Show which provider instance is active in the composer and the model picker

[genesiscz]

Note

Written with Claude Opus 5.5 on behalf of Martin.

Follow-up to #17506, which was closed with a request to bring it to Ideas.

The problem

I run one Claude Code instance per account (a small launcher picks the account from an environment variable), so the provider list has many instances of the same driver:

For subagents this already works well. The agents panel hover card names the instance:

The main thread does not. Two places are missing the same fact:

1. The composer model button does not say which instance runs the thread

It shows the model, the effort and a two-letter badge. Hovering it shows nothing, so with several Claude instances "Opus 5.5 Medium" could be any of them.

Proposal: when two or more instances share a driver, the button's tooltip and accessible name add the instance name, for example Claude Opus 5.5 · Medium · Claude Code (work-b) · ⇧⌘M. With one instance per driver nothing changes. I know #28076 removed the composer tooltip on purpose, which is why this proposal keeps it off in the normal case and adds it back only when the name is ambiguous.

2. The picker rail has no "active" marker

The rail highlights only the instance being browsed. When favorites exist, the picker opens on Favorites, so the active instance and its check mark are out of view, and I click through every Claude instance to find the one the thread runs on:

Proposal: a small status dot on the active instance's rail icon, separate from the browsing highlight (the blue bar below), plus "· Active" in that icon's tooltip and aria-current on the button.

Mobile

Mobile has its own model picker, so the same two gaps need a decision there. I would start with web and desktop (they share the composer) and follow up on mobile if the direction is accepted.

Related: telling the instances apart

The badge text is derived from the display name (first letters of the first two words), so "Claude Work" and "Claude Work 2" both read "CW", and my instances all read "CC". Custom icons and badge labels per instance are already proposed in #7366 (point 1) and implemented in #15185 and #26236, so this discussion does not repeat that. It only asks for showing which instance is active.

Implementation

I have a small implementation of 1 and 2 (web and desktop, 4 files, one test assertion added to the existing picker browser test). Before and after, with placeholder account names:

	Before	After
Hover on the composer model button
Picker open on Favorites, hovering the active instance

I will open it as a draft PR linked here. Is this direction and scope OK?