Claude Fable 5.2 now available on AI Gateway

Claude Fable 5.2 from Anthropic is now available on Vercel’s AI Gateway, expanding the platform’s model lineup. The model is designed for open-ended technical tasks, including coding, reasoning, and vision, and can operate unattended on long or ambiguous workflows. It functions as either an orchestrator, delegating simpler tasks to smaller models, or as an advisor consulted by other Claude models for complex problems. Fable 5.2 also delivers faster output generation and clearer communication compared to earlier versions.

Access to Fable 5.2 requires enabling data retention, as Anthropic does not support Zero Data Retention for this model. Prompts and completions are stored for 30 days and are not used for training. Teams with Zero Data Retention enabled will receive an error when attempting to use Fable 5.2, and requests will not be processed. To bypass classifier rejections, users can configure model fallbacks by specifying a models array in providerOptions.gateway, allowing AI Gateway to sequentially try alternative models.

Fable 5.2 can be called through multiple interfaces, including the AI SDK, Chat Completions, Responses, and Anthropic Messages APIs, or via a coding agent connected to AI Gateway. The model name to use is anthropic/claude-fable-5.2, with automatic fallback to Opus 5.5 and Sonnet 5.5 if the cybersecurity classifier declines a request. This fallback mechanism applies consistently across all AI Gateway API formats.

AI Gateway serves as a unified interface for model access, usage tracking, and cost management, while providing features like custom reporting, Zero Data Retention support, and routing rules. The platform reflects provider pricing without markup and does not charge a platform fee on inference, including Bring Your Own Key requests. Users can explore all available language models on AI Gateway, including Fable 5.2, through the model playground.