extended-thinking changedbuild-with-claude/extended-thinking
Nearest release: v2.1.293, published 2 hours 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+6added
Lines−6removed
From line
290
where the diff opens
First seen
14 Aug 2026
this site's first read of the page
Recorded edits17to this page, all time
The whole hunk
from line 290, old and new numbered
/
from line 290
290290
291291## Interleaved thinking in manual mode
292292
293Interleaved thinking lets Claude think between tool calls within a single assistant turn, reasoning about each tool result before deciding what to do next. For the concept, the turn structure, and how it behaves on adaptive-thinking models, see [interleaved thinking](https://platform.claude.com/docs/en/build-with-claude/thinking#interleaved-thinking) in the thinking overview. This section covers how to enable it when you use manual `type: "enabled"` thinking.
293Interleaved thinking lets Claude think between tool calls within a single assistant turn, reasoning about each tool result before determining what to do next. For the concept, the turn structure, and how it behaves on adaptive-thinking models, see [interleaved thinking](https://platform.claude.com/docs/en/build-with-claude/thinking#interleaved-thinking) in the thinking overview. This section covers how to enable it when you use manual `type: "enabled"` thinking.
294294
295On Claude Opus 4.5, Claude Sonnet 4.5, and earlier Claude 4 models, add the `interleaved-thinking-2025-05-14` [beta header](https://platform.claude.com/docs/en/api/beta-headers) to your API request.
295On Claude Opus 4.5, Claude Sonnet 4.5 (deprecated), and earlier Claude 4 models, add the `interleaved-thinking-2025-05-14` [beta header](https://platform.claude.com/docs/en/api/beta-headers) to your API request.
296296
297297The 4.6 generation splits in manual mode:
298298
from line 349
349349
350350## Migrating to adaptive thinking
351351
352If your model supports only extended thinking (Claude Sonnet 4.5, Claude Opus 4.5, Claude Haiku 4.5, and earlier Claude 4 models), no action is needed now: adaptive thinking is not available there, and `type: "adaptive"` [returns a 400 error](https://platform.claude.com/docs/en/build-with-claude/thinking-troubleshooting#error-thinking-type-adaptive). Keep `budget_tokens` until you move to a model that supports adaptive thinking, then apply the mapping that follows.
352If your model supports only extended thinking (Claude Sonnet 4.5 (deprecated), Claude Opus 4.5, Claude Haiku 4.5, and earlier Claude 4 models), no action is needed now: adaptive thinking is not available there, and `type: "adaptive"` [returns a 400 error](https://platform.claude.com/docs/en/build-with-claude/thinking-troubleshooting#error-thinking-type-adaptive). Keep `budget_tokens` until you move to a model that supports adaptive thinking, then apply the mapping that follows.
353353
354354You need to migrate off `type: "enabled"` if:
355355
from line 386
386386
387387`effort: "high"` matches the API default; it appears here only to show where the depth control now lives, and omitting it produces identical behavior.
388388
389Expect a behavioral difference, not just a syntax change. With a fixed budget, Claude thinks on every request. With adaptive thinking, Claude decides whether and how much to think on each request, and at lower [effort](https://platform.claude.com/docs/en/build-with-claude/effort) settings it may skip thinking entirely on easy inputs. You can also remove the `interleaved-thinking-2025-05-14` beta header after migrating: adaptive thinking interleaves automatically, and the Claude API ignores the header on these models. Thinking block preservation changes too: Claude Opus 4.5 and models numbered 4.6 and higher keep prior turns' thinking blocks in context and bill them as input, where Claude Sonnet 4.5, Claude Haiku 4.5, and earlier models stripped them; see [thinking block preservation by model](https://platform.claude.com/docs/en/build-with-claude/thinking#thinking-block-preservation-by-model).
389Expect a behavioral difference, not just a syntax change. With a fixed budget, Claude thinks on every request. With adaptive thinking, Claude determines whether and how much to think on each request, and at lower [effort](https://platform.claude.com/docs/en/build-with-claude/effort) settings it may skip thinking entirely on easy inputs. You can also remove the `interleaved-thinking-2025-05-14` beta header after migrating: adaptive thinking interleaves automatically, and the Claude API ignores the header on these models. Thinking block preservation changes too: Claude Opus 4.5 and models numbered 4.6 and higher keep prior turns' thinking blocks in context and bill them as input, where Claude Sonnet 4.5 (deprecated), Claude Haiku 4.5, and earlier models stripped them; see [thinking block preservation by model](https://platform.claude.com/docs/en/build-with-claude/thinking#thinking-block-preservation-by-model).
390390
391391Switching modes is a thinking-configuration change, so the first request after the switch invalidates cache breakpoints, as described in [Prompt caching in manual mode](https://platform.claude.com/docs/en/build-with-claude/extended-thinking#extended-thinking-with-prompt-caching).
392392
from line 400
400400 </Card>
401401
402402 <Card title="Steering thinking" icon="compass" href="https://platform.claude.com/docs/en/build-with-claude/thinking-steering-and-cost">
403 Let Claude decide when and how much to think on each request.
403 Let Claude determine when and how much to think on each request.
404404 </Card>
405405
406406 <Card title="Thinking in tool and multi-turn workflows" icon="wrench" href="https://platform.claude.com/docs/en/build-with-claude/thinking-tool-workflows">
No line in this hunk matches that.