As-told-to essay with Shane Mac, CEO of XMTP Labs (40), edited for length.
Mac built a personal “CFO” agent on Grok Bot around end of August 2026 with read-only access to personal checking and savings. Monthly reports covered balances, expenses, fraud signals, and cost advice, delivered only to a personal Grok group chat “My Personal Exec Team.”
On Thursday October 1, XMTP’s head of product DM’d Mac on Slack: a message looked like company financials but referenced personal spending on a barn build — the agent had posted a monthly audit to Slack channel “Exec-team” (company executives) instead of the similarly named personal agent group.
Grok’s investigation: the agent followed instructions but confused destinations because Mac had connected Slack to one agent while agents share underlying connections. Grok shipped a fix requiring explicit permission before agents move information across channels.
After the incident Mac disconnected Google, calendars, banking, Stripe, etc. He argues agents need stronger permission boundaries and clearer separation between personal and work identity surfaces.
Published: 2026-10-09T08:43:28.186Z