StartLux has released the family of open decision-making models, StartLux-Decision v1.1. The StartLux 27B Instant model now ranks first in the Decision Index 0.3.2 on the Hugging Face platform. StartLux is a company currently in the Genora incubation program.
The Decision Index is a community-supported ranking and is not affiliated with TypeSafe. As of October 16, the 27B Instant model took the top position, achieving a full score of 69.12. It also led in each of the three components of the ranking: 72.88 on public benchmarks, 64.82 in private tests for the same skills, and 61.41 in private tasks from new domains.
The second place was held by the vLLM-SR d3 model with a score of 66.26, and Jev 1.14 achieved a result of 61.53.
These models are designed to perform a narrow practical task. Given a state that can be represented as text, JSON, or images, along with a set of specified questions indicating types, the model outputs a probability for each option: selection from a list, a 'yes' or 'no' judgment, or a level on a scale. Instant models perform one direct pass using bidirectional attention over the query.
AutoThink models work similarly when confident in the answer; however, if the highest probability falls below a set threshold, which defaults to 0.6, they generate a brief chain of reasoning before re-analyzing the answer.
The lineup includes eight open models with parameters ranging from 0.8B to 27B in Instant and AutoThink variants, available in quantized GGUF and MLX formats. They can run on vLLM and MLX. The weights of these models are released under the CC BY-NC 4.0 license, which prohibits commercial use.
On the public subset of Decision Index 0.3, StartLux reports an independently obtained result of 73.37 for the 27B AutoThink model at a threshold of 0.9. Furthermore, the company introduced DecisionPivot—its own benchmark for verifiable decisions, created based on pairs of contrasts that differ by one detail changing the answer, covering policies, registries, graphs, permissions, and tool calls. StartLux claims an accuracy level of 86.9% for the 27B AutoThink model. It should be noted that both these metrics are data provided by the company itself, not independent results.
A technical report published on arXiv under number 2610.17309 describes a three-stage training process and a reinforcement learning method called RLCD-squared. This method rewards more accurately calibrated decision probabilities using correct scoring rules and softly penalizes excessively long reasoning. The authors claim this allowed them to reduce the average length of reasoning by approximately 65% while maintaining high accuracy.
Demonstrations on the project website show how the models perform step-by-step calls in chess, Super Mario Bros., StarCraft II, and in a computer-based shopping task, with a single text prompt given at each step.


