I spent at least an hour trying to get OpenCode to use a local model and then found a graveyard of PRs begging for Ollama support or even the ability to simply add an OpenAI endpoint in the GUI. I guess the maintainers simply don't care. Tried adding it to the backend config and it kept overwriting/deleting my config. Got frustrated and deleted it. Sorry but not sorry, I shouldn't need another cloud subscription to use your app.
Claude code you can sort of get to work with a bunch of hacks, but it involves setting up a proxy and also isn't supported natively and the tool calling is somewhat messed up.
Warp seemed promising, until I found out the founders would rather alienate their core demographic despite ~900 votes on the GH issue to allow local models https://github.com/warpdotdev/Warp/issues/4339. So I deleted their crappy app, even Cursor provides some basic support for an OpenAI endpoint.