PII Redaction
Domain: Security
Motivation
When enabled, the gateway hashes user IDs and strips phone numbers from session context before it reaches the model.
Concrete Example
On Telegram: user phone +852-9123-4567 is hashed to a1b2c3 before the model sees it. The model cannot read the real phone number. Privacy is protected.
Analogy
A nickname system - instead of using your real name at school, you use a nickname. Teachers know you by nickname, not real name. PII redaction uses nicknames for private data.