AI BriefingClaude Code Prompt Overhaul
Key point
The Claude Code system prompt revised its file-reading and REPL rules.
Details
In v2.1.124, a reminder was added to re-read files when current content is needed, even if the diff is missing due to exceeding the snippet budget.
The harness instructions were restructured to specify an introduction phrase and a security-note insertion point instead of calling the core-identity function. The rules for using the REPL tool were also clarified: thenable shorthand is auto-awaited only at return time, and must be awaited first before being used in string concatenation, template literals, or as an argument to another call.
In v2.1.126, the system reminder to re-check each file for malware after a Read tool call was removed.
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