Request 2 caches its request content (not the response) changedbuild-with-claude/prompt-caching
Nearest release: v2.1.293, published an hour before this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
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250250| Claude Sonnet 4.6 | $3 / MTok | $3.75 / MTok | $6 / MTok | $0.30 / MTok | $15 / MTok |
251251| Claude Sonnet 4.5 | $3 / MTok | $3.75 / MTok | $6 / MTok | $0.30 / MTok | $15 / MTok |
252252| Claude Sonnet 4 ([retired, except on Bedrock and Google Cloud](https://platform.claude.com/docs/en/about-claude/model-deprecations)) | $3 / MTok | $3.75 / MTok | $6 / MTok | $0.30 / MTok | $15 / MTok |
253| Claude Haiku 5.5 (for prompts up to 100,000 tokens) | $0.10 / MTok | $0.125 / MTok | $0.20 / MTok | $0.01 / MTok | $0.50 / MTok |
254| Claude Haiku 5.5 (for prompts over 100,000 tokens) | $0.50 / MTok | $0.625 / MTok | $1 / MTok | $0.05 / MTok | $2.50 / MTok |
253255| Claude Haiku 4.5 | $1 / MTok | $1.25 / MTok | $2 / MTok | $0.10 / MTok | $5 / MTok |
254256| Claude Haiku 3.5 ([retired, except on Bedrock and Google Cloud](https://platform.claude.com/docs/en/about-claude/model-deprecations)) | $0.80 / MTok | $1 / MTok | $1.60 / MTok | $0.08 / MTok | $4 / MTok |
255257
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590592**Cache breakpoints themselves don't add any cost.** You are only charged for:
591593
592594* **Cache writes:** When new content is written to the cache (25% more than base input tokens for 5-minute TTL)
593* **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)
595* **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)
594596* **Regular input tokens:** For any uncached content
595597
596598Adding 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.
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603605
604606On the Claude API, [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-on-vertex-ai), and [Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry), the minimum cacheable prompt length is:
605607
606* 512 tokens for Claude Fable 5.1, [Claude Mythos 5.1](https://platform.claude.com/docs/en/models/mythos-5-1/overview), Claude Opus 5.5, Claude Opus 5, Claude Sonnet 5.5, Claude Fable 5, and [Claude Mythos 5](https://platform.claude.com/docs/en/models/mythos-5/overview)
608* 512 tokens for Claude Fable 5.1, [Claude Mythos 5.1](https://platform.claude.com/docs/en/models/mythos-5-1/overview), Claude Opus 5.5, Claude Opus 5, Claude Sonnet 5.5, Claude Fable 5, [Claude Mythos 5](https://platform.claude.com/docs/en/models/mythos-5/overview), and Claude Haiku 5.5
607609* 2,048 tokens for [Claude Mythos Preview](https://anthropic.com/glasswing) and Claude Opus 4.7
608610* 4,096 tokens for Claude Opus 4.6 and Claude Opus 4.5
609611* 1,024 tokens for Claude Opus 4.8, Claude Sonnet 5, Claude Sonnet 4.6, Claude Sonnet 4.5 ([deprecated](https://platform.claude.com/docs/en/about-claude/model-deprecations)), Claude Opus 4.1 ([retired, except on Bedrock and Google Cloud](https://platform.claude.com/docs/en/about-claude/model-deprecations)), Claude Opus 4 ([retired, except on Google Cloud](https://platform.claude.com/docs/en/about-claude/model-deprecations)), and Claude Sonnet 4 ([retired, except on Bedrock and Google Cloud](https://platform.claude.com/docs/en/about-claude/model-deprecations))
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666668| **Images** | ✓ | ✓ | ✘ | Adding/removing images anywhere in the prompt affects message blocks |
667669| **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). |
668670| **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. |
669| **Non-tool results passed to extended thinking requests** | ✓ | ✓ | Model-specific | On Opus 4.5+ and Sonnet 4.6+, thinking blocks are preserved by default, so the cache remains valid (✓). On earlier Opus/Sonnet models and all Haiku models, 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). |
670| **Dropped thinking blocks** | ✓ | ✓ | ✘ | When the API drops a Claude Fable 5.1, Claude Mythos 5.1, Claude Opus 5.5, or Claude Sonnet 5.5 thinking block that isn't [preserved](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-thinking) on that request (for example, one you replay to a model that can't read it), 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. |
671| **Non-tool results passed to extended thinking requests** | ✓ | ✓ | 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). |
672| **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 (for example, one you replay to a model that can't read it), 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. |
671673
672674On 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).
