# `AttestoPhoenix.BackChannelLogout`
[🔗](https://github.com/XukuLLC/attesto_phoenix/blob/v0.19.0/lib/attesto_phoenix/back_channel_logout.ex#L1)

The seam for delivering a Back-Channel Logout `logout_token` to a Relying
Party (OpenID Connect Back-Channel Logout 1.0 §2.5).

An implementation POSTs the token to the RP's `backchannel_logout_uri` as
`application/x-www-form-urlencoded` with a single `logout_token` parameter,
and reports whether the RP accepted it. Delivery is best-effort by design:
the end-session endpoint logs failures but never blocks the user's logout on
an unreachable RP. The default implementation is
`AttestoPhoenix.BackChannelLogout.Req`; a host overrides it with
`logout: [http_client: MyDeliverer]`.

# `post`

```elixir
@callback post(backchannel_logout_uri :: String.t(), logout_token :: String.t()) ::
  :ok | {:error, term()}
```

POST `logout_token` to `backchannel_logout_uri`. Returns `:ok` when the RP
responded with a 2xx, `{:error, reason}` otherwise.

---

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