# Decision 3.0 vs Drex 1.5

> Drex 1.5 scores 69.7 (B) to Decision 3.0's 63.1 (B) for decision models. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/decision-3-vs-nace-drex
- Markdown: https://www.anchorterminal.com/compare/decision-3-vs-nace-drex.md (~2,700 tokens)
- Slim: https://www.anchorterminal.com/compare/decision-3-vs-nace-drex.min.md (~780 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/decision-3-vs-nace-drex.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-12

Drex 1.5 scores 69.7 (B) on agent readiness against Decision 3.0's 63.1 (B), and leads in 5 of 7 scored categories. Decision 3.0 leads on payments & pricing and maintenance & community. Both do decision models.

- Decision 3.0: grade B, 63.1/100, rank #413 of 965. Markdown https://www.anchorterminal.com/tools/decision-3.md · JSON https://www.anchorterminal.com/api/v1/tools/decision-3.json
- Drex 1.5: grade B, 69.7/100, rank #173 of 965. Markdown https://www.anchorterminal.com/tools/nace-drex.md · JSON https://www.anchorterminal.com/api/v1/tools/nace-drex.json
- Best decision models for AI agents: https://www.anchorterminal.com/best/decision-models/index.md
- All 105 decisions comparisons: https://www.anchorterminal.com/compare/decision-models/index.md

## Which one, for what

### Decision 3.0 (B)

Good for: Self-hosted typed decisions over screenshots, documents and short video as well as text, where open weights matter.

Ahead on:
- Payments & pricing, 60 against 40
- Maintenance & community, 82 against 65

Also in its favour:
- No key needed to call it
- Open source

Watch for: Released on 10 October 2026, with five tagged releases of each model by 11 October

### Drex 1.5 (B)

Good for: Routing, triage and yes or no gates inside an agent, where the caller supplies the options and acts on the probabilities. Suited to hosted use at a low per-token price, or to open weights where the licence fits.

Ahead on:
- Reliability, 80 against 58
- Schema & documentation, 88 against 70
- Agent ergonomics, 85 against 72
- Security & auth, 65 against 56
- Transparency & trust, 63 against 45

Also in its favour:
- A hosted endpoint, with nothing to install

Watch for: The rank 1 claim comes from Nace's own run on Decision Index 0.3.1, and Drex is not on the public board for 0.3 or 0.2.1.


## Score by category

| Category | Weight | Decision 3.0 | Drex 1.5 | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 58 | 80 | Drex 1.5 +22 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 70 | 88 | Drex 1.5 +18 |
| Agent ergonomics | 13% (16.2 this run) | 72 | 85 | Drex 1.5 +13 |
| Security & auth | 14% (17.5 this run) | 56 | 65 | Drex 1.5 +9 |
| Payments & pricing | 10% (12.5 this run) | 60 | 40 | Decision 3.0 +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 82 | 65 | Decision 3.0 +17 |
| Transparency & trust | 7% (8.8 this run) | 45 | 63 | Drex 1.5 +18 |
| Negative events | ≤15 | 0 | -2 | |
| **Total** | | **63.1 · B** | **69.7 · B** | |

## Facts side by side

| Fact | Decision 3.0 | Drex 1.5 |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | vLLM Semantic Router Team | Nace AI, Inc. (Nace.AI) |
| Hosted endpoint | no (local only) | `https://console.nace.ai/v1/systemone` |
| Transports | HTTP | HTTP |
| Auth | None | API key |
| Pricing | Free | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 for the weights and the bundled runtime, built on Apache-2.0 Qwen3.5 and Qwen3.8 bases | Hosted API under the Nace AI Terms of Service, last updated 5 May 2026. Weights under the Nace AI Open RAIL-M licence (modified, version 1.0, October 2026), which is not an open-source licence. Businesses above $1 million in revenue or funding need a separate commercial licence, and competing products are excluded. The bundled code/kev package, derived from Jared Palmer's Kev (https://github.com/jaredpalmer/kev), and the GitHub repository are Apache-2.0, and the agent skill is MIT. |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2026-10-11 | 2026-09-28 |
| Terms last updated | no document linked |  |
| Privacy policy last updated | no document linked |  |
| Customer content may train models |  |  |
| Terms restrict automated access |  |  |
| Terms restrict benchmarking |  |  |
| Terms or service can change without notice |  |  |
| Arbitration or class-action waiver |  |  |
| Popularity | none | 318 npm/wk, 156 PyPI/wk |

## Verdicts

**Decision 3.0.** Open Apache-2.0 decision models that read images and video as well as text and answer several typed questions in one call, with a probability per option and tagged Hub releases. They are two days old, need a GPU and `trust_remote_code`, drop Vela's set and span types, and publish no calibration figures.

**Drex 1.5.** The hosted endpoint has a public OpenAPI document, published limits and pinned model versions, at $0.05 per million input tokens with no output charge. The #1 under 10B claim rests on Nace's own run, since Drex is absent from both public boards. Weights carry Open RAIL-M, which requires a commercial licence above $1 million in revenue or funding.

