# `Bourse.WS.AuthAck`
[🔗](https://github.com/ZenHive/bourse/blob/main/lib/bourse/ws/auth_ack.ex#L1)

Recognises which inbound frame is a venue's answer to an auth attempt.

The parallel of `Bourse.WS.SubscribeAck`, and it exists for the same reason:
on the asynchronous venues the auth reply arrives in the caller's mailbox
behind whatever else the socket is already delivering, so the waiter has to
tell "this is the auth outcome" apart from "this is a data frame".

The pattern modules' own `handle_auth_response/2` cannot answer that. Each
ends in a catch-all that reads an unrecognised frame as
`{:error, {:auth_failed, frame}}` — correct once you know the frame *is* the
auth reply, and a false rejection for any heartbeat or tick that happens to
land first. So recognition happens here and adjudication stays there:
`classify/2` only decides whether the frame belongs to the handshake.

# `classification`

```elixir
@type classification() :: :auth_response | :not_auth
```

# `classify`

```elixir
@spec classify(Bourse.WS.Auth.pattern(), map() | [map()]) :: classification()
```

Says whether `frame` is the venue's response to `pattern`'s auth attempt.

Returns `:auth_response` for a frame the pattern's classifier should judge,
and `:not_auth` for anything else — leave those in the mailbox.

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