Cline

Pros

• +Fully open-source with transparent operation
• +Bring your own API key with any supported model provider
• +Human-in-the-loop approval keeps you in control
• +Runs inside VS Code so you stay in your editor
• +Active community with frequent updates

Cons

• −API costs can add up quickly on complex tasks
• −Slower than Claude Code due to the approval workflow for each action
• −Requires manual API key setup and configuration
• −Performance depends heavily on which model you choose

Cline is an open-source AI coding agent that runs as a VS Code extension. It brings agentic capabilities, reading files, writing code, running terminal commands, directly into your editor. What sets Cline apart is its human-in-the-loop design: every file change and command execution requires your explicit approval before it happens.

Because it is open-source and model-agnostic, you bring your own API key from any supported provider: Anthropic, OpenAI, Google, or even local models via Ollama. This gives you full control over costs and model selection.

Cline follows the agentic pattern of plan, act, and observe. It reads your project files to understand the codebase, proposes changes as visual diffs you can review, and executes terminal commands with your approval. The approval workflow makes it safer than fully autonomous agents but slower for large tasks.

It also supports MCP (Model Context Protocol) for connecting to external tools and data sources. Browser automation lets it open web applications and verify visual results, which is useful for front-end development.

Cline is a strong choice for developers who want agentic AI capabilities but prefer to stay inside VS Code. Its open-source nature makes it appealing for developers who value transparency and want to understand exactly what the tool is doing. The bring-your-own-key model also works well for developers who want to control costs or use specific models.

Cline's API costs depend on the model you choose and task complexity. A typical coding session with Claude can cost $1-5 in API credits. Track your usage carefully, especially when working on large codebases.