# `Parlora.Channels.Telnyx.Endpoint`
[🔗](https://github.com/hfiguera/parlora/blob/v0.1.0/lib/parlora/channels/telnyx/endpoint.ex#L1)

Mountable signed Telnyx v2 webhook admission. This module starts no listener.

Mount `webhook/2` before a JSON body parser. Supply `:public_key` and a bounded
`:on_event` admission callback. The callback must atomically authorize and
deduplicate the verified event and enqueue admitted work. It returns one of
these values; return `:ok` for an already admitted duplicate too:

| Callback return | HTTP status | Response body |
| --- | --- | --- |
| `:ok` | 200 | `"OK"` |
| `{:error, :backpressure}` | 503 | `"Unavailable"` |
| `{:error, reason}` for any other reason | 403 | `"Forbidden"` |

The 503 response allows Telnyx to retry delivery. Do not perform REST commands
in the admission callback; run them in supervised workers.

Signature freshness does not replace event/call deduplication. The host retains
terminal call identities and enforces listener, mailbox and concurrency bounds.
Neither caller ID nor possession of an event ID authenticates an application user.

# `upgrade`

Admit a media upgrade using Telnyx's separate authentication header.

The host's `:authorize` callback receives `(conn, token)` and must atomically
compare/consume an expiring, call-bound token before returning
`{:ok, socket_options}`. Use constant-time comparison. The API key is never a
stream credential. Never accept an unverified token echoed in a connected frame.

# `webhook`

Verify the exact bounded request body before decoding or invoking application code.

---

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