Default Deny
Default deny is an access control principle where all actions are denied unless explicitly permitted by policy—as opposed to default allow, where actions proceed unless explicitly blocked.
Why this matters for AI agents
Default deny is the only sustainable posture for autonomous agents. Agents discover tools at runtime and may encounter tools that were not anticipated when policy was written. Default deny ensures unanticipated calls are blocked.
How AgntID relates
AgntID operates on a default deny model—if no policy explicitly permits a tool call, it is denied and a structured denial is returned. Ungoverned tools cannot be invoked by accident.
The static IAM gap
Many cloud IAM configurations have implicit allows through broad role assignments. Default deny requires explicit, narrow grants—a discipline that is hard to maintain with static role-based access control.
Related phrases
Frequently asked questions
What is default deny for AI agent access control?
Default deny is an access control principle where all agent tool calls are denied unless explicitly permitted by policy, as opposed to default allow, where calls proceed unless explicitly blocked.
Why is default deny essential for autonomous agents?
Agents discover tools at runtime and may encounter tools that were never anticipated when policy was written. Default deny ensures unanticipated calls are blocked rather than allowed.
How does AgntID enforce default deny?
AgntID operates on a default deny model. If no policy explicitly permits a tool call, it is denied and a structured denial is returned to the agent.
Secure every agent tool call at execution time.
AgntID gives infrastructure teams scoped, ephemeral access control for AI agents without replacing IAM, MCP servers, tools, or agent frameworks.