# Nace AI open-sources Drex 1.5 decision model

> Nace.AI released Drex 1.5, a 9‑billion‑parameter model that returns probabilities for each option in one pass and handles up to 128 K tokens.

Oossa · 2026-10-10 · https://oossa.com/en/nace-ai-open-sources-drex-1-5-decision-model

Nace.AI has open‑sourced Drex 1.5. The model has 9 billion parameters and scores each possible answer in a single forward pass. It can read up to 128 K tokens and achieved a 58.08 score on Decision Index 0.3.1. The code is now publicly available for anyone to download and run.

## The facts

- 9 billion‑parameter Drex 1.5 decision model
- Scores 58.08 on Decision Index 0.3.1; reads up to 128 K tokens

## Why it matters

Developers can build apps that pick the best option directly, cutting the steps needed for text‑based prompting.

## Sources & references

1. [Nace AI Open-Sources Drex 1.5: A 9B Decision Model That Scores Options, Not Text](https://www.marktechpost.com/2026/10/09/nace-ai-open-sources-drex-1-5-a-9b-decision-model-that-scores-options-not-text/) – MarkTechPost, 2026-10-10

Last updated: 2026-10-10