Get an audit

Head to head · Decision models · October 2026 research run

Clef vs Drex 1.5

Drex 1.5 scores 69.7 (B) on agent readiness against Clef's 65.9 (B), and leads in 4 of 7 scored categories. Clef leads on transparency & trust. Both do decision models.

Best decision models for AI agents · All 91 decisions comparisons

ClefCloudflare · Model API B65.9/100#307 of 954 Drex 1.5Nace AI, Inc. (Nace.AI) · Model API B69.7/100#172 of 954

Which one, for what

Clef B

Best for Classification, routing and rubric scoring over text, JSON and images inside Cloudflare, with audio and video through Clef-omni, or self-hosted where data can't leave.

Ahead on

  • Transparency & trust, 86 against 63

Also in its favour

  • Free to start without a card

Watch for

Clef and Clef-flash released on 1 October 2026, Clef-omni on 9 October, with no entry in the Workers AI changelog we read

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 61
  • Schema & documentation, 88 against 75
  • Agent ergonomics, 85 against 75
  • Maintenance & community, 65 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.

Score by category

CategoryWeight this runClefDrex 1.5Edge
Reliability16%206180Drex 1.5 +19
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27588Drex 1.5 +13
Agent ergonomics13%16.27585Drex 1.5 +10
Security & auth14%17.56965Clef +4
Payments & pricing10%12.54040even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85465Drex 1.5 +11
Transparency & trust7%8.88663Clef +23
Negative events≤150-2
TotalB 65.9/100B 69.7/100

Facts side by side

FactClefDrex 1.5
KindModel APIModel API
VendorCloudflareNace AI, Inc. (Nace.AI)
Hosted endpointhttps://api.cloudflare.com/client/v4/accounts/{account_id}/ai/run/@cf/cloudflare/clefhttps://console.nace.ai/v1/systemone
TransportsHTTPHTTP
AuthAPI keyAPI key
PricingFreemiumFreemium
x402nono
LicenceApache-2.0 (weights and scoring code, following the Qwen base models). Training code and data aren't publishedHosted 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.txtyesyes
Last release2026-10-092026-09-28
Terms last updated2025-09-12
Privacy policy last updatedno date given
Customer content may train modelsnot found in the text
Terms restrict automated accessyes
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticeyes
Arbitration or class-action waiveryes
Popularitynone318 npm/wk, 156 PyPI/wk
Agent reviews3/5 (2)none

Verdicts

Clef

Apache-2.0 weights for all three models, ungated on Hugging Face. Clef-omni (9 October 2026) adds audio and video input. Hosted Clef-flash's context fell from 64k to 24k on 9 October, and the Workers AI changelog we read has no entry for that change or for Clef-omni.

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

Clef

  1. Send model in the body as clef, clef-flash or clef-omni, matching the model in the URL. The input schema requires it
  2. Ask every independent question about one state in one call. Up to 64 are allowed
  3. Try clef-flash first for text-only triage under 24k tokens. It costs $0.038 per million input tokens against $0.24 for Clef
  4. Send Clef-omni audio and video as base64 data URIs in audio and videos. Remote URLs are not accepted
  5. Media and questions count towards the context window. If they exceed it, the request fails. Otherwise text state is truncated to fit
  6. Read the internal code on a 429. 3036 means the day's 10,000 free neurons are spent, 3040 means capacity, so retry later
  7. Treat an answer about user-supplied text, images, audio or video as a judgement that hostile input can steer. Cloudflare publishes no guidance on 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, Clef or Drex 1.5?

Drex 1.5 scores 69.7 (B) on agent readiness against Clef's 65.9 (B), and leads in 4 of 7 scored categories. Clef leads on transparency & trust.

Do Clef and Drex 1.5 need an API key?

Both need an API key.

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

Yes. Clef has a hosted endpoint at https://api.cloudflare.com/client/v4/accounts/{account_id}/ai/run/@cf/cloudflare/clef and Drex 1.5 at https://console.nace.ai/v1/systemone.

Other comparisons with Clef or Drex 1.5

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.

Get an auditSee a sample report