local models, keeping code entirely on your own infrastructure if needed.