Cline

Open-source AI programming agent, officially said to adopt the Plan-then-Act mode to modify code across files and execute bash commands in editors and terminals, supporting MCP extensions and multi-Agent collaboration.

AI Developer Tools#AI Coding#Open Source#AI Agent

Updated: 2026-10-26

What is Cline?

Cline is an open-source AI programming agent, and its official website refers to itself as "The Open Coding Agent". Its core proposition is an open agent runtime: the official description is "an open-source agent runtime for your editor, terminal, or embedded into your own product". The quantitative data provided on the official website includes over 11 million developers, over 11 million cross-platform installations, 69.2k stars, as well as more than 250 contributors and the Apache 2.0 open-source license.

Who is it for?

Developers who work in an editor and want the agent to modify code as they write: First align with Plan mode before executing.
Teams maintaining large codebases: Use cross-file editing and checkpoints to control the scope of changes.
Engineering efficiency teams that need to integrate AI coding into CI: Use the CLI to run checks and updates in pipelines and scheduled tasks.
Teams with requirements on model sources or data boundaries: Connect to self-built endpoints or local models to have full control over models and infrastructure.
Teams looking to integrate agent capabilities into their own products: The official website lists dedicated SDK and Embed paths for this purpose.

Key features

Cross-file Editing

Officially described as coordinated multi-file modifications across the entire project, with linter-aware fixes, diffs, and checkpoints, supporting one-click undo.

Execute bash commands

Execute commands in the terminal and respond to the output in real time. The official statement says that long-running development servers, tests, and deployments can all be processed in real time.

Plan then Act

The official has made "planning first then execution" a mode switch — Plan mode aligns with strategies, and Act mode executes; you can review and approve each step one by one, or enable auto-approve to let it run automatically.

Rules and Skills

You can distribute .clinerules files alongside your repository to hand over your team's coding standards, architecture, and deployment conventions to the agent.

Choose your model and endpoint

Officially supports Claude, GPT, Gemini, local Ollama/LM Studio, or any OpenAI-compatible endpoint – "Bring your own key or your own weights".

Expansion and Collaboration

You can register custom tools and lifecycle hooks to connect to databases, APIs, and infrastructure via MCP servers; the coordinator agent can assign tasks to expert agents and run periodic tasks according to cron schedules; it can also drive operations in Slack, Linear, or CI pipelines.

How to use Cline

After installing it, first run a small requirement in Plan mode, check which files it intends to modify, and then switch to Act mode.
Make good use of checkpoints and one-click undo during the modification process: Confirm the diff before proceeding, which is more convenient than rolling back afterward.
Embed the team's conventions in the .clinerules file and distribute it with the repository, which is more stable than repeating the explanation every time.
Auto-approve can speed up the process but grants expanded execution permissions.
It is recommended to enable it only in trusted repositories and controlled environments, and to remain vigilant about the scope of command execution.
When connecting to an MCP server, it is recommended to prioritize choosing from the official MCP Marketplace: third-party tools mean delegating permissions to external services, so confirm what they can access before connecting.