Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
One change · api

Create a Message changed

api/beta/messages/create

Nearest release: v2.1.272, published 5 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+89added
Lines−87removed
From line 3,906 where the diff opens
First seen 14 Aug 2026 this site's first read of the page
Recorded edits13to this page, all time

The whole hunk

from line 3906, old and new numbered
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from line 3906
39063906 
39073907- `temperature: optional number`
39083908 
3909 **Deprecated**: Deprecated. Models released after Claude Opus 4.6 do not support setting temperature. A value of 1.0 of will be accepted for backwards compatibility, all other values will be rejected with a 400 error.
3909 **Deprecated**: Deprecated. Models released after Claude Opus 4.6 do not support setting temperature. A value of 1.0 will be accepted for backwards compatibility, all other values will be rejected with a 400 error.
39103910 
39113911 Amount of randomness injected into the response.
39123912 
from line 5397
53975397 
53985398 minimum: 0
53995399 
5400 - `model: Model`
5400 - `model: Model or null`
54015401 
54025402 The model that will complete your prompt.
54035403 
from line 5495
54955495 
54965496 Token usage for the fallback-model attempt of a server-side fallback request.
54975497 
5498 Produced in place of a `message` entry for whichever hop served the
5499 response. A declined hop produces the existing `message` entry. Whether
5500 a fallback model served the response is signalled by the presence of this
5501 entry in `usage.iterations`.
5498 The terminal entry of a fallback-served turn: when a fallback hop's
5499 output is the returned message, the entry for the iteration that
5500 completed it carries this type in place of `message`. A declined hop
5501 and the serving hop's earlier tool-loop iterations produce `message`
5502 entries. Whether a fallback model served the response is signalled by
5503 the presence of this entry in `usage.iterations`.
55025504 
55035505 - `type: "fallback_message"`
55045506