Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
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One change · api

Create a Message changed

api/messages/create

Nearest release: v2.1.258, published 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+18added
Lines−22removed
From line 1,070 where the diff opens
First seen 14 Aug 2026 this site's first read of the page
Recorded edits10to this page, all time

The whole hunk

from line 1070, old and new numbered
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lines
from line 1070
10701070 
10711071 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
10721072 
1073 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
1073 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
10741074 
10751075 The model that will complete your prompt.
10761076 
10771077 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
10781078 
1079 - `"claude-fable-5-1"`
1080 
1081 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
1082 
1083 - `"claude-mythos-5-1"`
1084 
1085 Our most capable model for cybersecurity and biology research, available through trusted access programs
1086 
10791087 - `"claude-sonnet-5"`
10801088 
10811089 High-performance model for coding and agents
from line 1673
16651673 
16661674 - `type: "browser_toolset_20260801"`
16671675 
1668 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
1669 
1670 - `"direct"`
1671 
1672 - `"code_execution_20250825"`
1673 
1674 - `"code_execution_20260120"`
1675 
1676 - `"code_execution_20260521"`
1677 
16781676 - `cache_control: optional CacheControlEphemeral or null`
16791677 
16801678 Create a cache control breakpoint at this content block.
from line 2105
21072105 
21082106 - `type: "computer_toolset_20260801"`
21092107 
2110 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
2111 
2112 - `"direct"`
2113 
2114 - `"code_execution_20250825"`
2115 
2116 - `"code_execution_20260120"`
2117 
2118 - `"code_execution_20260521"`
2119 
21202108 - `cache_control: optional CacheControlEphemeral or null`
21212109 
21222110 Create a cache control breakpoint at this content block.
from line 3743
37553743 
37563744 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
37573745 
3758 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
3746 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
37593747 
37603748 The model that will complete your prompt.
37613749 
37623750 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
3751 
3752 - `"claude-fable-5-1"`
3753 
3754 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
3755 
3756 - `"claude-mythos-5-1"`
3757 
3758 Our most capable model for cybersecurity and biology research, available through trusted access programs
37633759 
37643760 - `"claude-sonnet-5"`
37653761