Struct NewEvent 

#[non_exhaustive]
pub struct NewEvent {
    pub correlation_id: CorrelationId,
    pub causation_id: Option<CausationId>,
    pub conversation_id: ConversationId,
    pub process_id: ProcessId,
    pub tenant_id: TenantId,
    pub workflow_id: WorkflowId,
    pub event_type: Box<str>,
    pub schema_version: u32,
    pub payload: Value,
}

A pending event ready to be appended to a stream.

The caller constructs a NewEvent for each domain event produced by a workflow command. Fields that the store assigns (event_id, sequence_number, timestamp, stream_id) are absent.

Idiomatic construction

Prefer CommandContext::new_event inside workflow handlers and transport adapters — it propagates all correlation IDs from the command context automatically:

// Inside a MessageAdapter or test:
let new_event = ctx.new_event(&SupplierChangeEvent::Initiated { .. })?;
store.append(&stream_id, ExpectedVersion::Any, &[new_event]).await?;

Use EventEnvelope::new_caused_event when building a follow-up event causally linked to a prior persisted event.

For test scaffolding that needs a NewEvent without a typed payload or context, use NewEvent::new. The #[non_exhaustive] attribute future-proofs callers against new optional fields being added without requiring a semver-breaking change.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

correlation_id: CorrelationId

Groups all events that originate from the same root command.

causation_id: Option<CausationId>

The event or command that directly caused this event, if any.

conversation_id: ConversationId

Links events belonging to the same business conversation.

process_id: ProcessId

Stable identifier for the MaKo process instance.

tenant_id: TenantId

Tenant that owns this event.

workflow_id: WorkflowId

Workflow definition that produced this event.

event_type: Box<str>

Stable, human-readable type discriminant (e.g. "SupplierChangeInitiated").

schema_version: u32

Schema version of the serialized payload.

payload: Value

The domain event payload, serialized as JSON.

Implementations

impl NewEvent

pub fn new( correlation_id: CorrelationId, causation_id: Option<CausationId>, conversation_id: ConversationId, process_id: ProcessId, tenant_id: TenantId, workflow_id: WorkflowId, event_type: impl Into<Box<str>>, schema_version: u32, payload: Value, ) -> Self

Construct a NewEvent from its constituent parts.

This is the escape hatch for callers that need full control over all fields (e.g. test scaffolding, migration tooling, storage-layer tests). In application code, prefer CommandContext::new_event which propagates correlation metadata automatically.

Trait Implementations

impl Clone for NewEvent

fn clone(&self) -> NewEvent

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for NewEvent

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.