--- title: Introducing Clef: our open-source decision models, and... description: Cloudflare has released Clef and Clef-flash, open-source decision models hosted on Workers AI, designed for fast, deterministic structured classification... canonical: https://daily.dev/posts/introducing-clef-our-open-source-decision-models-and-new-rl-fine-tuning-platform-otmxhxg4e twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Introducing Clef: our open-source decision models, and new RL fine-tuning platform | daily.dev og:description: Cloudflare has released Clef and Clef-flash, open-source decision models hosted on Workers AI, designed for fast, deterministic structured classification... og:url: https://daily.dev/posts/introducing-clef-our-open-source-decision-models-and-new-rl-fine-tuning-platform-otmxhxg4e og:image: https://api.daily.dev/og/posts/oTMxhXg4E.png og:image:alt: Introducing Clef: our open-source decision models, and new RL fine-tuning platform og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Introducing Clef: our open-source decision models, and new RL fine-tuning platform **[Cloudflare](https://daily.dev/sources/cloudflare)** · 12 min read · 0 upvotes · 0 comments ## Summary Cloudflare has released Clef and Clef-flash, open-source decision models hosted on Workers AI, designed for fast, deterministic structured classification useful in agentic workflows. Built on a Qwen backbone with a non-autoregressive, prefill-only scoring approach, Clef claims higher accuracy and lower latency than Typesafe AI's Jev model and general-purpose LLMs like gpt-oss-120b across dozens of benchmarks. The models are Jev-API compatible, licensed under Apache 2.0, and downloadable from Hugging Face. Cloudflare is also launching a reinforcement learning fine-tuning service, starting with a hands-on forward-deployed engineer team and eventually a self-serve platform built on AI Gateway, Containers, and a new Trainer component for redeploying fine-tuned models on Workers AI. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What is Cloudflare's Clef decision model and how does it compare to Typesafe AI's Jev? Clef and Clef-flash are Cloudflare-trained decision models hosted on Workers AI that produce typed, probability-based classifications and are fully API-compatible with Jev. Clef has a vision encoder for image classification (Jev is text-only), a 64k context window versus Jev's 32k, and beat Jev in 3 of 4 evals on Typesafe's own eval suite, with lower median latency across 43 benchmarks. _Teams weighing decision-model options for agentic pipelines can track comparisons like this on daily.dev._ ### How much faster is Cloudflare's Clef model than a general-purpose LLM for domain classification? In Cloudflare's Threat Intelligence domain classification workflow, Clef took 2.2 seconds to fetch, render, and classify a website, versus 4.7 seconds for gpt-oss-120b, which also returned only two classifications compared to Clef's broader output. This roughly doubles throughput for agentic pipelines needing fast, structured decisions. _Developers optimizing agent latency can follow benchmarks like this on daily.dev._ ### What base model and training approach does Cloudflare use to build the Clef decision model? Clef is built on a Qwen backbone (Qwen3.8-27B for Clef, Qwen3.5-9B for Clef-flash) that is frozen while jointly optimizing a routing head with rank-256 low-rank adapters. Training uses label-smoothed cross-entropy plus Brier loss for probability calibration, synthetic datasets with permuted field orders, and a custom reinforcement learning method called RLCD for calibrated, non-autoregressive decision scoring. _Engineers evaluating custom classifier training approaches can dig into details like this on daily.dev._ ## Similar posts on daily.dev - [Cloudflare’s AI Platform: an inference layer designed for agents](https://daily.dev/posts/cloudflare-s-ai-platform-an-inference-layer-designed-for-agents-70umlv07w) · Cloudflare · 1 upvotes · 0 comments - [Cloudflare Workers AI: run LLMs without API keys](https://daily.dev/posts/cloudflare-workers-ai-run-llms-without-api-keys-sxc7e3lma) · Flavio Copes · 1 upvotes · 0 comments - [One year later: Sovereign AI and the fight for choice](https://daily.dev/posts/one-year-later-sovereign-ai-and-the-fight-for-choice-xjyth832x) · Cloudflare · 0 upvotes · 0 comments --- Tags: [#open-source](https://daily.dev/tags/open-source), [#cloudflare](https://daily.dev/tags/cloudflare), [#reinforcement-learning](https://daily.dev/tags/reinforcement-learning) [View this post on daily.dev](https://daily.dev/posts/introducing-clef-our-open-source-decision-models-and-new-rl-fine-tuning-platform-otmxhxg4e) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Introducing Clef: our open-source decision models, and new RL fine-tuning platform","url":"https://daily.dev/posts/introducing-clef-our-open-source-decision-models-and-new-rl-fine-tuning-platform-otmxhxg4e","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/introducing-clef-our-open-source-decision-models-and-new-rl-fine-tuning-platform-otmxhxg4e"},"datePublished":"2026-10-01T15:35:17.940Z","dateModified":"2026-10-02T01:33:33.675Z","description":"Cloudflare has released Clef and Clef-flash, open-source decision models hosted on Workers AI, designed for fast, deterministic structured classification...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7ed68c578f7b64d571006d09b66f84d2?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7ed68c578f7b64d571006d09b66f84d2?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Cloudflare","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Cloudflare","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/38522e1d11354cd6b7af66f9d4316735","url":"https://daily.dev/sources/cloudflare"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/introducing-clef-our-open-source-decision-models-and-new-rl-fine-tuning-platform-otmxhxg4e","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"open-source,cloudflare,reinforcement-learning","timeRequired":"PT12M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Cloudflare","item":"https://daily.dev/sources/cloudflare"},{"@type":"ListItem","position":3,"name":"Introducing Clef: our open-source decision models, and new RL fine-tuning platform"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/introducing-clef-our-open-source-decision-models-and-new-rl-fine-tuning-platform-otmxhxg4e#faq","mainEntity":[{"@type":"Question","name":"What is Cloudflare's Clef decision model and how does it compare to Typesafe AI's Jev?","acceptedAnswer":{"@type":"Answer","text":"Clef and Clef-flash are Cloudflare-trained decision models hosted on Workers AI that produce typed, probability-based classifications and are fully API-compatible with Jev. 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