HELPER 03 · SUBAGENT ISOLATION

Where do the 200-file tokens live?

Same work, two contexts. Subagents don't shrink total spend — they move where the spend lands.

Tokens sitting in main-session context: parent reads versus subagent returns synthesis Two horizontal bars. The parent-reads bar is about 600,000 tokens, drawn in the expensive cost color with diagonal hatching. The subagent-returns bar is about 2,000 tokens, a thin strip in the cool cache color with a dotted pattern. Parent reads 200 files itself All file bodies stay in main context for the rest of the session ~600K tok Subagent reads, returns synthesis Only the summary lives in main context — files stayed in the subagent's window ~2K tok summary 300x smaller main-context footprint same underlying research work 0 200K 400K 600K Tokens sitting in main-session context
Parent path
~600K tok
Re-processed every turn until /split
Subagent path
~2K tok
Files never touch the main window