Introducing Clef: our open-source decision models, and new RL fine-tuning platform

Summary

Cloudflare introduced Clef and Clef-flash, open-source decision models hosted on Workers AI for classification and agentic workflows, plus a reinforcement learning platform for fine-tuning decision models with developers' own data.

Key facts

• Clef and Clef-flash are open-source decision models hosted on Workers AI.
• The models target high-speed classification and agentic workflows.
• A new reinforcement learning platform lets developers fine-tune decision models using their own data.
• Cloudflare announced the models and platform on 2026-10-01.

Why it matters

Developers can run open decision models on Workers AI and fine-tune them with their own data through the new reinforcement learning platform, rather than relying solely on closed models.