673675
674676<Note>
675 On Claude Fable 5.1, [Claude Mythos 5.1](https://platform.claude.com/docs/en/models/mythos-5-1/overview), Claude Fable 5, [Claude Mythos 5](https://platform.claude.com/docs/en/models/mythos-5/overview), Claude Opus 5.5, Claude Opus 4.8, Claude Opus 5, and Claude Sonnet 5.5, you can add a new system instruction partway through a conversation without invalidating the system or message caches. Append a `{"role": "system"}` message to `messages` instead of editing the top-level `system` field, so the cached prefix stays unchanged. This feature is not available on Claude Sonnet 5. Use the top-level `system` field instead. See [Mid-conversation system messages](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages).
677 On Claude Fable 5.1, [Claude Mythos 5.1](https://platform.claude.com/docs/en/models/mythos-5-1/overview), Claude Fable 5, [Claude Mythos 5](https://platform.claude.com/docs/en/models/mythos-5/overview), Claude Opus 5.5, Claude Opus 4.8, Claude Opus 5, Claude Sonnet 5.5, and Claude Haiku 5.5, you can add a new system instruction partway through a conversation without invalidating the system or message caches. Append a `{"role": "system"}` message to `messages` instead of editing the top-level `system` field, so the cached prefix stays unchanged. This feature is not available on Claude Sonnet 5. Use the top-level `system` field instead. See [Mid-conversation system messages](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages).
676678</Note>
677679
678680### Tracking cache performance
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721723**Cache invalidation patterns:**
722724
723725* Cache remains valid when only tool results are provided as user messages
724* On Opus 4.5+ and Sonnet 4.6+, thinking blocks are preserved by default even when non-tool-result user content is added, so the cache remains valid
725* On earlier Opus/Sonnet models and all Haiku models, cache gets invalidated when non-tool-result user content is added, causing all previous thinking blocks to be stripped from context
726* On Opus 4.5+, Sonnet 4.6+, and Haiku 5.5, thinking blocks are preserved by default even when non-tool-result user content is added, so the cache remains valid
727* On earlier Opus/Sonnet models and Haiku models through Claude Haiku 4.5, cache gets invalidated when non-tool-result user content is added, causing all previous thinking blocks to be stripped from context
726728* This caching behavior occurs even without explicit `cache_control` markers
727729
728730For more details on cache invalidation, see [What invalidates the cache](https://platform.claude.com/docs/en/build-with-claude/prompt-caching#what-invalidates-the-cache).
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750752# Depending on the model, this non-tool-result user block either keeps prior thinking blocks or strips them (see the next paragraph)
751753```
752754
753On earlier Opus/Sonnet models and all Haiku models, all previous thinking blocks are removed from context at this point. On Opus 4.5+ and Sonnet 4.6+, prior thinking blocks are kept by default and remain part of the cached prefix.
755On earlier Opus/Sonnet models and Haiku models through Claude Haiku 4.5, all previous thinking blocks are removed from context at this point. On Opus 4.5+, Sonnet 4.6+, and Haiku 5.5, prior thinking blocks are kept by default and remain part of the cached prefix.
754756
755757For more detailed information, see [Thinking and prompt caching](https://platform.claude.com/docs/en/build-with-claude/thinking#thinking-and-prompt-caching).
756758
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8848862. 1-hour cache write tokens for `(B - A)`.
8858873. 5-minute cache write tokens for `(C - B)`.
886888
887Here are three examples. This depicts the input tokens of 3 requests, each of which has different cache hits and cache misses. Each has a different calculated pricing, shown in the colored boxes, as a result. 
889Here are three examples. This depicts the input tokens of 3 requests, each of which has different cache hits and cache misses. Each has a different calculated pricing, shown in the colored boxes, as a result.
890
891<Frame>
892 
893</Frame>
888894
889895***
890896
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