Head to head · Decision models · October 2026 research run

Drex 1.5 vs SPEV

Drex 1.5 scores 69.5 (B) on agent readiness against SPEV's 51.1 (D), and leads in every scored category. Both do decision models.

Best decision models for AI agents · All 136 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 45
  • Schema & documentation, 88 against 81
  • Agent ergonomics, 85 against 76
  • Security & auth, 65 against 33
  • Payments & pricing, 40 against 30
  • Maintenance & community, 65 against 49
  • Transparency & trust, 61 against 54

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.

SPEV D

Best for Typed decisions over raw audio, such as end-of-turn detection, call triage and flagging, plus text and single images, hosted or self-hosted.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

Published on 14 October 2026, with no service record, no status page and no API changelog

Score by category

CategoryWeight this runDrex 1.5SPEVEdge
Reliability16%208045Drex 1.5 +35
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28881Drex 1.5 +7
Agent ergonomics13%16.28576Drex 1.5 +9
Security & auth14%17.56533Drex 1.5 +32
Payments & pricing10%12.54030Drex 1.5 +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86549Drex 1.5 +16
Transparency & trust7%8.86154Drex 1.5 +7
Negative events≤15-2-2
TotalB 69.5/100D 51.1/100

Facts side by side

FactDrex 1.5SPEV
KindModel APIModel API
VendorNace AI, Inc. (Nace.AI)Sprag
Hosted endpointhttps://console.nace.ai/v1/systemonehttps://api.sprag.ai/v1/decisions
TransportsHTTPHTTP
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.Apache-2.0 (weights and inference code, following the Qwen3-Omni base). Training code and data aren't published
Read-only variant documentednono
llms.txtyesyes
Last release2026-09-282026-10-14
Terms last updated2026-10-092026-09-01
Privacy policy last updated2026-10-092026-08-01
Customer content may train modelsyes, with an opt-outyes, with an opt-out
Terms restrict automated accessnot found in the textnot found in the text
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

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.

SPEV

SPEV answers typed questions over text, audio or an image in one call, with a public OpenAPI schema and Apache-2.0 weights on Hugging Face. It is a day old, has an 8,192-token context, no status page or changelog, and Sprag's terms let it train on API content unless the customer opts out by email.

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.

SPEV

  1. Send model: "spev" to POST https://api.sprag.ai/v1/decisions with a bearer key. /v1/systemone returns 410
  2. Ask every question about one piece of evidence in one request. Answers come back in question order
  3. Send audio as base64 in input_audio with format, not as a data URL, and at most one image across all messages
  4. Keep evidence and questions under 8,192 tokens. Over the limit returns 400 model_limit_exceeded
  5. Back off on 429 and 503 for Retry-After seconds. Limits are 60 requests a minute per organisation by default
  6. Handle an answer of type refusal, which carries no probabilities

Questions

Which is better for AI agents, Drex 1.5 or SPEV?

Drex 1.5 scores 69.5 (B) on agent readiness against SPEV's 51.1 (D), and leads in every scored category.

Do Drex 1.5 and SPEV need an API key?

Both need an API key.

Can an agent call Drex 1.5 and SPEV without installing anything?

Yes. Drex 1.5 has a hosted endpoint at https://console.nace.ai/v1/systemone and SPEV at https://api.sprag.ai/v1/decisions.

Other comparisons with Drex 1.5 or SPEV

Machine-readable

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