Create a Message Batch changedapi/beta/messages/batches/create
Nearest release: v2.1.322, published 2 hours 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.
Recorded here
Lines+18added
Lines−2removed
From line
131
where the diff opens
First seen
14 Aug 2026
this site's first read of the page
Recorded edits31to this page, all time
The whole hunk
from line 131, old and new numbered
/
from line 131
131131
132132 - `"webhooks-2026-10-07"`
133133
134 - `"admin-user-sign-out-2026-10-08"`
135
134136 - `"message-threads-2026-08-12"`
135137
136138 - `"analytics-usage-cost-2026-08-24"`
from line 3148
31463148
31473149 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
31483150
3151 - `"claude-fable-5-2"`
3152
3153 Built for the most ambitious work in coding, enterprise workflows, and the sciences
3154
3155 - `"claude-mythos-5-2"`
3156
3157 Built for the most demanding cybersecurity and life sciences research, available through verification programs
3158
31493159 - `"claude-haiku-5-5"`
31503160
31513161 Fastest model for high-volume, real-time tasks
from line 3506
34963506 Accepted in `messages[].content` and not rendered into the prompt; not
34973507 validated against the request's `fallbacks` chain or top-level `model`.
34983508
3499 Echo the assistant turn back verbatim, including this block in its
3509 When you send the assistant turn back, keep this block in its
35003510 original position. The block marks the boundary between content produced
35013511 before and after a fallback hop, and the server relies on that boundary
35023512 to validate the turn: when thinking runs flank the boundary, omitting
from line 3513
35033513 the block merges them into one span the server cannot validate (the
35043514 request is rejected), and moving it into the middle of a single run is
35053515 likewise rejected; between non-thinking blocks the block's placement has
3506 no validation effect.
3516 no effect on thinking validation.
3517
3518 Some blocks from before the turn's final `fallback` block must be left
3519 out when you send the turn back, and no `tool_result` is sent for a
3520 `tool_use` block you left out.
3521
3522 See the [refusals and fallback guide](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback?sdk_languages=http#continuing-the-conversation) to learn which blocks to keep.
35073523
35083524 - `type: "fallback"`
35093525
No line in this hunk matches that.