Run: Use multiple accounts per host, including GitHub.com #9005

Goal

Use multiple accounts on the same GitHub host concurrently, including separate personal and work accounts on GitHub.com, with explicit repository-to-account selection.

This is the Run phase, building on host-aware connections in Walk (#9004). Crawl (#9003 / #8996) provides basic multi-Enterprise configuration and account switching; Walk adds simultaneous hosts. Neither phase provides simultaneous accounts on one host.

User experience

In one window, a user should be able to work on repository A with one account and repository B with another account on the same host, without repeatedly changing a provider-wide preference. The selected account and its permissions should be clear, and changing one binding should not silently switch unrelated repositories.

Scope

• Identify connections by provider, issuer/deployment, and account. Do not rely on account labels or native IDs being globally unique.
• Define an explicit repository-to-account binding and account-picker experience. Do not infer authentication identity from Git commit authorship or a username embedded in a remote URL.
• Decide where bindings persist, how workspace preferences interact with user preferences, and what happens when a binding is absent, inaccessible, signed out, or removed.
• Request and validate the intended account and issuer for every repository-bound operation, including reauthentication and scope upgrades. Never silently retry an operation with another account just because it has access.
• Partition permission-sensitive repository metadata, user caches, reviews/comments, and notifications by connection identity, including when the same repository is accessible to several accounts.
• Define account selection or aggregation for hostless tools, notifications, clone/search, and agent entry points.
• Keep sign-in, consent, switching, and removal explicit while reusing native authentication/account UX where the platform supports it.

Design prerequisite

Verify which VS Code authentication and account-preference APIs can express the required bindings before committing to the UX. Coordinate with upstream structured-account identity work rather than encoding identities into display labels or creating a competing preference store without a clear need.

Acceptance

• Two GitHub.com accounts can operate concurrently on different repositories in one window.
• Two accounts on the same Enterprise instance can operate concurrently, including different permissions and scope sets.
• Switching/signing out/re-authenticating one binding does not change another account's repositories or cached state.
• Ambiguous or missing bindings produce an actionable choice/error, not an unintended account fallback.
• Regression coverage proves credentials, comments, notifications, and permission-sensitive data do not cross account boundaries, with real-account verification across supported environments.

Related

• Detect if the user has multiple accounts, and if the one configured for the workspace might be the wrong one #7745 tracks detecting that the currently selected account may be wrong; that is a related, narrower UX problem rather than simultaneous account support.
• Walk/Run design outline.