Models & Research

Nace AI Open-Sources Drex 1.5: A 9B Decision Model That Scores Options, Not Text

· October 10, 2026
Nace AI Open-Sources Drex 1.5: A 9B Decision Model That Scores Options, Not Text

What happened

Nace.AI open-sourced Drex 1.5, a 9 billion parameter decision model that evaluates choices by scoring options instead of just analyzing text. Its core capability is returning a probability distribution across all options in one forward pass. The model supports very long input sequences, reading up to 128,000 tokens. Drex 1.5 scores 58.08 on the Decision Index 0.3.1 benchmark, indicating strong performance in decision-making tasks.

Why it matters

Drex 1.5’s architecture challenges the typical approach of text-centric large language models by focusing on decision scoring. This shift can simplify tasks where selecting the best option is key, such as recommendation systems, multi-choice problem solving, or structured decision analysis. The ability to handle up to 128K tokens in one pass enables complex scenarios involving large context windows, which are increasingly common in enterprise and AI-powered automation workflows.

Open-sourcing a 9B parameter decision model lowers barriers for builders who want to integrate decisive AI components without training massive models from scratch. It pressures incumbents to either match this decision-driven approach or improve their handling of choice-based tasks. The Decision Index score provides a concrete measure for comparing decision-focused models going forward, which benefits operators aiming to benchmark alternatives for production.

What to watch next

Follow how the ecosystem adopts Drex 1.5’s approach in real-world applications, especially in decision-heavy environments like finance, healthcare, and complex query answering. Check for third-party extensions or tools built on the model that facilitate integration into automated workflows or decision support systems. Watch if other AI developers recalibrate their model architectures to support option scoring instead of solely language generation. Model updates, ecosystem tooling, and performance against evolving benchmarks will reveal whether decision models like Drex shift AI development priorities toward actionable outputs.

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