Windsurf’s Foundational AI Models: SWE-1 and Beyond

In our last lesson, we transformed our relationship with the AI, moving from passive user to active director by shaping its behavior with custom rules. Now we turn our attention to the engines that power this intelligence.

Understanding the different AI models available in Windsurf is like a skilled mechanic knowing the difference between a high-torque diesel engine and a high-revving racing engine. Each model is a marvel of engineering, but each is built for a distinct purpose. To truly master Windsurf, a user must learn which engine best suits each task.

This lesson serves as a guide to the AI powerhouses at your command.

The SWE-1 model family

While Windsurf offers access to many popular commercial AI models, its soul lies in its own proprietary model family: SWE-1 (Software Engineering 1). Why invest in building models from scratch when so many others are available?

The answer lies in the Windsurf philosophy: to achieve true “flow state,” a developer needs an AI trained specifically on the unique, complex, and dynamic patterns of the software development life cycle. The SWE-1 models are specialists, trained from the ground up on a massive corpus of code and, crucially, on the patterns and dynamics of the software development process itself. They are built to think like engineers.

Let’s meet the family:

• SWE-1: This is the high-reasoning powerhouse, the architect and the project manager of the family. It is designed for deep, multi-step thinking. When you ask Cascade to perform a complex task like “refactor this class to use the repository pattern across three different files,” it’s the SWE-1 model that builds the plan, understands the dependencies, and directs the execution. It’s your go-to for tasks that require thought and planning.

• SWE-1-lite: This is the versatile workhorse. It strikes a crucial balance between high-level intelligence and speed. SWE-1-lite is perfect for the majority of your day-to-day interactions: explaining a block of code, generating a unit test, or answering a quick question about a library. It’s smart enough for nuanced tasks but fast enough that it feels responsive and conversational.

• SWE-1-mini: This is the speed specialist. Its entire architecture is optimized for one thing: near-instantaneous, low-latency code suggestions. This is the silent engine that powers Windsurf Tab’s autocomplete. It has to be fast enough to keep up with your typing without ever introducing a stutter or lag. While less powerful in its reasoning than its larger siblings, its specialized focus is what makes the core “typing flow” experience feel seamless and magical.

This tiered approach means Windsurf can apply the right level of computational power to each task, ensuring a smooth and efficient experience across the board.

Choosing the right tool for the job

With a full toolbox of models at your disposal, the critical skill becomes knowing which one to pick. Selecting the right model for the job is the ...