Domain 5Projects, Context & Advanced Configuration
Project Instructions
TL;DR
Persistent background instructions that shape Claude's behaviour for every chat within a specific project.
Definition
Persistent background instructions that shape Claude's behaviour for every chat within a specific project. They function as a system prompt — write them once and they apply automatically to every new conversation. This eliminates repeating your role, preferences, and formatting rules at the start of each session.
Exam Context
Know that Project Instructions consume tokens from the context window (the same window your conversation needs) but do not count against your message quota. Overly long instructions crowd out space for actual work.