Request 2 caches its request content (not the response) changedbuild-with-claude/prompt-caching
Nearest release: v2.1.314, published under an hour after this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
Recorded here
Lines+2added
Lines−2removed
From line
612
where the diff opens
First seen
14 Aug 2026
this site's first read of the page
Recorded edits34to this page, all time
The whole hunk
from line 612, old and new numbered
/
from line 612
612612**Cache breakpoints themselves don’t add any cost.** You are only charged for:
613613
614614* **Cache writes:** When new content is written to the cache (25% more than base input tokens for 5-minute TTL)
615* **Cache reads:** When cached content is used (10% of base input token price, or 2.5% on Claude Fable 5.1 and Claude Mythos 5.1, and 5% on Claude Opus 5.5 and Claude Sonnet 5.5)
615* **Cache reads:** When cached content is used (10% of base input token price, with [per-model exceptions](https://platform.claude.com/docs/en/build-with-claude/prompt-caching#pricing))
616616* **Regular input tokens:** For any uncached content
617617
618618Adding more `cache_control` breakpoints doesn’t increase your costs; you still pay the same amount based on what content is actually cached and read. The breakpoints give you control over what sections can be cached independently.
from line 689
689689| **Thinking parameters** | Model-specific | Model-specific | ✘ | The thinking configuration (mode, and `budget_tokens` in extended mode) is rendered into the prompt, so changing it always invalidates message blocks; tool and system caches are also invalidated on models that render the configuration ahead of them. See [Thinking and prompt caching](https://platform.claude.com/docs/en/build-with-claude/thinking#thinking-and-prompt-caching). |
690690| **Effort setting** | Model-specific | Model-specific | ✘ | Changing the [`output_config.effort`](https://platform.claude.com/docs/en/build-with-claude/effort) value always invalidates message blocks, with the same model-specific effect on tool and system caches as thinking parameters. Setting effort explicitly to the model’s default is equivalent to omitting it and does not invalidate. On models that support [per-message effort](https://platform.claude.com/docs/en/build-with-claude/effort#change-effort-mid-conversation-beta), an effort change carried in a `role: "system"` message inside `messages` leaves the cached prefix intact. |
691691| **Non-tool results passed to requests with thinking** | ✓ | ✓ | Model-specific | On Opus 4.5+, Sonnet 4.6+, and Haiku 5.5, thinking blocks are preserved by default, so the cache remains valid (✓). On earlier Opus/Sonnet models and Haiku models through Claude Haiku 4.5, all previously-cached thinking blocks are stripped from context, and any messages that follow those thinking blocks are removed from the cache (✘). For more details, see [Caching with thinking blocks](https://platform.claude.com/docs/en/build-with-claude/prompt-caching#caching-with-thinking-blocks). |
692| **Dropped thinking blocks** | ✓ | ✓ | ✘ | When the API drops a Claude Fable 5.1, Claude Mythos 5.1, Claude Opus 5.5, Claude Sonnet 5.5, or Claude Haiku 5.5 thinking block that isn’t [preserved](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-thinking) on that request, the cached prefix changes from that block’s position onward on that request. Blocks the receiving model can read, passed back unchanged, keep the cache intact. |
692| **Dropped thinking blocks** | ✓ | ✓ | ✘ | When the API drops a Claude 5.1 or later model’s thinking block that isn’t [preserved](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-thinking) on that request, the cached prefix changes from that block’s position onward on that request. Blocks the receiving model can read, passed back unchanged, keep the cache intact. |
693693
694694On models that support [mid-conversation tool changes](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages#mid-conversation-tool-changes), the `inline-tools-2026-09-15` beta header lets you add a tool, or change a tool’s definition, partway through a conversation without editing `tools`. Send the definition in a `tool_addition` block in a mid-conversation system message and leave `tools` exactly as you first sent it. The cached prefix still matches, so only the appended message is processed as new input. The one exception is a `tools` array with no non-deferred tool, where the first tool defined this way costs one full cache miss on that request. See [Define tools in a message](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages#define-tools-in-a-message-beta).
695695
No line in this hunk matches that.