[FEATURE] Support multiple authenticated accounts / per-project account switching for subscription users

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Problem:

Claude Code only supports a single authenticated account via OAuth. Developers working across multiple organisations (e.g. personal + work accounts) must constantly log out and log back in when switching projects.
Unlike API key users who can set ANTHROPIC_API_KEY per project, subscription users have no equivalent workflow.

Example

I maintain two projects:

• Personal project (personal subscription)
• Work project (Team subscription)

Switching between them requires re-authentication. Worse, OAuth silently uses the active browser session, making it easy to bill the wrong account without noticing.

Why this matters

This isn’t just inconvenient. it creates real risk:

• Incorrect billing between personal/work accounts
• Potential breaches of employment or client agreements
• Confidential data tied to the wrong organisation
• No visibility when OAuth silently selects the wrong account

Proposed Solution

I'd like to be able to do one of the following:

• Named account profiles:

run claude auth add --profile personal , claude auth add --profile work, then a per-project setting
(.claude/settings.json) that specifies which profile to use. Zero friction once set up.

• Per-project auth override — allow .claude/settings.json or .claude/settings.local.json to specify an account/org, prompting login if that account isn't already cached.

1. Allow claude auth switch at minimum, a fast account-switcher that doesn't require a full browser OAuth round-trip each time.

Anyhow - the used account should be accessible to the user with request like claude auth --current_user

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

CLI commands and flags

Use Case Example

I maintain two projects:

• Personal-project (personal subscription)
• Work-project (Team subscription)

I'm logging in the Personal account and working in that personal-project.
I switch the work-project on a different window/terminal and logging in to my claude Work account.
When switching back to the Personal-account terminal, the account silently switches to the work-account
Critical issue is the silent switch
The current possible solution is a logout/login in the personal account, and another login/logout when switching back to work on the Work project. That's a lot of friction.

Additional Context

_No response_