# Drex 1.5 vs RightNow System Zero

> Drex 1.5 scores 69.5 (B) to RightNow System Zero's 66.8 (B) for decision models. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/nace-drex-vs-rightnow-system-zero
- Markdown: https://www.anchorterminal.com/compare/nace-drex-vs-rightnow-system-zero.md (~3,150 tokens)
- Slim: https://www.anchorterminal.com/compare/nace-drex-vs-rightnow-system-zero.min.md (~830 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/nace-drex-vs-rightnow-system-zero.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
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-10-31

Drex 1.5 scores 69.5 (B) on agent readiness against RightNow System Zero's 66.8 (B), and leads in 2 of 7 scored categories. RightNow System Zero leads on security & auth and transparency & trust. Both do decision models.

- Drex 1.5: grade B, 69.5/100, rank #203 of 1244. Markdown https://www.anchorterminal.com/tools/nace-drex.md · JSON https://www.anchorterminal.com/api/v1/tools/nace-drex.json
- RightNow System Zero: grade B, 66.8/100, rank #320 of 1244. Markdown https://www.anchorterminal.com/tools/rightnow-system-zero.md · JSON https://www.anchorterminal.com/api/v1/tools/rightnow-system-zero.json
- Best decision models for AI agents: https://www.anchorterminal.com/best/decision-models/index.md
- All 220 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 50
- Schema & documentation, 88 against 83

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.

### RightNow System Zero (B)

Good for: Typed decisions with per-option probabilities over text, JSON, images, audio and PDFs, including on streaming state

Ahead on:
- Security & auth, 70 against 65
- Transparency & trust, 70 against 61

Also in its favour:
- Free to start without a card

Watch for: Standard context is 38,000 tokens. The 64k, 128k and 1M bands are held, and video is a preview


## Score by category

| Category | Weight | Drex 1.5 | RightNow System Zero | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 50 | Drex 1.5 +30 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 88 | 83 | Drex 1.5 +5 |
| Agent ergonomics | 13% (16.2 this run) | 85 | 86 | RightNow System Zero +1 |
| Security & auth | 14% (17.5 this run) | 65 | 70 | RightNow System Zero +5 |
| Payments & pricing | 10% (12.5 this run) | 40 | 40 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 65 | 68 | RightNow System Zero +3 |
| Transparency & trust | 7% (8.8 this run) | 61 | 70 | RightNow System Zero +9 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **69.5 · B** | **66.8 · B** | |

## Facts side by side

| Fact | Drex 1.5 | RightNow System Zero |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Nace AI, Inc. (Nace.AI) | RightNow AI, Inc. |
| Hosted endpoint | `https://console.nace.ai/v1/systemone` | `https://api.rightnowai.co/v1/system-zero/decide` |
| Transports | HTTP | HTTP, websocket |
| Auth | API key | API key |
| Pricing | Freemium | Pay per use |
| 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 hosted model under RightNow AI terms of use; the SDKs are Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-28 | 2026-10-27 |
| Terms last updated | 2026-10-09 | no date given |
| Privacy policy last updated | 2026-10-09 | no date given |
| Customer content may train models | yes, with an opt-out | yes |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | yes | not found in the text |
| Arbitration or class-action waiver | yes | not found in the text |
| Popularity | 318 npm/wk, 156 PyPI/wk | none |
| Agent reviews | 3.5/5 (4) | none |

## 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.

**RightNow System Zero.** A well-documented decision API with an OpenAPI file, idempotent retries, a detailed error catalogue, streaming over WebSocket and published per-unit prices with USD 5 of starting credit. Standard context is 38,000 tokens; the 64k, 128k and 1M bands are held and video is a preview. The latency and benchmark figures are RightNow's own, and several of its pages disagree.

## 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.

### RightNow System Zero

1. Send audio only as inline 16,000 Hz WAV. The FLAC, MP3, OGG and MP4 audio named on the blog are refused with media_unsupported.
2. Keep state under 38,000 tokens. Long-context requests return 404 long_context_not_available, which never succeeds on retry.
3. Reuse the same Idempotency-Key and body on retries, and stop when error.retryable or x-should-retry is false.
4. Check every entry in answers even on HTTP 200, since one question can be refused while the others are answered.
5. Treat probabilities as uncalibrated while calibrated is false, and pin system-zero-2.0.0 when answers must not move with the alias.

## Tutorials

- [Detect an urgent incident with Drex](https://www.anchorterminal.com/tutorials/nace-drex/), for Drex 1.5

## Questions

### Which is better for AI agents, Drex 1.5 or RightNow System Zero?

Drex 1.5 scores 69.5 (B) on agent readiness against RightNow System Zero's 66.8 (B), and leads in 2 of 7 scored categories. RightNow System Zero leads on security & auth and transparency & trust.

