Drex 1.5 is an open 9B model that scores decision options instead of writing prose, ranked #1 under 10B params on the public Decision Index.
Yes, Drex 1.5 is open source under the Apache-2.0 (code) license.
Drex 1.5 is free to use.
Yes, Drex 1.5 can be self-hosted (the source is available under the Apache-2.0 (code) license).
Open-weight 9B decision model from Nace.AI that takes a state and a typed question (yes/no, multiple choice, or rating scale) and returns a probability for each option, without generating any text. Positioned for agent routing, classification, and policy checks over long documents where a fast scored answer beats a generated paragraph.
Most agent pipelines route every decision, even a simple yes/no gate, through a frontier chat model, paying chat-model prices and latency for a task that is really a scored classification. Drex's bet is a small, purpose-built model that only scores options and runs locally at a fraction of the cost and latency. The honest read: this is a brand-new repo (11 stars) from a young project, the benchmark claim is vendor-reported rather than independently reproduced, and the code license (Apache-2.0) does not automatically extend to the model weights, which carry separate, more restrictive terms — worth a narrow pilot on a low-stakes routing decision before trusting it on anything that touches production traffic or commercial use.