Mandeep Bal

Heroku is launching automatic prompt caching starting December 18, 2025. Prompt caching delivers a notable, zero-effort performance increase for Heroku Managed Inference and Agents . Enabled by default, this feature is designed to deliver significantly faster responses for common workloads. We have taken a pragmatic approach and currently only enabled this to cache system prompts and tool definition, and not user messages or conversation history. You can disable caching for any request by setting X-Heroku-Prompt-Caching: false.