Cline is an open-source VS Code extension that gives the editor a fully agentic coding loop. The developer describes a task in the Cline side panel; the agent reads and writes files, runs terminal commands, and controls a browser, all within the familiar VS Code environment. It supports any LLM provider via a configurable API backend and extends through MCP servers.
Key capabilities
IDE-native agentic loop — Unlike CLI tools that run outside the editor, Cline operates inside VS Code. It has access to the editor’s open files, workspace diagnostics (TypeScript errors, ESLint warnings), and terminal without context switching.
File system and terminal access — Cline can read, create, edit, and delete files across the workspace and run arbitrary shell commands. Each proposed action is shown to the developer for approval before execution.
Browser control — A built-in browser tool lets Cline navigate to the local dev server or any URL, screenshot the result, and iterate on UI changes in a single conversation turn.
Multi-provider LLM support — Cline routes requests to any compatible API: Anthropic, OpenAI, Google, Together AI, Ollama local models, and more. Model choice is per-task.
MCP support — Cline integrates with Model Context Protocol servers for database access, internal APIs, and custom tooling, using the same extension point as Claude Code and Gemini CLI.
Autonomy level
Level 3 (supervised agent): every file edit and terminal command is shown as a diff or command preview, and the developer approves or rejects before execution. A fully automatic mode exists for trusted workflows.
Strengths
- Stays inside VS Code — no terminal context switch required
- Open source (Apache 2.0) and model-agnostic
- Browser control inside the same IDE workflow is unique among VSCode extensions
- Active community with frequent releases
Limitations
- VS Code only; not available for JetBrains or other IDEs
- Quality and behavior vary significantly by model choice
- Each approval step can slow down high-frequency iteration