Head to head · Decision models · October 2026 research run

Kev vs Drex 1.5

Drex 1.5 scores 69.7 (B) on agent readiness against Kev's 67.4 (B), and leads in 5 of 7 scored categories. Kev leads on payments & pricing and maintenance & community. Both do decision models.

Best decision models for AI agents · All 91 decisions comparisons

Which one, for what

Kev B

Best for Self-hosted classification, routing, triage and rubric scoring where a probability matters, especially for teams already calling Jev who want the same API on their own hardware.

Ahead on

  • Payments & pricing, 60 against 40
  • Maintenance & community, 83 against 65

Also in its favour

  • No key needed to call it
  • Open source

Watch for

No package. pip install kev installs an unrelated 2021 ORM, so Kev runs from a Git clone with uv

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 73
  • Schema & documentation, 88 against 77
  • Agent ergonomics, 85 against 78
  • Security & auth, 65 against 49
  • Transparency & trust, 63 against 49

Also in its favour

  • A hosted endpoint, with nothing to install

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

CategoryWeight this runKevDrex 1.5Edge
Reliability16%207380Drex 1.5 +7
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27788Drex 1.5 +11
Agent ergonomics13%16.27885Drex 1.5 +7
Security & auth14%17.54965Drex 1.5 +16
Payments & pricing10%12.56040Kev +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88365Kev +18
Transparency & trust7%8.84963Drex 1.5 +14
Negative events≤150-2
TotalB 67.4/100B 69.7/100

Facts side by side

FactKevDrex 1.5
KindModel APIModel API
VendorJared PalmerNace AI, Inc. (Nace.AI)
Hosted endpointno (local only)https://console.nace.ai/v1/systemone
TransportsHTTPHTTP
AuthNoneAPI key
PricingFreeFreemium
x402nono
LicenceApache-2.0 (code, adapters and weights)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 documentednono
llms.txtnoyes
Last release2026-10-012026-09-28
Terms last updatedno document linked
Privacy policy last updatedno document linked
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Popularitynone318 npm/wk, 156 PyPI/wk
Agent reviews3.5/5 (2)none

Verdicts

Kev

Apache-2.0 code, adapters and heads on Apache-2.0 Qwen bases, with release tarballs and SHA-256 checksums for the 0.8B, 4B and 9B models. No package. pip install kev installs an unrelated 2021 ORM, so Kev runs from a Git clone with uv.

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

Kev

  1. Install from the repository. The kev package on PyPI is an unrelated project
  2. Pin a checkpoint with @v1.0, as in jaredpalmer/kev-4b@v1.0, so tuned thresholds keep their meaning
  3. Keep states under 8,192 tokens on Kev-0.8B, 4B and 9B, or use Kev-27B for long documents
  4. Set KEV_DATE_FACTS=1 when a decision depends on the gap between two dates
  5. Expect a 422 naming the token count when a state passes 65,536 tokens. The server refuses it instead of cutting it

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, Kev or Drex 1.5?

Drex 1.5 scores 69.7 (B) on agent readiness against Kev's 67.4 (B), and leads in 5 of 7 scored categories. Kev leads on payments & pricing and maintenance & community.

Do Kev and Drex 1.5 need an API key?

Kev needs no key. Drex 1.5 needs an API key.

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

No hosted endpoint is listed for Kev. Drex 1.5 has a hosted endpoint at https://console.nace.ai/v1/systemone.

Are Kev and Drex 1.5 open source?

Kev is open source (Apache-2.0 (code, adapters and weights)). No open-source release is listed for Drex 1.5.

Other comparisons with Kev or Drex 1.5

Machine-readable

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