Do they have their own cli agents or just the api inference services?

Some do, I know of kimi code https://www.kimi.com/code

I don't think they do but you can always use OpenCode or Pi Agent.

very easy to configure claude code to route to GLM as well.

Moonshot AI has Kimi Code and their $20 per month plan had a lot more than Anthropic's (before 4.6 and the other changes to eat up your limit faster).