mod subscriber

module subscriber

Global and scope-local event subscriber registration helpers.

Functions

fn deregister_subscriber(name: &str) -> Result<bool>

Deregister a global lifecycle event subscriber.

This removes the named subscriber from the process-wide registry.

Parameters

• name: Global subscriber name to remove.

Returns

A Result containing true when a subscriber was removed and false when the name was not registered.

Errors

Returns an error when the global registry lock cannot be acquired safely.

Notes

Deregistration affects only future event delivery.

fn register_subscriber(name: &str, callback: EventSubscriberFn) -> Result<()>

Register a global lifecycle event subscriber.

The subscriber is added to the process-wide registry and receives every emitted scope, tool, LLM, and mark event until it is deregistered.

Parameters

• name: Unique subscriber name in the global registry.

• callback: Subscriber callback invoked for each emitted event.

Returns

A Result that is Ok(()) when the subscriber was registered.

Errors

Returns FlowError::AlreadyExists when another global subscriber is already registered under the same name.

Notes

Global subscribers remain active across scopes until explicitly removed.

fn scope_deregister_subscriber(scope_uuid: &uuid::Uuid, name: &str) -> Result<bool>

Deregister a scope-local lifecycle event subscriber.

This removes the named subscriber from the registry attached to a specific active scope.

Parameters

• scope_uuid: UUID of the owning scope.

• name: Scope-local subscriber name to remove.

Returns

A Result containing true when a subscriber was removed and false when the name was not registered on that scope.

Errors

Returns FlowError::NotFound when the scope does not exist on the active stack.

Notes

Deregistration affects only future event delivery for that scope.

fn scope_register_subscriber(scope_uuid: &uuid::Uuid, name: &str, callback: EventSubscriberFn) -> Result<()>

Register a scope-local lifecycle event subscriber.

The subscriber remains active only while the target scope is still present on the active scope stack.

Parameters

• scope_uuid: UUID of the owning scope.

• name: Unique subscriber name within the owning scope.

• callback: Subscriber callback invoked for events emitted under that scope hierarchy.

Returns

A Result that is Ok(()) when the subscriber was registered.

Errors

Returns FlowError::NotFound when the scope does not exist on the active stack and FlowError::AlreadyExists when the scope already owns a subscriber with the same name.

Notes

Scope-local subscribers are removed automatically when the owning scope is popped.