# `Chronicle.EventSequences.EventForEventSourceId`
[🔗](https://github.com/Cratis/Chronicle.Elixir/blob/main/lib/chronicle/event_sequences/event_for_event_source_id.ex#L4)

Represents an event buffered for a specific event source within an event sequence.

Omitted, `nil`, or empty routing values defer to the kernel's source type,
stream type, and stream id defaults. Explicit nonempty routing is preserved.
`occurred: nil` leaves timestamp assignment to the kernel; an explicit
`DateTime` is preserved, including when the event is buffered in a transaction.

Concurrency scopes are independent filters, not routing defaults. A missing
scope sends no explicit constraint for this source; a scope, including `none()`,
is sent unchanged. For repeated sources, the first declared scope wins.

`event_source` (a `Chronicle.EventSources.EventSource` module or name) and
`event_stream` route this event through a registered definition, overriding any
batch-level `:event_source`/`:event_stream` option. An explicit `concurrency_scope`
always wins over the definition's concurrency dimensions. `routing` is resolved
internally and not meant to be set.

Rich batches carry routing, tags, subject, and occurred time per event. Their
causation and identity remain batch-level: explicit batch causation wins,
and the first resolved entry identity wins over the batch identity option.
Transaction commits use the first entry's causation and the same resolved-entry
identity precedence.

# `t`

```elixir
@type t() :: %Chronicle.EventSequences.EventForEventSourceId{
  causation: [Chronicle.Auditing.CausationEntry.t()],
  concurrency_scope: Chronicle.Events.ConcurrencyScope.t() | keyword() | nil,
  event: struct(),
  event_source: module() | String.t() | nil,
  event_source_id: String.t(),
  event_source_type: String.t() | nil,
  event_stream: String.t() | nil,
  event_stream_id: String.t() | nil,
  event_stream_type: String.t() | nil,
  identity: Chronicle.Identity.t() | nil,
  occurred: DateTime.t() | nil,
  prepared: %{event_type: struct(), content: String.t()} | nil,
  routing: Chronicle.EventSources.Routing.t() | nil,
  subject: String.t() | nil,
  tags: [String.t()] | nil
}
```

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*Consult [api-reference.md](api-reference.md) for complete listing*