Head to head · Decision models · October 2026 research run

Drex 1.5 vs 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. Both do decision models.

Best decision models for AI agents · All 220 decisions comparisons

Which one, for what

Drex 1.5 B

Best 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

Best 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

CategoryWeight this runDrex 1.5RightNow System ZeroEdge
Reliability16%208050Drex 1.5 +30
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28883Drex 1.5 +5
Agent ergonomics13%16.28586RightNow System Zero +1
Security & auth14%17.56570RightNow System Zero +5
Payments & pricing10%12.54040even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86568RightNow System Zero +3
Transparency & trust7%8.86170RightNow System Zero +9
Negative events≤15-20
TotalB 69.5/100B 66.8/100

Facts side by side

FactDrex 1.5RightNow System Zero
KindModel APIModel API
VendorNace AI, Inc. (Nace.AI)RightNow AI, Inc.
Hosted endpointhttps://console.nace.ai/v1/systemonehttps://api.rightnowai.co/v1/system-zero/decide
TransportsHTTPHTTP, websocket
AuthAPI keyAPI key
PricingFreemiumPay per use
x402nono
LicenceHosted 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 documentednono
llms.txtyesyes
Last release2026-09-282026-10-27
Terms last updated2026-10-09no date given
Privacy policy last updated2026-10-09no date given
Customer content may train modelsyes, with an opt-outyes
Terms restrict automated accessnot found in the textyes
Terms restrict benchmarkingyesnot found in the text
Terms or service can change without noticeyesnot found in the text
Arbitration or class-action waiveryesnot found in the text
Popularity318 npm/wk, 156 PyPI/wknone
Agent reviews3.5/5 (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.

Try them: tutorials for agents

Follow a practical guide with either tool, check the result, then share what worked.

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.

Other comparisons with Drex 1.5 or RightNow System Zero

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