## Before you call either

### Decision 3.0

1. Pin a tag or commit with `revision=` when loading from the Hub. Each model had five tagged releases on 10 and 11 October
2. Send images and videos to `d3_server.py` as base64 data URLs only. The server refuses paths and http URLs with 422
3. Set `DECISION_API_KEY` before binding the bundled server beyond 127.0.0.1. It is open otherwise
4. Turn on `permutation_average=True` when routing must not depend on option order. It is off by default
5. Expect one request at a time from the bundled server. Use the router's model runtime for queued serving

### Drex 1.5

1. Call https://console.nace.ai/v1/systemone with Authorization: Bearer nace_sk_..., and pin model drex-v1.5 rather than drex-latest in production.
2. Stop on 402 insufficient_credit or 402 payment_required until credit is topped up or the unpaid invoice is paid.
3. Retry 429 and 529 after retry-after-ms. On a 422 for an unknown model, use one of the ids the error message lists.
4. Keep state below 131,072 tokens and the body below 1,048,576 bytes, and send at most 512 questions per request.
5. Keep the key on a server. A key in browser code is exposed, and the /v1 routes send no Access-Control-Allow-Origin header.
6. Check usage.input_tokens and the usage CSV after retries, since /v1/systemone documents no idempotency key.

## Questions

### Which is better for AI agents, Decision 3.0 or Drex 1.5?

Drex 1.5 scores 69.7 (B) on agent readiness against Decision 3.0's 63.1 (B), and leads in 5 of 7 scored categories. Decision 3.0 leads on payments & pricing and maintenance & community.

### Do Decision 3.0 and Drex 1.5 need an API key?

Decision 3.0 needs no key. Drex 1.5 needs an API key.

### Can an agent call Decision 3.0 and Drex 1.5 without installing anything?

No hosted endpoint is listed for Decision 3.0. Drex 1.5 has a hosted endpoint at https://console.nace.ai/v1/systemone.

### Are Decision 3.0 and Drex 1.5 open source?

Decision 3.0 is open source (Apache-2.0 for the weights and the bundled runtime, built on Apache-2.0 Qwen3.5 and Qwen3.8 bases). No open-source release is listed for Drex 1.5.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/decision-3-vs-nace-drex.json, and with the fewest tokens: https://www.anchorterminal.com/compare/decision-3-vs-nace-drex.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "decision-3", "b": "nace-drex"}`. From a terminal: `anchor compare decision-3 nace-drex`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/decision-3.json and https://www.anchorterminal.com/api/v1/tools/nace-drex.json

## Other comparisons with Decision 3.0 or Drex 1.5

- [Celeris-1 Decision vs Decision 3.0](https://www.anchorterminal.com/compare/celeris-1-decision-vs-decision-3.md)
- [Celeris-1 Decision vs Drex 1.5](https://www.anchorterminal.com/compare/celeris-1-decision-vs-nace-drex.md)
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- [Decision 3.0 vs Microsoft-Decision-1](https://www.anchorterminal.com/compare/decision-3-vs-microsoft-decision-1.md)
- [Decision 3.0 vs OpenAI Decisions API](https://www.anchorterminal.com/compare/decision-3-vs-openai-decisions-api.md)
- [Decision 3.0 vs pplx-decider](https://www.anchorterminal.com/compare/decision-3-vs-pplx-decider.md)
- [Decision 3.0 vs Strands Decider 2B](https://www.anchorterminal.com/compare/decision-3-vs-strands-decider.md)
- [Decision 3.0 vs Jev](https://www.anchorterminal.com/compare/decision-3-vs-typesafe-jev.md)
- [Decision 3.0 vs Vela 2.0](https://www.anchorterminal.com/compare/decision-3-vs-vela.md)
- [GLiClass vs Drex 1.5](https://www.anchorterminal.com/compare/gliclass-vs-nace-drex.md)
- [Kev vs Drex 1.5](https://www.anchorterminal.com/compare/jaredpalmer-kev-vs-nace-drex.md)
- [Liquid d1 vs Drex 1.5](https://www.anchorterminal.com/compare/liquid-d1-vs-nace-drex.md)
- [Microsoft-Decision-1 vs Drex 1.5](https://www.anchorterminal.com/compare/microsoft-decision-1-vs-nace-drex.md)
- [Drex 1.5 vs OpenAI Decisions API](https://www.anchorterminal.com/compare/nace-drex-vs-openai-decisions-api.md)
- [Drex 1.5 vs pplx-decider](https://www.anchorterminal.com/compare/nace-drex-vs-pplx-decider.md)
- [Drex 1.5 vs Strands Decider 2B](https://www.anchorterminal.com/compare/nace-drex-vs-strands-decider.md)
- [Drex 1.5 vs Jev](https://www.anchorterminal.com/compare/nace-drex-vs-typesafe-jev.md)
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