Laguna XS.2

Laguna XS.2 is the first public open-weight model from Poolside AI, a company that has been quietly building coding-specific foundation models since 2023. Released on April 28, 2026, it uses a Mixture-of-Experts (MoE) architecture — 33 billion total parameters but only 3 billion active at inference time. That efficiency means you can run it locally on a single GPU with 36GB VRAM or even a MacBook Pro with 36GB unified memory, which is remarkable for a model at this benchmark level.

The headline number is 68.2% on SWE-bench Verified, which places Laguna XS.2 in the same ballpark as models several times its size. Poolside achieved this by training exclusively on code-related data — not general web text — and designing the architecture specifically for agentic workflows where the model needs to plan, edit files, run tests, and iterate across multi-step coding tasks. This isn't a general-purpose LLM that happens to code; it's a coding model through and through.

The weights are released under Apache 2.0 with no usage restrictions, and there's free API access through both Poolside's own endpoint and OpenRouter during a limited preview period. For teams that want to self-host a coding model without per-token API costs — or developers who want local inference for privacy reasons — Laguna XS.2 is immediately one of the strongest options available. The main caveat: it's narrowly focused on code, so don't expect strong performance on general knowledge or non-programming tasks.