Laguna XS 2.1 is a 33B total parameter Mixture-of-Experts model with 3B activated parameters per token designed for agentic coding and long-horizon work on a local machine.

Applications

Claude Code ollama launch claude --model laguna-xs-2.1

OpenCode ollama launch opencode --model laguna-xs-2.1

Hermes Agent ollama launch hermes --model laguna-xs-2.1

OpenClaw ollama launch openclaw --model laguna-xs-2.1

We are currently investigating an issue using Laguna XS 2.1 on macOS. This will be updated once the issue is resolved.

Laguna XS 2.1

Laguna XS 2.1 is a 33B total parameter Mixture-of-Experts model with 3B activated parameters per token designed for agentic coding and long-horizon work on a local machine. This model is an upgraded version of our Laguna XS.2 model with a +5.4% jump on SWE-bench Multilingual as well as stronger performance on terminal-style tasks.

For more details on how we train, including on data automixing and async off-policy agent RL, check out our recent technical report.

Highlights

Mixed SWA and global attention layout: Laguna XS 2.1 uses sigmoid gating with per-layer rotary scales, enabling mixed SWA (Sliding Window Attention) and global attention layers in a 3:1 ratio (across 40 total layers)
KV cache in FP8: KV cache quantized to FP8, reducing memory per token
Native reasoning support: Interleaved thinking between tool calls with support for enabling and disabling thinking per-request
Local-ready: At 33B total parameters and 3B activated, Laguna XS 2.1 is compact enough to run on a Mac with 36 GB of RAM. Available on Ollama and llama.cpp. High-quality FP8, NVFP4 and INT4 quantized variants available (see the collection)
OpenMDW-1.1 license: Use and modify the model and associated materials freely for commercial and non-commercial purposes (learn more about OpenMDW)

Model overview

Training: pre-training, post-training and reinforcement learning stages
Number of parameters: 33B total with 3B activated per token
Optimizer: Muon
Layers: 40 layers (10 layers with global attention, 30 layers with sliding window attention)
Experts: 256 experts with 1 shared expert
Sliding Window: 512 tokens
Modality: text-to-text
Context window: 262,144 tokens
Reasoning support: interleaved thinking with preserved thinking

Benchmark results

Model	Size (total params.)	SWE-bench Verified	SWE-bench Multilingual	SWE-Bench Pro (Public Dataset)	Terminal-Bench 2.0
Laguna XS 2.1	33B	70.9%	63.1%	47.6%	37.5%
Laguna XS.2	33B	69.9%	57.7%	46.3%	35.7%
Qwen3.6-35B-A3B	35B	73.4%	67.2%	49.5%	51.5%
North Mini Code	30B	67.6%	-	40.2%	36.0%
MAI-Code-1-Flash	137B	71.6%	65.5%	51.2%	54.8%
gpt-oss-120B	120B	-	-	16.2%	18.7%
Claude Haiku 4.5	-	73.3%	-	39.5%	29.8%
GPT-5.4 Nano	-	-	-	52.4%	46.3%

We used the highest publicly-referenced scores for all comparison models across each benchmark. In all cases these were official scores published in release blog posts or equivalent, with the exception of gpt-oss-120b and Claude Haiku 4.5 where the highest published (verified) scores for SWE-Bench Pro and Terminal-Bench 2.0 are from their respective official leaderboards.

Expand for benchmarking methodology

All benchmarking for Laguna XS 2.1 was completed using Laude Institute’s Harbor Framework with our [agent harness](https://github.com/poolsideai/pool), with a maximum of 500 steps and sandboxed execution. The same sampling parameters were used for all Laguna XS 2.1 benchmarking: temperature=1.0, top_k=20 and top_p=1, with thinking mode enabled and a context length of 256K tokens. All tasks were run in their own sandbox using 8 GB RAM/2 CPUs, with the exception of Terminal-Bench 2.0, which used 48 GB RAM/32 CPUs. Some base task images and verifiers were patched to fix infrastructure reliability issues inherent in task setup, such as rate limits on third-party dependencies in external registries used by the verifier. All four agentic benchmarks were run with patched images. We also ran a reward-hack judge post-hoc on Laguna XS 2.1 evaluation runs and did not find significant reward hacking after joint judge review and manual review. - SWE-bench Verified: mean pass@1 averaged over 4 attempts per task - SWE-bench Multilingual: mean pass@1 averaged over 4 attempts per task - SWE-Bench Pro: mean pass@1 averaged over 2 attempts per task - Terminal-Bench 2.0: mean pass@1 averaged over 5 attempts per task; 48 GB RAM/32 CPUs

Usage

Laguna XS 2.1 has launch-day support in vLLM, SGLang, Transformers and Llama.cpp, and TRT-LLM thanks to the support of the team at NVIDIA.

The fastest way to get started is using OpenRouter.

We are providing free inference for a limited time for Laguna XS 2.1, as well as our larger 225B model, Laguna M.1. Visit our provider page on OpenRouter to get started.

pool

pool is a lightweight terminal-based coding agent and a dual Agent Client Protocol client-server.

