# `Ankusa.Sink.Description`
[🔗](https://github.com/jamescarr/ankusa/blob/ankusa-v0.7.0/packages/ankusa/lib/ankusa/sink/description.ex#L1)

Where a sink delivers, as `c:Ankusa.Sink.describe/2` reports it: the broker,
the channel address, and the protocol bindings a consumer needs.

`Ankusa.AsyncApi` folds the ones that publish the envelope (`:payload` is
`:message`) into the AsyncAPI document the admin API serves.

  * `:protocol` / `:host` — the broker (`"kafka"`, `"amqp"`, `"nats"`, `"redis"`, `"sqs"`
    and `"host:port"`, comma-joined when the sink has several). Never carries
    userinfo: a description is served to anyone who can reach the admin port.
    `:host` is `nil` when a function computes the destination per hook.
  * `:pathname` — the broker's path (a RabbitMQ vhost as `"/prod"`, a Redis
    database as `"/2"`), or `nil`.
  * `:address` — the topic, routing key, subject, or channel; `nil` when a
    configured function computes it per hook.
  * `:ankusa_headers` — true when each message also carries the `ankusa_*` /
    `content_type` application headers (Kafka and NATS headers, SQS and Pub/Sub
    message attributes); the AsyncAPI document then references
    `SinkMessageHeadersV1` for the message.
  * `:channel_bindings` / `:message_bindings` — AsyncAPI binding objects keyed
    by protocol (`%{"kafka" => %{...}}`), `%{}` when the protocol defines none.
  * `:payload` — what the sink sends: `:message` (the `Ankusa.Sink.Message`
    envelope, which the AsyncAPI document describes) or `:body` (the provider's
    raw bytes, as `Ankusa.Sink.Http` does, which it does not).
  * `:computed` — the options a function computes per hook (`:url`, `:headers`
    and `:secret` of `Ankusa.Sink.Http`), so this description holds for the
    sink's configuration but not for any one hook; `[]` when every option is
    static.

# `t`

```elixir
@type t() :: %Ankusa.Sink.Description{
  address: String.t() | nil,
  ankusa_headers: boolean(),
  channel_bindings: map(),
  computed: [atom()],
  host: String.t() | nil,
  message_bindings: map(),
  pathname: String.t() | nil,
  payload: :message | :body,
  protocol: String.t()
}
```

---

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