Building an Agent with the Cline SDK
In this article, we will build a small release notes generator that uses the Cline SDK to inspect recent git history and turn it into readable markdown.
Cline is an open-source AI coding agent focused on real software work. Most developers first encounter Cline as an assistant in the editor or terminal, but Cline is broader than a single interface.
It has both a CLI and an SDK:
The CLI is for running agent workflows directly from the terminal
The SDK is for embedding the same agent runtime inside your own scripts, products, CI jobs, and internal tools
That distinction matters. In the Cline SDK launch post, the team explains that the original product started inside the VS Code extension, and over time the runtime became harder to separate from the IDE around it. The SDK is the answer to that problem: the agent runtime is treated as a shared service rather than an implementation detail hidden inside one app.
That is also why the SDK is more interesting than a thin API wrapper, the same runtime now powers Cline across the CLI and IDE surfaces, while staying open for other teams to embed in their own products. The low-level agent loop stays reusable, and the stateful runtime around it becomes more durable, portable, and product-agnostic.