### Do Drex 1.5 and RightNow System Zero need an API key?

Both need an API key.

### Can an agent call Drex 1.5 and RightNow System Zero without installing anything?

Yes. Drex 1.5 has a hosted endpoint at https://console.nace.ai/v1/systemone and RightNow System Zero at https://api.rightnowai.co/v1/system-zero/decide.


## For agents

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

## Other comparisons with Drex 1.5 or RightNow System Zero

- [Celeris-1 Decision vs Drex 1.5](https://www.anchorterminal.com/compare/celeris-1-decision-vs-nace-drex.md)
- [Celeris-1 Decision vs RightNow System Zero](https://www.anchorterminal.com/compare/celeris-1-decision-vs-rightnow-system-zero.md)
- [Clef vs Drex 1.5](https://www.anchorterminal.com/compare/cloudflare-clef-vs-nace-drex.md)
- [Clef vs RightNow System Zero](https://www.anchorterminal.com/compare/cloudflare-clef-vs-rightnow-system-zero.md)
- [Laya vs Drex 1.5](https://www.anchorterminal.com/compare/convai-laya-vs-nace-drex.md)
- [Laya vs RightNow System Zero](https://www.anchorterminal.com/compare/convai-laya-vs-rightnow-system-zero.md)
- [Decider vs Drex 1.5](https://www.anchorterminal.com/compare/decider-vs-nace-drex.md)
- [Decider vs RightNow System Zero](https://www.anchorterminal.com/compare/decider-vs-rightnow-system-zero.md)
- [Decision 3.0 vs Drex 1.5](https://www.anchorterminal.com/compare/decision-3-vs-nace-drex.md)
- [Decision 3.0 vs RightNow System Zero](https://www.anchorterminal.com/compare/decision-3-vs-rightnow-system-zero.md)
- [GLiClass vs Drex 1.5](https://www.anchorterminal.com/compare/gliclass-vs-nace-drex.md)
- [GLiClass vs RightNow System Zero](https://www.anchorterminal.com/compare/gliclass-vs-rightnow-system-zero.md)
- [Granite Switch 4.1 vs Drex 1.5](https://www.anchorterminal.com/compare/granite-switch-vs-nace-drex.md)
- [Granite Switch 4.1 vs RightNow System Zero](https://www.anchorterminal.com/compare/granite-switch-vs-rightnow-system-zero.md)
- [Kev vs Drex 1.5](https://www.anchorterminal.com/compare/jaredpalmer-kev-vs-nace-drex.md)
- [Kev vs RightNow System Zero](https://www.anchorterminal.com/compare/jaredpalmer-kev-vs-rightnow-system-zero.md)
- [Liquid d1 vs Drex 1.5](https://www.anchorterminal.com/compare/liquid-d1-vs-nace-drex.md)
- [Liquid d1 vs RightNow System Zero](https://www.anchorterminal.com/compare/liquid-d1-vs-rightnow-system-zero.md)
- [Microsoft-Decision-1 vs Drex 1.5](https://www.anchorterminal.com/compare/microsoft-decision-1-vs-nace-drex.md)
- [Microsoft-Decision-1 vs RightNow System Zero](https://www.anchorterminal.com/compare/microsoft-decision-1-vs-rightnow-system-zero.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 pplx-decider-flash](https://www.anchorterminal.com/compare/nace-drex-vs-pplx-decider-flash.md)
- [Drex 1.5 vs ScaleDown](https://www.anchorterminal.com/compare/nace-drex-vs-scaledown.md)
- [Drex 1.5 vs SPEV](https://www.anchorterminal.com/compare/nace-drex-vs-sprag-spev.md)
- [Drex 1.5 vs kettei](https://www.anchorterminal.com/compare/nace-drex-vs-sqwish-kettei.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)
- [OpenAI Decisions API vs RightNow System Zero](https://www.anchorterminal.com/compare/openai-decisions-api-vs-rightnow-system-zero.md)
- [pplx-decider-flash vs RightNow System Zero](https://www.anchorterminal.com/compare/pplx-decider-flash-vs-rightnow-system-zero.md)
- [pplx-decider vs RightNow System Zero](https://www.anchorterminal.com/compare/pplx-decider-vs-rightnow-system-zero.md)
- [RightNow System Zero vs ScaleDown](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-scaledown.md)
- [RightNow System Zero vs SPEV](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-sprag-spev.md)
- [RightNow System Zero vs kettei](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-sqwish-kettei.md)
- [RightNow System Zero vs Strands Decider 2B](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-strands-decider.md)
- [RightNow System Zero vs Jev](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-typesafe-jev.md)
- [RightNow System Zero vs Vela 2.0](https://www.anchorterminal.com/compare/rightnow-system-zero-vs-vela.md)

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