claude-haiku-5-5
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.
Claude Code now recognises claude-haiku-5-5, with a 1M-token context window, its own pricing and a fallback to claude-haiku-4-5
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.293.
In the changelogs
5Releases whose published page names claude-haiku-5-5.
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v2.1.295
Haiku 5.5 gets a medium-effort thinking default in a model list
A model list now includes
claude-haiku-5-5with thinking set to medium effort, and the model appears in more places than beforefound in this entry's text, named in this entry
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v2.1.293
Claude Code now knows about a Haiku 5.5 model
Claude Code now recognises
claude-haiku-5-5, with a 1M-token context window, its own pricing and a fallback toclaude-haiku-4-5named in this entry, found in this entry's text
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v2.1.293
The
haikumodel name now means Haiku 5.5 on the Anthropic APIThe
haikualias now picksclaude-haiku-5-5on Anthropic's own API, while Bedrock, Vertex and other providers stay onclaude-haiku-4-5named in this entry, found in this entry's text
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v2.1.293
The Haiku model name now points to Claude Haiku 5.5
Claude Code now names Haiku as Claude Haiku 5.5 (
claude-haiku-5-5) instead of Haiku 4.5, and prices it with its own ratenamed in this entry, found in this entry's text
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v2.1.293
Claude Code recognises Claude Haiku 5.5
Claude Code now knows the claude-haiku-5-5 model, its short name haiku-5-5, and a Vertex region variable for it
named in this entry, found in this entry's text
First cited
6The earliest release whose published evidence quoted claude-haiku-5-5 was v2.1.293, 7 Oct 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.