What is a semantic firewall for AI agents?

A semantic firewall is an execution governance layer that validates AI agent actions based on their meaning and intent — not just their syntax — blocking semantically dangerous operations even when they're syntactically valid.

Traditional firewalls filter network packets by IP, port, and protocol. They can't understand what an AI agent is trying to do — only where the traffic is going. A semantic firewall understands the action itself:

• Syntax check: Is the JSON valid? → Traditional validation handles this
• Schema check: Do the fields match the expected types? → Zod/JSON Schema handles this
• Semantic check: Is this action authorized? Does it violate business policy? Will it cause irreversible harm? → Only a semantic firewall handles this

Example: {"action": "db.write", "query": "UPDATE users SET role='admin' WHERE id=42"} passes every syntax and schema check. But a semantic firewall recognizes this is a privilege escalation and blocks it based on policy — not pattern matching.

Exogram is the semantic firewall for AI agents. It evaluates actions through 8 deterministic policy gates that understand the operational context, not just the data format. Code-based enforcement. 0.07ms latency. 0% error rate.