The Guardrail Catalog: Runtime Checks, Mapped Per Cloud

Guardrails are runtime checks that live outside the model — input filters, output classifiers, tool-call validators, PII redaction, grounding checks. Build them as a reusable catalog (risk → check → placement → cost), map each entry onto Bedrock, Foundry and Gemini Agent Platform, and learn why a catalog without containment is theatre.

Content current as of 2026-09.

Lessons

1. What a guardrail is — and what it can never be
2. The catalog pattern: eight entries you can reuse
3. Per-cloud mapping: Bedrock, Foundry, Gemini Agent Platform
4. Placement in the loop — and how catalogs fail
5. Worked fix: sanitising output before it renders