A longer alternative set of instructions for how Claude talks to you, not yet in use

Claude Code sends Claude a built-in set of instructions, called the system prompt, before your conversation starts. One part of it, "Communicating with the user", now has a longer alternative version. Claude Code uses that version only when a particular check passes. Otherwise it behaves as before.

The alternative version covers:

• Writing for a teammate who is slightly out of the loop
• Opening the final answer with a short summary of the outcome
• Dropping filler words such as "real" and "honest"

Alongside it are further new sections:

• Delivering work
• Corrections
• Handing tasks to subagents (helper agents that Claude starts to work on part of a task)
• Descriptions of each place Claude Code can run: terminal, vscode, desktop, web, mobile, slack, scheduled, github_action, cowork and sdk
• Background Session
• Context management
• Focus mode

In the standard prompt captures, none of the prompt Claude receives has changed, so this version is not in use by default.