CQRS & Domain Events

Command handlers

Every mutating operation is a Command struct carrying an IdempotencyKey (newtype Uuid v4), handled by a CommandHandler in application/commands/.

#![allow(unused)]
fn main() {
pub struct RunInvestigationCommand {
    pub idempotency_key: IdempotencyKey,
    pub objective: String,
    pub config: AgentConfig,
    pub auth: AuthContext,
}
}

Handlers check the idempotency_keys table before executing. Duplicate commands return the cached result without re-running.

Query handlers

Every read operation is a Query struct handled by a QueryHandler in application/queries/. Queries never mutate state.

Domain events

Every significant state transition emits a typed DomainEvent variant:

Events are immutable value types. Aggregate methods append them to a pending_events: Vec<DomainEvent>; the session store persists them via append_event.