Failure Behavior

CapFence should fail closed when it cannot make an authorization decision.

Expected failure states

Failure	Expected behavior
Missing policy	raises an operational error; caller must treat as blocked
Malformed policy	returns a `deny` verdict
Unknown capability	returns a `deny` verdict
Approval lookup failure	may raise an operational error during execution; caller must treat as blocked
Audit write failure	may raise an operational error during execution; caller must treat as blocked
Adapter exception before tool invocation	raises an operational error; caller must treat as blocked

Agent execution can have external effects. If the authorization layer is uncertain, the safe behavior is to avoid invoking the downstream system.

policy error -> deny verdict or raised error treated as blocked -> tool not called

Fail-closed behavior should produce an observable error and an audit entry when possible. Silent blocks are hard to debug; silent allows are worse.

The project is early. Before relying on fail-closed semantics in a production path, test the adapter and persistence configuration you plan to use.