# `Capstan.Transaction`
[🔗](https://github.com/baselabs/capstan/blob/v1.3.1/lib/capstan/transaction.ex#L1)

A decoded, committed transaction delivered to a `Sink`.

`changes` is typed `Enumerable.t()`, **not** a list. C1 delivers a list, but the
type is the day-one contract: C3's spill/batch work must be able to switch a
transaction's `changes` to a lazy, single-pass, disk-backed enumerable — as
replicant does — without silently breaking a sink. A sink MUST NOT call
`length/1` (or anything else requiring more than one pass) on `changes`; a
single-pass enumerable would raise or return a wrong count on a second pass, and
a `length/1` habit that happens to pass every capstan test today would silently
consume a single-pass reader later. Enumerate once, streaming (`Enum.reduce/3`,
`Enum.each/2`, `for`, or `Stream` pipelines that consume the enumerable exactly
once).

`position` is the processed GTID set INCLUDING this transaction — see
`Capstan.Position`. `gtid` is this transaction's own identity, `"uuid:gno"`.

# `t`

```elixir
@type t() :: %Capstan.Transaction{
  changes: Enumerable.t(),
  commit_ts: DateTime.t(),
  gtid: String.t(),
  position: Capstan.Position.t()
}
```

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