Analytics events are stamped with the account that produced them and filtered by it

What

Claude Code sends its own usage analytics to Anthropic. Each event is now tied to the principal, meaning the signed-in identity, that produced it:

• Both ways of recording an event now attach a value worked out from the event name, as principalStamp (principal_stamp when sent). Events queued before analytics has started keep their stamp.
• When sending, events stamped with a different principal from the current one are dropped. Events are also dropped by HIPAA-style checks, a set of safety events was added, and some internal events are removed when the data is cleaned up.
• The stamp is passed along with every event that is sent.
• In some cases the identity sent with events is built only from the environment variables CLAUDE_CODE_ACCOUNT_UUID, CLAUDE_CODE_ORGANIZATION_UUID, CLAUDE_CODE_SUBSCRIPTION_TYPE and CLAUDE_CODE_RATE_LIMIT_TIER, instead of the stored account. The device ID falls back to those account and organization IDs.

Why

If you switch accounts, events recorded under one account are no longer sent as if they came from another, so analytics stay tied to the account that produced them.