Clef and Clef-flash
Cloudflare released Clef and Clef-flash, open-weight decision models under Apache 2.0 that return probabilities for typed answers, hosted on Workers AI and Hugging Face.
These are the first models trained by the Workers AI team. They answer yes/no, choice and score questions with probabilities instead of text. Clef is post-trained from Qwen3.8-27B and Clef-flash from Qwen3.5-9B, with a non-autoregressive decision step after one prefill pass. They accept images, have a 64k context window and are compatible with the Jev API. Cloudflare also announced an RL fine-tuning product for Clef.
- Date
- Thursday 1 October 2026
- Lab
- Cloudflare
- Kind
- open-weights
- Access
- open weights
- Price
- $0.24 per million tokens for Clef on Workers AI
Figures
| Measure | Value | Measured by |
|---|---|---|
| BFCL case exact | 98.47 (Clef), 98.76 (Clef-flash), 95.75 (Jev) Jev Decision Index, self-reported | company |
| Median latency | 209.3 ms (Clef), 38.8 ms (Clef-flash), 524.1 ms (Jev) 43 eval benchmarks | company |
| Context window | 64k tokens The Register says Jev also handles 64k per request, but its state plus longest question is limited to 32k | company |
| Price per million tokens | $0.24 (Clef) The Register says Jev is $0.042 | The Register |
Benchmark scores are self-reported and have not been reproduced on the official Jev Decision Index.
Sources
- blog.cloudflare.com/clef-decision-models/
- theregister.com/ai-and-ml/2026/10/01/cloudflare-tries-to-outplay-jev-with-open-weight-clef
- marktechpost.com/2026/10/01/cloudflare-releases-clef-and-clef-flash/
This record was checked and corrected against its sources on 8 October 2026. How we check