Download and install for macOS and Linux:

curl -fsSL https://downloads.poolside.ai/pool/install.sh | bash

Use pool with Ollama with one-command setup:

ollama pull laguna-xs-2.1
ollama launch pool --model laguna-xs-2.1

Feedback and issues

Submit feedback with /feedback and read the full documentation on GitHub.

Local deployment

Laguna XS 2.1 is supported in vLLM, SGLang, Transformers and Llama.cpp, and TRT-LLM thanks to the support of the team at NVIDIA. Use Laguna-XS 2.1 with Ollama (with MLX support) and the mlx-lm framework for the best experience on your local machine.

Ollama

Available on the Ollama library.

ollama run laguna-xs-2.1          # default — Q4_K_M (imatrix)
ollama run laguna-xs-2.1:q8_0     # higher precision
ollama run laguna-xs-2.1:bf16     # full precision

Reasoning and tool-calling work out of the box via the built-in laguna template.

macOS (Metal) users: Chat (ollama run / /api/chat) works as expected on Linux/CUDA. On macOS/Metal it may currently return empty output; the root cause is not yet fully understood and we’re investigating it with the Ollama team. On a Mac, use a Linux/CUDA host, or the /api/generate endpoint with "raw": true.

Controlling reasoning

Laguna XS 2.1 has native reasoning support and is designed to work best with preserved thinking, where reasoning content from prior assistant messages is preserved in the message history. This model will generally reason before calling tools and between tool calls.

Reasoning may not be generated in follow-up steps if prior thinking blocks are dropped (i.e., thinking is not preserved) when messages are reconstructed over multiple steps.

Expand for example

```python import json from openai import OpenAI client = OpenAI( base_url="https://openrouter.ai/api/v1", api_key="...", ) model = "poolside/laguna-xs-2.1" tools = [{"type": "function", "function": { "name": "shell", "description": "Execute a bash command and return the output.", "parameters": {"type": "object", "properties": {"cmd": {"type": "string"}}, "required": ["cmd"]}, }}] messages = [ {"role": "system", "content": "You are a coding agent with access to a shell tool."}, {"role": "user", "content": "Run uname -a"}, ] # Thinking is enabled by default when the server sets --default-chat-template-kwargs {"enable_thinking": True} # When using OpenRouter's Chat API (https://openrouter.ai/api/v1), this flag is set by default response = client.chat.completions.create( model=model, messages=messages, tools=tools, stream=True, ) reasoning, content, tool_calls = "", "", [] for chunk in response: delta = chunk.choices[0].delta if hasattr(delta, "reasoning_content") and delta.reasoning_content: reasoning += delta.reasoning_content if hasattr(delta, "content") and delta.content: content += delta.content if hasattr(delta, "tool_calls") and delta.tool_calls: for tc in delta.tool_calls: if tc.index >= len(tool_calls): tool_calls.append({"id": tc.id, "function": {"name": "", "arguments": ""}}) if tc.function.name: tool_calls[tc.index]["function"]["name"] = tc.function.name if tc.function.arguments: tool_calls[tc.index]["function"]["arguments"] += tc.function.arguments print(f"Reasoning: {reasoning}\nContent: {content}\nTool calls: {tool_calls}\n") # Return reasoning in the next request for best performance messages.append({ "role": "assistant", "content": content, "reasoning_content": reasoning, "tool_calls": [{"id": tc["id"], "type": "function", "function": tc["function"]} for tc in tool_calls] }) messages.append({ "role": "tool", "tool_call_id": tool_calls[0]["id"], "content": json.dumps({"stdout": "Darwin arm64", "exit_code": "0"}) }) response = client.chat.completions.create( model=model, messages=messages, tools=tools, stream=True, ) reasoning, content = "", "" for chunk in response: delta = chunk.choices[0].delta if hasattr(delta, "reasoning_content") and delta.reasoning_content: reasoning += delta.reasoning_content if hasattr(delta, "content") and delta.content: content += delta.content print(f"Reasoning: {reasoning}\nContent: {content}") ```

Disabling reasoning

You can disable thinking by setting enable_thinking to False in a request or by not providing --default-chat-template-kwargs {"enable_thinking": True} or equivalent when starting the server.

Expand for example

```python from openai import OpenAI client = OpenAI() completion = client.chat.completions.create( model="poolside/laguna-xs-2.1", messages=[ {"role": "user", "content": "Write a retry wrapper with exponential backoff."} ], extra_body={ "chat_template_kwargs": { "enable_thinking": False }, }, stream=True ) for chunk in completion: print(chunk.choices[0].delta) ```

For agentic coding use cases, we recommend enabling thinking and preserving reasoning in message history as outlined in the Controlling reasoning section.

License

This model is licensed under the OpenMDW-1.1 License.

Intended and Responsible Use

Laguna XS 2.1 is designed for software engineering and agentic coding use cases, and you are responsible for confirming that it is appropriate for your intended application. Laguna XS 2.1 is subject to the OpenMDW-1.1 License, and should be used consistently with Poolside’s Acceptable Use Policy. We advise against circumventing Laguna XS 2.1 safety guardrails without implementing substantially equivalent mitigations appropriate for your use case.

Please report security vulnerabilities or safety concerns to [email protected].