Cline: an open-source coding agent that asks before it acts

Repo: cline/cline · Apache-2.0

Cline is one of the AI coding tools I've used for prototyping and automation projects. It's an open-source autonomous coding agent that runs as an IDE extension, a CLI or an SDK. What I like about it is less the autonomy than the brakes.

The features that matter

• Plan and Act modes. In Plan mode it explores the codebase and proposes a strategy. In Act mode it carries the plan out.
• Approvals by default. File edits and terminal commands need your sign-off unless you choose to auto-approve.
• MCP support. It can connect to Model Context Protocol servers for tools like databases, docs and issue trackers.
• Bring your own model. Anthropic, OpenAI, Google, local models through Ollama or LM Studio, or hundreds of models through OpenRouter.

How I work with coding agents

• Plan first, always. Reading the agent's plan before any edit catches most wrong turns in the cheapest possible place.
• Small, reviewable steps. One feature or fix per session. Big sessions produce big diffs nobody reviews properly.
• Tests as the referee. The agent can write tests, but passing tests I've read are what decide whether a change stays.
• Keep secrets out of reach. Don't give an agent credentials it doesn't need for the task in front of it.

The lesson from hardware

The same rule I use for AI-assisted PCB review applies to code: the AI proposes, something deterministic verifies. On a board that's the datasheet and the bench; in software it's the test suite and a human reading the diff.

SolveBlock's firmware is a good example. AI agents helped write and check a lot of it, and the most valuable artefact that came out of that work was a corrected milestone list where a checkmark only means "verified by something that was run". I wrote about it in Inside SolveBlock Core Rev C.

Who it suits

Cline suits people who want an agent that stays inside their editor and their rules. If you want full autonomy, there are tools that will happily take it — but the approval step is where most of the quality comes from.