Cline Review 2026: The Top Open-Source Coding Agent?

What Is Cline?

Cline is the most-adopted open-source AI coding extension for VS Code, with over 5 million installs and 62,198 GitHub stars. Its core pitch: bring your own model (BYOM) and pay provider rates directly — no markup, no subscription lock-in. You connect your own API key for models like OpenAI or Anthropic, and Cline acts as a transparent agent that plans, edits, and runs terminal commands in your editor.

Real Cost: You Pay Provider Rates

Cline itself is free. Your only cost is the AI model usage. For example, using anthropic/claude-opus-4.1 at $15/M input and $75/M output, a typical coding session with 500K input tokens and 50K output tokens costs roughly $11.25. With openai/o3-pro ($20/M in, $80/M out), the same session would be about $14. There is no Cline markup — you pay exactly what the provider charges.

Plan/Act Modes, MCP Support, and Multi-File Edits

Cline operates in two modes: Plan (analyzes and proposes changes) and Act (executes edits and commands). It supports the Model Context Protocol (MCP), allowing it to interact with external tools like databases or APIs. Multi-file edits are handled in a single request — Cline can modify several files at once, which is a major productivity boost for refactoring tasks.

Where Cline Beats Managed IDEs

Unlike managed IDEs (e.g., Cursor, GitHub Copilot), Cline gives you full control over the model and cost. You can switch between openai/gpt-5.5-pro ($30/M in, $180/M out) for complex reasoning and openai/gpt-4 ($30/M in, $60/M out) for cheaper tasks. There is no vendor lock-in, and you can use the latest models as soon as they are available.

Where Cline Asks More of You

Cline requires you to manage API keys and monitor token usage. There is no built-in rate limiting or cost cap — you must set your own limits. The setup is more technical than a managed IDE, and you need to understand model pricing to avoid surprises. Additionally, Cline does not offer a hosted backend; all processing happens via your API calls.

GitHub Stars, 5M Installs, Contributor Health

With 62,198 stars on GitHub and over 5 million VS Code installs, Cline has a large and active community. The repository sees frequent commits and releases, with a healthy contributor base. However, as an open-source project, support is community-driven — there is no official customer support team.

Verdict: Who Should Run Cline

Developers who want full control over their AI coding costs and model choices will love Cline. It is ideal for power users comfortable with API keys and token management. If you prefer a plug-and-play experience with built-in cost controls, a managed IDE might be simpler. But for transparency and flexibility, Cline is unmatched.