Context branching cuts exfiltration from 31-50% down to 0-7%.

APPA replaces permanent context contamination with engine-managed branching: when the agent is about to acquire unvetted data, the system spawns an isolated trajectory to inspect it and returns only a bounded derivative through a trusted sanitizer to an unchanged parent context. Formally a two-monoid algebra over security labels and shared event logs. The suppression numbers are the headline but the better finding for builders is that on three of four models, branching recovered utility that ordinary taint tracking destroys. Taint tracking makes your agent dumber; branching mostly doesn't.