Yes, as others replied, just plug in an agent with a model config pointed at OpenRouter. I do this all the time with OpenCode and Pi. Give me a reply if I can help you on this.
OpenCode fixed it for me, I just asked it to set up itself as an ACP server for Jetbrains Air. Running with that now.
Hadn't used ACP yet.
It supports ACP, so you can use it with any ACP speaking harness including many that would work with local agents
Maybe I'm misunderstanding, but isn't a sizeable part of the article about how Air can be used with any agent (section "The future is multi-vendor")