Sonnet 4.5
Sonnet 4.5是Anthropic推出的Claude系列大型语言模型之一，属于Sonnet级别（介于轻量级Haiku与高性能Opus之间）。该模型具备较强的自然语言理解、多轮对话与代码生成能力，在性能与响应效率之间取得平衡，适用于复杂对话、内容生成及编程辅助等多种应用场景。
Timeline (last 90 days)
Sonnet 4.5 exhibits "context anxiety": when it senses it is approaching the context limit, it rushes to wrap up tasks hastily, requiring the Harness to add a context reset mechanism.
In the Reddit developer community, some users described Sonnet 4.5's interaction behavior as "sassy af."
v1.11.0 marks the deprecation of Sonnet 4.5 in the Chores (routine maintenance) section, meaning Sonnet 4.5-related configurations have been deprecated at the client level.
Sonnet 4.5 has been released and is supported in Claude Code starting from version 2.1.257, with a context window of 1 million tokens.
In Gateway, the Alias still points to the old version of the model, and the new model can only be used by manually specifying the name.
Bedrock Agent Core uses the Sonnet 4.5 model by default in demonstrations.
On Sonnet 4.5 with a 200K token window, approximately 40% of the context is used solely for system prompts.
Claude Code's Sonnet 4.5 has a 200,000-token context window, of which approximately 40% is solely system prompts
Claude Code's Sonnet 4.5 has a context window of 200,000 tokens.
All Facts (7)
Sonnet 4.5 exhibits "context anxiety": when it senses it is approaching the context limit, it rushes to wrap up tasks hastily, requiring the Harness to add a context reset mechanism.
50%Unverifiedv1.11.0 marks the deprecation of Sonnet 4.5 in the Chores (routine maintenance) section, meaning Sonnet 4.5-related configurations have been deprecated at the client level.
50%UnverifiedIn Gateway, the Alias still points to the old version of the model, and the new model can only be used by manually specifying the name.
50%UnverifiedOn Sonnet 4.5 with a 200K token window, approximately 40% of the context is used solely for system prompts.
50%UnverifiedClaude Code's Sonnet 4.5 has a 200,000-token context window, of which approximately 40% is solely system prompts
50%UnverifiedClaude Code's Sonnet 4.5 has a context window of 200,000 tokens.
50%UnverifiedSonnet 4.5 has been released and is supported in Claude Code starting from version 2.1.257, with a context window of 1 million tokens.
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