# Drex 1.5 vs OpenAI Decisions API

> OpenAI Decisions scores 71.5 (BB) to Drex 1.5's 69.7 (B) for decision models. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/nace-drex-vs-openai-decisions-api
- Markdown: https://www.anchorterminal.com/compare/nace-drex-vs-openai-decisions-api.md (~2,700 tokens)
- Slim: https://www.anchorterminal.com/compare/nace-drex-vs-openai-decisions-api.min.md (~830 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/nace-drex-vs-openai-decisions-api.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: 2026-10-10

OpenAI Decisions API scores 71.5 (BB) on agent readiness against Drex 1.5's 69.7 (B), and leads in 5 of 7 scored categories. Drex 1.5 leads on reliability and payments & pricing. Both do decision models.

- Drex 1.5: grade B, 69.7/100, rank #172 of 954. Markdown https://www.anchorterminal.com/tools/nace-drex.md · JSON https://www.anchorterminal.com/api/v1/tools/nace-drex.json
- OpenAI Decisions API: grade BB, 71.5/100, rank #123 of 954. Markdown https://www.anchorterminal.com/tools/openai-decisions-api.md · JSON https://www.anchorterminal.com/api/v1/tools/openai-decisions-api.json
- Best decision models for AI agents: https://www.anchorterminal.com/best/decision-models/index.md
- All 91 decisions comparisons: https://www.anchorterminal.com/compare/decision-models/index.md

## Which one, for what

### 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 53
- Payments & pricing, 40 against 30

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.

### OpenAI Decisions API (BB)

Good for: High-volume yes or no checks, routing among fixed options and rubric scoring over text and images, for teams already on an OpenAI key.

Ahead on:
- Security & auth, 83 against 65
- Maintenance & community, 77 against 65
- Transparency & trust, 83 against 63

Also in its favour:
- Agent-ready, a grade of BB or better

Watch for: Public beta released on 6 October 2026. The guide expects general availability in the coming weeks and gives no date


## Score by category

| Category | Weight | Drex 1.5 | OpenAI Decisions API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 53 | Drex 1.5 +27 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 88 | 89 | OpenAI Decisions API +1 |
| Agent ergonomics | 13% (16.2 this run) | 85 | 87 | OpenAI Decisions API +2 |
| Security & auth | 14% (17.5 this run) | 65 | 83 | OpenAI Decisions API +18 |
| Payments & pricing | 10% (12.5 this run) | 40 | 30 | Drex 1.5 +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 65 | 77 | OpenAI Decisions API +12 |
| Transparency & trust | 7% (8.8 this run) | 63 | 83 | OpenAI Decisions API +20 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **69.7 · B** | **71.5 · BB** | |

## Facts side by side

| Fact | Drex 1.5 | OpenAI Decisions API |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Nace AI, Inc. (Nace.AI) | OpenAI |
| Hosted endpoint | `https://console.nace.ai/v1/systemone` | `https://api.openai.com/v1/decisions` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Freemium | Pay per use |
| Price for decision models | not published | $0.10 per 1M tokens |
| x402 | no | no |
| Licence | 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. | Proprietary service under OpenAI's services agreement. The official SDKs are Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-28 | 2026-10-06 |
| Terms last updated |  | couldn't be read |
| Privacy policy last updated |  | couldn't be read |
| Customer content may train models |  | couldn't be read |
| Terms restrict automated access |  | couldn't be read |
| Terms restrict benchmarking |  | couldn't be read |
| Terms or service can change without notice |  | couldn't be read |
| Arbitration or class-action waiver |  | couldn't be read |
| Popularity | 318 npm/wk, 156 PyPI/wk | 32k stars |

## Verdicts

**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.

**OpenAI Decisions API.** Typed predicate, choice and score answers with probabilities, up to 200 questions a call, at $0.10 per million input tokens with no output charge. It is a public beta released on 6 October 2026, with one model alias, no dated snapshot, no Batch route and no SLA found.

## Before you call either

### 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.

### OpenAI Decisions API

1. Put independent questions about one input in a single `questions` array. Send a separate request when a question depends on an earlier answer
2. Check each answer's `type` before reading it. A question can come back as `refusal` while the others in the same request are answered
3. Encode images as base64 data URLs. Hosted URLs and `file_id` inputs are rejected
4. Give a `choice` question a fallback value such as `other`, and set thresholds from your own labelled examples
5. Use Python SDK 3.26.0 or JavaScript 7.30.0 or later, and follow `Retry-After` on 429 and 503

## Questions

### Which is better for AI agents, Drex 1.5 or OpenAI Decisions API?

OpenAI Decisions API scores 71.5 (BB) on agent readiness against Drex 1.5's 69.7 (B), and leads in 5 of 7 scored categories. Drex 1.5 leads on reliability and payments & pricing.

### Do Drex 1.5 and OpenAI Decisions API need an API key?

Both need an API key.

### Can an agent call Drex 1.5 and OpenAI Decisions API without installing anything?

Yes. Drex 1.5 has a hosted endpoint at https://console.nace.ai/v1/systemone and OpenAI Decisions API at https://api.openai.com/v1/decisions.


## For agents

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

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