Cline is an open source, autonomous coding agent. Instead of just autocompleting the line you're typing, Cline can read your entire project, plan out a set of changes, edit multiple files, run terminal commands, and check its own work against linter and compiler errors, all with you reviewing and approving each step.
It started as a VS Code extension (previously known as "Claude Dev"), but it has grown into something bigger. Today, Cline ships as four things built on the same underlying engine:
@cline/sdk) for developers who want to build their own agents, custom tools, or integrations on top of Cline's engine.
It's licensed under Apache 2.0, and as of this writing has over 67,000 stars and more than 7,000 forks on GitHub, so it has real traction, not just a novelty project.
Here's a breakdown of the core capabilities, in plain terms.
Cline doesn't just look at the file you have open. It reads your project structure, figures out how files relate to each other, and makes coordinated edits across the codebase. While it works, it watches for linter and compiler errors and tries to fix problems like missing imports or type mismatches before you even notice them. Every edit shows up as a reviewable diff, and changes are tracked with checkpoints so you can undo the agent's work if something goes wrong.
Cline can execute commands directly: installing packages, running build scripts, executing tests, deploying, managing databases. For long-running processes like a dev server, it keeps watching the output in the background and reacts to new errors or crashes as they appear.
This is one of Cline's more distinctive features. In Plan mode, Cline explores your code, asks clarifying questions, and proposes a strategy before touching anything. Once you're happy with the plan, you switch to Act mode and it executes. By default, every file edit and command needs your approval — though you can flip on auto-approve if you want it to run more autonomously.
You can define project-specific rules in .clinerules files: coding standards, architecture conventions, deployment steps, testing requirements. These are picked up automatically across the CLI, VS Code extension, and JetBrains plugin, so the agent behaves consistently with your team's conventions rather than guessing.
This is a big differentiator. Cline doesn't force you onto a single provider. You can plug in:
You bring your own API key, and you decide what you're paying for and which model fits the task.
Using the SDK, you can register custom tools and lifecycle hooks for logging, auditing, policy enforcement, or domain-specific capabilities. Cline also supports MCP (Model Context Protocol) servers, so it can connect to databases, call APIs, manage cloud infrastructure, or use community-built tools. You can even ask Cline to write a new custom tool on the fly.
Newer additions let you coordinate multiple agents on a single task, with a coordinator agent delegating subtasks to specialists, and state persisting across sessions. You can also schedule agents to run on a cron schedule for recurring work like daily PR summaries or weekly dependency checks.
Cline can connect to messaging platforms so you can hand it tasks from Slack, Telegram, Discord, Google Chat, WhatsApp, or Linear, with each conversation thread mapped to a full agent session.
For automation, Cline can run with zero interaction: pipe input in, get JSON output back, and chain it into scripts or pipelines. For example:
cline "Run tests and fix any failures"
git diff origin/main | cline "Review these changes for issues"
For the CLI:
npm i -g cline
For the editor experience, install the VS Code extension or the JetBrains plugin, then connect your API key from whichever model provider you want to use.
Short answer: yes, especially if any of the following sound like you.
Try Cline if:
Think twice, or pair it with something else, if:
It's worth being clear-eyed about where Cline sits in the current landscape:
Neither of these makes Cline "better" or "worse" outright. It's a different set of trade-offs: openness and model flexibility versus the tighter polish of a closed, single-vendor product.
Repository: github.com/cline/cline