# Celeris-1 Decision vs Drex 1.5

> Drex 1.5 scores 69.7 (B) to Celeris-1 Decision's 49.3 (D) for decision models. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/celeris-1-decision-vs-nace-drex
- Markdown: https://www.anchorterminal.com/compare/celeris-1-decision-vs-nace-drex.md (~2,650 tokens)
- Slim: https://www.anchorterminal.com/compare/celeris-1-decision-vs-nace-drex.min.md (~780 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/celeris-1-decision-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: 2026-10-10

Drex 1.5 scores 69.7 (B) on agent readiness against Celeris-1 Decision's 49.3 (D), and leads in every scored category. Both do decision models.

- Celeris-1 Decision: grade D, 49.3/100, rank #798 of 954. Markdown https://www.anchorterminal.com/tools/celeris-1-decision.md · JSON https://www.anchorterminal.com/api/v1/tools/celeris-1-decision.json
- 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
- 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

### Celeris-1 Decision (D)

Good for: Multimodal classification, routing and bounded decisions with probabilities and optional explanations

Watch for: Early-access terms and capacity-dependent workspace activation

### 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 40
- Schema & documentation, 88 against 60
- Agent ergonomics, 85 against 80
- Security & auth, 65 against 45
- Payments & pricing, 40 against 20
- Maintenance & community, 65 against 40
- Transparency & trust, 63 against 53

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 | Celeris-1 Decision | Drex 1.5 | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 40 | 80 | Drex 1.5 +40 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 60 | 88 | Drex 1.5 +28 |
| Agent ergonomics | 13% (16.2 this run) | 80 | 85 | Drex 1.5 +5 |
| Security & auth | 14% (17.5 this run) | 45 | 65 | Drex 1.5 +20 |
| Payments & pricing | 10% (12.5 this run) | 20 | 40 | Drex 1.5 +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 40 | 65 | Drex 1.5 +25 |
| Transparency & trust | 7% (8.8 this run) | 53 | 63 | Drex 1.5 +10 |
| Negative events | ≤15 | 0 | -2 | |
| **Total** | | **49.3 · D** | **69.7 · B** | |

## Facts side by side

| Fact | Celeris-1 Decision | Drex 1.5 |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Celeris (Marqo Inc) | Nace AI, Inc. (Nace.AI) |
| Hosted endpoint | `https://inference.celeris.ai/celeris-1-decision/v1/systemone` | `https://console.nace.ai/v1/systemone` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Pay per use | Freemium |
| Price for decision models | free | not published |
| x402 | no | no |
| Licence | Proprietary hosted model under Celeris terms of service | 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 | yes | yes |
| Last release | 2026-10-08 | 2026-09-28 |
| Terms last updated | 2026-09-08 |  |
| Privacy policy last updated | 2026-07-23 |  |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | not found in the text |  |
| Terms restrict benchmarking | yes |  |
| Terms or service can change without notice | not found in the text |  |
| Arbitration or class-action waiver | not found in the text |  |
| Popularity | none | 318 npm/wk, 156 PyPI/wk |

## Verdicts

**Celeris-1 Decision.** Typed probabilities, image inputs and optional explanations suit routing and classification inside an agent. Both System One and OpenAI Decisions request formats are documented. The service remains early access under its terms, activation can queue, and prepaid credit expires after 30 days. The published accuracy and latency figures are Celeris measurements, not Anchor Terminal tests.

**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

### Celeris-1 Decision

1. Use the decision model path and matching model field. This model has no chat, Responses or models endpoint.
2. Use at most 512 questions per request, or 64 with explanations. Both endpoints reject streaming.
3. Preserve x_celeris in a custom Jev SDK response model when reading explanations. The default response type drops it.
4. Retry 429 with Retry-After and backoff. Stop on 402 until workspace credit is replenished.
5. Read usage.input_tokens for cost, including images and request overhead. Track credit expiry separately from token consumption.

### 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, Celeris-1 Decision or Drex 1.5?

Drex 1.5 scores 69.7 (B) on agent readiness against Celeris-1 Decision's 49.3 (D), and leads in every scored category.

### Do Celeris-1 Decision and Drex 1.5 need an API key?

Both need an API key.

### Can an agent call Celeris-1 Decision and Drex 1.5 without installing anything?

Yes. Celeris-1 Decision has a hosted endpoint at https://inference.celeris.ai/celeris-1-decision/v1/systemone and Drex 1.5 at https://console.nace.ai/v1/systemone.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/celeris-1-decision-vs-nace-drex.json, and with the fewest tokens: https://www.anchorterminal.com/compare/celeris-1-decision-vs-nace-drex.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "celeris-1-decision", "b": "nace-drex"}`. From a terminal: `anchor compare celeris-1-decision nace-drex`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/celeris-1-decision.json and https://www.anchorterminal.com/api/v1/tools/nace-drex.json

## Other comparisons with Celeris-1 Decision or Drex 1.5

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