Cline

What is Cline?

Cline (formerly Claude Dev) is an open-source autonomous AI assistant and agent designed as an extension for Microsoft VS Code. Unlike basic autocomplete copilots, Cline is capable of managing complete, end-to-end development tasks. It can read your project's structure, analyze errors, create new files, modify existing files (either contextually or across multiple directories), run terminal commands in an integrated manner, and use web browser tools to test the outputs.

How it works

Cline works by integrating directly into VS Code via the side panel. The user provides their own API keys (such as OpenAI, Anthropic/Claude, Gemini, DeepSeek, or local providers like Ollama). Upon receiving a natural language instruction (e.g., "Create a modern login screen in React and add form validation"), Cline builds a step-by-step strategy. It reads the necessary project files, proposes precise code edits, asks the user for approval to run build/test commands in the terminal, and checks if the compiler reported lints or errors, correcting them autonomously.

Key Features

• Non-Destructive File Modification: Proposes changes in specific code blocks, displaying a visual diff comparison before applying them.
• Integrated Terminal Execution: Runs scripts, installs npm/pip packages, and executes automated tests directly with user permission.
• Integrated Web Browser: Opens invisible or visible browsers to debug visual layouts and read front-end console logs.
• Multi-Provider LLM Support: Compatible with API keys from Anthropic, Google Gemini, OpenAI, DeepSeek, OpenRouter, and local models via Ollama/LM Studio.
• Task History and Resuming: Allows pausing complex programming tasks and resuming them at any time.

Available Integrations

Cline operates at the core of the developer's environment:

• Native extension for Microsoft VS Code / Cursor Editor.
• Connectivity to dozens of API providers such as Anthropic, OpenAI, DeepSeek, Google AI Studio, and OpenRouter.

Who is it for?

• Software Developers (Full-stack, Front-end, and Back-end) looking to speed up repetitive boilerplate tasks or complex refactorings.
• Beginner Programmers seeking tutoring and immediate hands-on help writing structured code within their projects.
• Product and Engineering Teams looking for agile tools for rapid feature prototyping.

Pricing

Pros and Cons

Pros:

• Extraordinary autonomy to locate and fix bugs in large repositories.
• Allows using very cheap API keys (like Gemini Flash or DeepSeek) or running local models with no extra costs.
• Complete developer control, enabling approval or rejection of each change before it is applied.

Cons:

• Can consume a significant amount of context tokens on long-running tasks, increasing the API key bill if not monitored.
• Depends on strong models (like Claude 3.5 Sonnet) for highly complex tasks and architectural decision-making.

Alternatives to Cline

If you are looking for other AI coding tools, consider Cursor Editor, GitHub Copilot Workspace, Aider (via command line), and Devin (by Cognition).