# Drex 1.5

> Updated 2026-10-10 · type: tool · category: ai-infrastructure · status: active · rev 1

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.

- Open source: yes (Apache-2.0 (code))
- Self-hostable: yes
- Pricing model: free
- Best for: A team building agent routing, classification, or policy checks over long documents that needs a fast, scored answer rather than a generated paragraph, and wants to run it on owned hardware instead of paying per-call for a frontier LLM to do the same narrow job.
- Not for: Anyone needing the model to generate free-form text, summaries, or conversational output — Drex only scores structured options, it does not write prose.
- Last verified: 2026-10-10

- **Canonical:** https://gtmstacker.com/registry/tool/drex/
- **Source:** [github · nace-ai/drex-decision-models](https://github.com/nace-ai/drex-decision-models)
- **Tags:** ai-infrastructure, self-hostable, open-weights, agents, routing
- **Repository:** https://github.com/nace-ai/drex-decision-models

## Is Drex 1.5 open source?

Yes, Drex 1.5 is open source under the Apache-2.0 (code) license.

## How much does Drex 1.5 cost?

Drex 1.5 is free to use.

## Can I self-host Drex 1.5?

Yes, Drex 1.5 can be self-hosted (the source is available under the Apache-2.0 (code) license).


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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.

## Provenance

- Runtime/code Apache-2.0, 11 stars, 1 fork — independently WebFetch-verified 2026-10-10 (github.com/nace-ai/drex-decision-models). Model weights are under separate licenses (Open RAIL-M / CC BY-NC 4.0), not Apache-2.0.
- Surfaced via the 2026-10-10 OSS X pull, cross-referenced against MarkTechPost's 2026-10-09 coverage of the release.
- Curated from the GTM Stacker signal registry (2026-10-10 pass); license independently verified 2026-10-10.

## Why it matters for a GTM stack

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.