Fabric SDK Requirements

[salamichobani]

Overview

Fabric plans to move onto the Copilot SDK but is waiting on being able to list available models without spinning up the whole agent harness.

The issue is to solve this for harness customers that also want primitives. They use the harness and want lightweight primitives like model listing. We plan it to Invest in the lightweight primitives and work out how the platform scales as this route grows (the auth / no-integration-ID problem).

• Non-harness customers (OpenCode, Zed) are a separate problem. Needs discovery to understand how big this base actually is and what they need. If it's just OpenCode/Zed, maybe we keep today's solution; if it's bigger, we figure out the best route (will be in another issue)

From the CAPI + SDK strategy chat, we agreed the SDK is the front door and we'd build lightweight primitives (model discovery, inference) that don't need the full harness. Fabric is on direct CAPI today as an interim thing, and we'd rather they converge on the SDK than keep growing custom CAPI integrations.

Documentation

Document going over the SDK/CAPI meeting + outstanding issues and takeaways here

Next steps

• Nail down Fabric's actual requirements (must-have vs. nice-to-have).