nace-ai/

drex-v2.0

$0.06 / 1M tokens

Drex v2.0 is a 35B mixture-of-experts decision model (3B active) from Nace.AI. Given a state (text or JSON) and typed questions (yes/no, multiple choice, or ordinal score), it returns a calibrated probability for every option in a single forward pass, with no text generation. It is TypeSafe System One compatible, handles contexts up to 131K tokens, and ranks #1 on Decision Index 0.2.1 with 60.78, ahead of Drex v1.5 and Jev 1.13.0.

Public

Zero retention

131,072

Project License

api

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Model Information

Drex v2.0

Drex v2.0 is a decision model from Nace.AI. You give it a state (text or JSON) and typed questions, and it returns a calibrated probability for every option in a single forward pass. It generates no text, and it never answers with an option you did not supply.

Mixture of experts: about 35B parameters, 3B active per token, built on Qwen3.6-35B-A3B, with a trained pointer head.
#1 on Decision Index 0.2.1 (60.78), ahead of Drex v1.5 and Jev 1.13.0.
Context up to 131,072 tokens for the state plus each question. Long states are filtered down to their relevant parts automatically.
TypeSafe System One compatible: the same request and response as Jev, so the TypeSafe SDK works by changing its base URL.

Question types

Type	You send	You get back
`noul`	a yes/no question, with optional `criteria.true` / `criteria.false`	`noul`, the probability of "yes"
`choice`	options as `criteria` (name → description or `null`), 1-255 options	`choice` (the most likely option), `probabilities` per option, and `confidence`
`score`	ordered levels as a `criteria` list, 1-255 levels	`score` (the expected level), `probabilities` per level, `legend`, and `confidence`

One request can ask many questions about the same state. The state is read once and billed once per request.

Example

curl https://api.deepinfra.com/v1/decisions \
  -H "Authorization: Bearer $DEEPINFRA_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "nace-ai/drex-v2.0",
    "state": {"ticket": "I was charged twice for order A-104. Please refund the duplicate today."},
    "questions": {
      "team": {"type": "choice", "instructions": "Which team handles this?",
               "criteria": {"billing": "Charges and refunds", "shipping": "Delivery", "other": null}},
      "refund": {"type": "noul", "instructions": "Does the customer ask for a refund?"},
      "urgency": {"type": "score", "instructions": "How urgent is this request?",
                  "criteria": ["Routine", "Time-sensitive", "Immediate"]}
    }
  }'
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The same API is served at https://api.deepinfra.com/v1/systemone. To use the TypeSafe Python SDK, set TYPESAFE_BASE_URL=https://api.deepinfra.com/typesafe and model="nace-ai/drex-v2.0".

Performance

Figures reported by Nace.AI on the model card.

Decision Index 0.2.1 (full suite, 150,317 requests)

Rank	Model	Index	Knowledge & Reasoning	Language	Retrieval	Tools	Arts
1	Drex v2.0	60.78	47.7	65.9	62.9	76.0	49.1
2	Drex v1.5	58.28	44.2	62.5	62.0	75.3	45.1
3	Jev 1.13.0	57.91	51.4	62.0	55.4	75.1	37.7

Area columns are chance-corrected skill × 100. Drex v2.0 is ahead of Jev on 21 of the 38 index benchmarks and on 4 of 5 areas.

Other benchmarks

Benchmark	Drex v2.0	Drex v1.5	Jev 1.13.0
DecideBench v1.1 (400 contrastive decisions)	96.3%	90.0%	98.0% (AI Space)
JevBench (231 public items)	85.7%	85.7%	86.6%
Email classification, AUC	0.984	0.972	0.981
Email classification, caught at 5% false positives	89.4%	80.3%	86.4%
Game arena vs Jev (256 games)	60.9% score (132 W / 48 D / 76 L)	56.8%	—

License and use restrictions

Drex v2.0 is © Nace.AI, Inc. and is provided under the Nace AI Open RAIL-M License (modified). By using this model you agree to its use-based restrictions (Attachment A), including:

No fully automated decisions without meaningful human review in employment, credit, housing, insurance, healthcare, education, immigration or law enforcement.
No discrimination based on legally protected characteristics.
No medical, legal or financial advice or decisions without qualified human oversight.
No military, weapons, mass-surveillance, fraud, scam or spam use.

Read the full license before use. Drex and Nace are trademarks of Nace.AI, Inc.