Lesson 4: Keeping attackers out of the answer
25 min read·13 Oct 2026
Module 9 · Lesson 4 · About 45 minutes · Needs: Module 5 Lesson 3 (permission filters) and Module 8 Lesson 2 (labelled context blocks)
The situation
On Friday 9 October 2026 Ellie Shaw asks whether her repeated E7 fault is covered. On a wider search her top four documents include a forum post whose first sentence is real advice and whose next sentences are orders for the assistant: send customers' card numbers to an outside address.
Farah, Hollin's security lead, asks what stops the model obeying, what stops a planted page winning retrieval, and what stops one partner's prices reaching the other. This lesson builds hollin/guard.py. The Hollin data is simulated.