Does Sume offer Haiku 5.5, GLM 5.3 Flash or Mistral Large 4?

As of 2026-10-08, Sume's agent model catalog in the repository has enabled rows for Claude Haiku 5.5 and GLM 5.3 Flash. It has no row for Mistral Large 4, Cloudflare Clef, Amazon Strands Decider 2B, or a model named GLM 5.3 Fast. Separately, the public Agent Completions model field accepts only sume-agent.

The answer, model by model

I checked the catalog file that defines every model id the product can name, and compared each against the vendor's own page. A catalog row means the product can name the model in its Agents model picker; which environment shows it depends on gates, so confirm in your own workspace.

Two different questions

There are two surfaces, and people mix them. The Agents chat UI and Scheduled automations pick a model. The developer API for Agent Completions does not: its model field accepts only sume-agent, and omitting it gives you the same agent. A value other than sume-agent returns 400 invalid_request.

The Scheduled docs say a schedule has "a model" next to its cron expression and spend cap, and that you choose it when you write the instructions in the dashboard.

What I dropped

The brief for this week named GLM 5.3 Fast. I found no Sume catalog row by that name, and the only vendor page I could read describes GLM-5.3-Flash and a FlashX variant. So this post makes no claim about a Fast model. I also make no claim about prices of GLM or Mistral, because I did not read a vendor price page for them.

How to use this

The points that matter here, in the order you will hit them:

• For the developer API, send sume-agent or omit the field.
• For Agents chat and schedules, open the picker and use what it shows.
• Run decision models such as Clef or Strands Decider in your own service, before you call Sume.
• Re-check after a release; a name in the news is not a name in a catalog.

How the catalog was checked

The catalog declares each model id once, with a label, an enabled flag, a gate that says which environment lists it, and a route. Claude Haiku 5.5 and GLM 5.3 Flash have enabled: true and an OpenRouter gate. The older Haiku 4.5 row is disabled and points to Haiku 5.5 as its successor, so stored threads that used it move forward. No row exists for the other names in the table. I did not verify pricing in Sume for any of these models, so this post gives vendor prices only where a vendor page was read.