---
title: "PromptCacheBreakpoint"
---

Marks an explicit prompt-cache boundary on this content block (OpenAI-style). Everything through the block carrying this marker is part of the candidate cached prefix. Supported natively by OpenAI GPT-5.6 and newer; on providers that use Anthropic-style `cache_control`, OpenRouter converts the marker to that format automatically.


## Fields

| Field                                                                              | Type                                                                               | Required                                                                           | Description                                                                        |
| ---------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- |
| `mode`                                                                             | [components.PromptCacheBreakpointMode](../components/promptcachebreakpointmode.mdx) | :heavy_check_mark:                                                                 | N/A                                                                                |