claude-opus-4-5
A Claude Code model, read out of the shipped bundle. No mined inventory carries it: everything below comes from what this site has written about it.
Writing a file you have not read is now decided locally by model and permissions, not a server flag.
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.228.
In the changelogs
5Releases whose published page names claude-opus-4-5.
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v2.1.269
New model-name whitelist helper recognizes Opus 4.5 and Haiku 4.5
Model-name whitelist helper now recognizes claude-opus-4-5 and claude-haiku-4-5 as current model names
found in this entry's text, named in this entry
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v2.1.228
Write-before-Read rule is now decided locally, not by a remote flag
Writing a file you have not read is now decided locally by model and permissions, not a server flag.
found in this entry's text
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v2.1.200
Model ID Error Messages Now Suggest Alternatives
found in this entry's text
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v2.0.59
Extended Thinking Mode for claude-opus-4-5
found in this entry's text
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v2.0.51
Model Detection Extended
found in this entry's text
First cited
1The earliest release whose published evidence quoted claude-opus-4-5 was v2.1.269, 11 Sep 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table below.
Presence across releases
0The miner has never read a build containing this name. It is here because a changelog entry of ours names it, which is evidence that it existed and not evidence of which releases carried it. The inventory starts at v2.1.138 and everything older than that was never mined.
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the model does. All models.