Cline

Cline is an open-source AI coding agent that runs inside VS Code, your terminal, CI pipelines, or your own product through its SDK. It is built for developers who want an autonomous agent that edits across a whole project, runs commands, and works with any model while you keep control of cost.

Key Highlights

• Coordinated multi-file edits with diffs, checkpoints, and one-click undo on every step
• Plan mode to agree a strategy first, then Act mode to execute with step approval or auto-approve
• Runs bash commands in your terminal and reacts to output live, including servers and tests
• Works with Claude, GPT, Gemini, local Ollama or LM Studio, and any OpenAI-compatible endpoint
• Extends through MCP servers and an SDK, plus Slack, Discord, Linear, and CI integrations
• Apache 2.0 licensed across the VS Code extension, CLI, SDK, and embeddable runtime

What Makes It Different

Cline is genuinely open source (Apache 2.0) and model-agnostic, so it never sells you inference at a markup. Its Plan-and-Act split is the core mechanism: Plan mode lists which files it will touch and the steps it will take, then Act mode carries them out one approval at a time, keeping the agent transparent and reviewable rather than a black box.

Features & Capabilities

You point Cline at a task and it reads the codebase, proposes a plan, then makes coordinated changes across many files while keeping imports, types, and behavior consistent. It runs tests, starts dev servers, and reacts to terminal output live. A .clinerules file teaches it your standards, architecture, and deployment conventions.

Beyond the editor, the CLI runs in scripts, cron jobs, and CI pipelines. You can register custom tools and MCP servers and set up multi-agent teams where a coordinator delegates to specialists. Cline is built by 250+ contributors and backed by a $32M seed and Series A round.

User Ratings and Testimonials

Cline is widely rated as one of the strongest open-source coding agents and is installed by more than 8 million developers. Reviewers praise the transparent Plan/Act workflow, the lack of vendor lock-in, and support for many providers, including local models. The common criticism is that it suits power users more than beginners, and that bring-your-own-key inference costs can add up on large tasks.

Pricing & Value

• Open Source: Free for individual developers. Includes the VS Code extension, CLI, MCP marketplace, and multi-root workspaces. You pay only for AI inference with your own API keys or Cline's at-cost provider; no subscription or seat fees.
• Enterprise: Custom pricing. Adds the JetBrains extension, SSO, role-based access control, centralized billing, a team dashboard, audit logs, and an SLA.

Because the tool is free and you pay model providers directly, Cline is one of the cheapest ways to run an autonomous coding agent, especially for developers who already hold API keys.