Most AI coding tools sit at two extremes: an autocomplete that only suggests, or a fully autonomous agent that runs off and does things you can't see. Cline lives in the useful middle. It's an open-source VS Code extension that acts as an agent - it can read your project, edit multiple files, and run terminal commands - but it asks for your approval at each consequential step, showing you the diff or the command before it happens. It's the human-in-the-loop version of an AI pair programmer.
Plan, Then Act - With Approval
Cline separates thinking from doing. In a planning phase it explores the codebase and proposes an approach; in the acting phase it makes changes one reviewable step at a time. Every file edit shows up as a diff you approve or reject, and every terminal command waits for your yes. You're never surprised by what it did, because nothing happens without a click.
It Uses Your Terminal and Browser
Beyond editing, Cline can run commands - install a dependency, run tests, start a dev server - and read the output back to decide what to do next. It can also drive a browser to check its own work on a running app. Each of these capabilities is gated behind the same approval step.
Model and MCP Flexibility
Cline is model-agnostic: point it at a hosted frontier model or a local one. It also supports the Model Context Protocol, so you can extend it with external tools and data sources - and it can even help you install new MCP servers on the fly.
Rough Edges and Limitations
- Approval fatigue is real. The safety of clicking through every step is also a cost on large tasks; you'll want a strong model to keep the number of steps down.
- It leans on capable models. Agentic multi-step work exposes weak models quickly; budget for a good one.
- Token usage adds up. Reading files and iterating consumes context; large repos mean larger prompts.
- Still evolving fast. The agentic-editor space moves quickly, and behavior changes between releases.
If you want an in-editor agent that does real work but never acts behind your back, Cline's approve-every-step model is the most reassuring way to let AI touch a codebase you care about.
Internal link suggestion: link "pausing for your approval" to the Aider post, which shares the same approval-first philosophy from the command line.
