Problem
When a user is not signed in and starts a Claude session, the model picker defaults to "Auto". The Auto model resolution doesn't work with Claude sessions — it results in a "Language model unavailable" error.
Expected Behavior
When no models are available (because the user isn't signed in), the Claude session should either:
- Prompt the user to sign in before starting the session
- Show a clear error that authentication is required, not a generic "Language model unavailable"
The "Auto" model should not be selectable for Claude sessions if it can't resolve to a valid Claude model.
Steps to Reproduce
- Launch VS Code Insiders with a fresh
--user-data-dir (no auth)
- Open the Chat panel
- Switch session target to Claude
- Send any message
- Error: "Language model unavailable"
The model picker shows "Auto" which gets picked up but can't resolve to a Claude model since the user has no access.
Context
Discovered during launch skill testing (agent-browser automation). The folder fallback fix (PR microsoft/vscode-copilot-chat#4212) resolved the "No folder available" error, which unmasked this underlying model resolution issue.
Problem
When a user is not signed in and starts a Claude session, the model picker defaults to "Auto". The Auto model resolution doesn't work with Claude sessions — it results in a "Language model unavailable" error.
Expected Behavior
When no models are available (because the user isn't signed in), the Claude session should either:
The "Auto" model should not be selectable for Claude sessions if it can't resolve to a valid Claude model.
Steps to Reproduce
--user-data-dir(no auth)The model picker shows "Auto" which gets picked up but can't resolve to a Claude model since the user has no access.
Context
Discovered during launch skill testing (agent-browser automation). The folder fallback fix (PR microsoft/vscode-copilot-chat#4212) resolved the "No folder available" error, which unmasked this underlying model resolution issue.