Nace.AI · DECISION MODEL

Drex v2.0

A 35B mixture-of-experts decision model with 3B active parameters for typed decisions over text and JSON.

nace-ai/drex-v2.0choicescorenoul

Try this model Back to models

MODEL PROFILE

Nace.AI

MODEL ID

nace-ai/drex-v2.0

STRUCTURED OUTPUT

choice

score

noul

The larger successor to Drex v1.5 uses the same state and typed-questions contract.

01 / Workbench

Try Decisions API with your own data

Try OpenAI Decisions API with GPT-6 Luna, or choose another decision model. Edit the input, define typed questions, and inspect the results before connecting the workflow to your backend.

Live requests require sign-in and use your available account credits.

Workbench

Example library

What do you want to decide?

Choose a scenario to load editable input and rules. Loading an example uses no credits.

Examples load into the current draft only; no configurations or run history are saved.

ModelInput format

State

Give the selected model the context shared by every question.

Text

Input state

All questions share this context and are answered independently.

Questions

Define up to eight typed questions for the same state.

3 / 8

3. Run decision

Run the decision request.

Result preview

Subject: Charged twice again!! Hi — this is the SECOND month in a row I've been billed twice for the Pro plan. I already emailed last month and nobody replied. I run my whole business on this. If it's not refunded today I'm cancelling and disputing the charge with my bank.

↓One input → multiple structured decisions

Click “Generate decisions” to see typed output with probabilities.

Results are returned in a structured format so you can connect them to your application logic.

WHERE IT FITS

A model page for a clear decision boundary.

The larger successor to Drex v1.5 uses the same state and typed-questions contract.

Workflow routing

Define the question, receive a typed signal, and connect the result to the next step in your workflow.

Policy checks

Define the question, receive a typed signal, and connect the result to the next step in your workflow.

Structured classification

Define the question, receive a typed signal, and connect the result to the next step in your workflow.

ONE CONTRACT

Use the same decision shape in production.

The model changes, but your integration can keep a state, typed questions, and a predictable response contract.

Read the API docs

REQUEST EXAMPLE

POST /v1/systemone

{
  "model": "nace-ai/drex-v2.0",
  "state": "A customer reports a duplicate charge and needs a fast resolution.",
  "questions": {
    "route": {
      "type": "choice",
      "criteria": {
        "billing": "send to billing support",
        "account": "send to account support",
        "urgent": "escalate for immediate review"
      }
    },
    "urgent": {
      "type": "noul",
      "instructions": "Does this request need attention now?"
    }
  }
}