Is there an ElevenLabs or OpenAI model in Sume's TTS Router? No

No. The TTS Router on Sume currently lists Cartesia Sonic only: sonic-3.6, sonic-3.5, sonic-3, sonic-latest and sonic-preview. The router docs state that v1 does not include Eleven, OpenAI or other TTS families, and that later vendors would be new catalog rows rather than a new surface.

What the router is

The router is a pass-through surface: you send a required model id from the catalog and Sume bills the listed per-character rate with its margin. TTS 1.0 is the managed product with no model field; if you send model or model_id there, you get a 400. On the router, an unknown model returns a 400 that includes a catalog_url pointing at /v1/tts-router/models.

How to check before you build

Call GET /v1/tts-router/models and read the ids. Do not hard-code a list from a blog post, including this one. If your workflow depends on a specific vendor's voice, the catalog is the only reliable answer on a given day. A cheap way to stay informed is to poll the catalog and alert when an id appears.

Why a narrow catalog can be fine

A short catalog means fewer decisions. Every id has the same per-character price, so you can compare them on quality alone, and TTS 1.0 removes even that choice by always using sonic-3.6. The cost of a narrow catalog is that you cannot pick a different vendor's voice quality, language coverage or emotive range, so decide whether that matters for your project before you build on it.

What to do if you need another vendor

Use that vendor's own API for the voice, then bring the audio into Sume for the parts it does cover: captions, trimming and timeline assembly. Keep the vendor's price and terms in your own records, since Sume's rate card applies only to the models in its catalog.