Opus 4 and Sonnet 4 knowledge cutoffs clarified; Windows Ctrl+Z crash fixed; SDK gains error capture and print mode adds --system-prompt-file.
Changes
4
Total Changes (vs Average)
0.3×
Version Type
Patch
Release Focus
Mixed
Days Since Prior Release
7
Release # This Month
#16 of 23
Bug Fix Ratio
25%
Post-Release Edits
—
Change Category
Ecosystem Impact
Windows has appeared in 3 of the last 10 releases, indicating sustained platform stabilization. SDK makes its first appearance in the lookback window, suggesting early extensibility investment alongside ongoing Windows hardening.
Key Themes
1Opus 4 & Sonnet 4 Model Documentation|3Developer Tooling & Windows Stability
May Help If You've Noticed
Ctrl+Z crashes or freezes Claude Code on Windows
You need to know how current Opus 4 or Sonnet 4's training data is
Error logs disappear when running Claude Code programmatically via SDK
You need to supply a custom system prompt in headless or print mode
Changes in Claude Code v1.0.55
Added1 change
•SDK: Added ability to capture error logging
Fixed1 change
•Windows: fixed Ctrl+Z crash
Other2 changes
•Clarified knowledge cutoff for Opus 4 and Sonnet 4 models
•Add --system-prompt-file option to override system prompt in print mode