Let's talk about making an ADE / meta-harness multi-provider.
Where do you draw the line between the provider and your own code?
Three approaches, followed by three tools in the space:
Orca: wrap the terminal. The providers' native TUIs run in embedded terminals. This is the easiest integration: any agent with a TUI can run in Orca, untouched. The downside is you can't make different providers look like one product.
AdaL: rebuild the harness. AdaL reimplements tool calling, compaction, the agent loop, etc., and uses the providers only for next-token prediction. Big upfront effort, but it means you can swap any provider underneath and get perfectly uniform UI and harness behavior.
Isomux: drive the SDKs. Isomux runs each provider's harness programmatically and renders one shared UI. It's a middle ground that leans on the provider's own harness for the hard parts while still owning the UI. Since each SDK is different, this approach has the most provider-specific code, requiring the most work per additional provider.
In all three cases, the meta-harness provides the agents with an API to perform actions at the meta-harness level, like driving the UI or orchestration.
Do you know of any other options?