Context Engineering

This gives you the actual operations to prevent that: write critical state to files so it survives compaction, select with surgical precision instead of dumping whole modules, compress at task boundaries before you hit 95% and lose coherence, and isolate heavy work to subagents so your main session stays clean. The token budget breakdowns are practical, the compaction triggers make sense, and the anti-patterns section will save you from the grep-then-read-entire-file mistake everyone makes. Basically the missing manual for keeping Claude sharp across long sessions.