Cline
Cline is an open-source autonomous coding agent that lives inside VS Code. Give it a task and it plans the work, edits files, runs commands and checks the results on its own, with every step visible and under your control.
Quick Facts
| Developer | Cline (open source; created by Saoud Rizwan) |
|---|---|
| First released | 2024 (as Claude Dev) |
| Latest version | See official website |
| Platform | VS Code |
| License | Apache 2.0 |
| Pricing | Free and open source; bring your own API key |
What is Cline?
Cline is an autonomous coding agent that runs as a VS Code extension. It started life under the name Claude Dev, and it became famous for doing real work: you describe a task, and the agent reads your project, plans the steps, writes code, runs terminal commands and even opens browsers to verify results.
The agent works with your own API keys for models like Claude, GPT and many others, which means there is no mandatory subscription to the tool itself. Every action Cline takes is shown to you, and you can approve or reject each step, so it feels like supervising a capable junior developer.
Cline's popularity helped define the open-source autonomous agent category in code editors, and its approach inspired a whole family of forks and similar tools.
Key Features
- Autonomous planning and execution of multi-step coding tasks
- Reads and edits files across your whole project
- Runs terminal commands to build, test and verify
- Permission system so you approve every action
- Works with many model providers via your own API keys
- Plan mode for thinking through changes before acting
- Checkpoint and diff review for each modification
- MCP (Model Context Protocol) support for extra tools
How to get started
Install Cline from the VS Code marketplace, then add your API key in the extension settings. Open a project, describe a task, and watch the agent work through it step by step, approving actions as it goes.
- Install the Cline extension from the VS Code marketplace
- Add your API key for your preferred model provider
- Open your project in VS Code
- Describe a task in the Cline chat panel
- Approve the steps it proposes and review the final diff
Use cases
- Implementing a feature across multiple files
- Fixing bugs by having the agent reproduce and patch them
- Writing and running tests automatically
- Refactoring legacy code with human oversight
- Scaffolding new projects and boilerplate
- Exploring and documenting unfamiliar codebases
Pricing and licensing
Cline is free and open source under the Apache 2.0 license. There is no required subscription: you connect your own model API keys, and you pay whatever your model provider charges for usage.
The open-source project is backed by a company that also offers enterprise options and hosted services, so teams can get support and managed infrastructure if they want it. Check the official website for the latest offerings.
Pros and cons
Cline's superpower is true autonomy with transparency. It can complete multi-step tasks end to end, yet every action is visible and reversible, which builds trust. Model freedom and the Apache 2.0 license are also big draws.
The flip side is that autonomous agents can be slow, spend tokens on failed attempts, and occasionally need close supervision on complex tasks. Running it well also assumes you are comfortable managing API keys and model costs.
Alternatives
- Roo Code: open-source fork of Cline with more customization
- Kilo Code: AI coding agent for VS Code and JetBrains
- Continue: open-source AI assistant for VS Code and JetBrains
- Aider: AI pair programming in the terminal
- OpenCode: open-source terminal AI coding agent