The agency problem

An agency manages many accounts for many clients, often with several people touching the same account. The risk is not that the AI spends too much — it cannot spend at all without approval. The risk is losing track of who approved what across dozens of accounts, and a single account quietly absorbing more change than it should.

SpendSignoff addresses both with the same primitives it uses for a solo operator, applied per account: a spend envelope on each, and a signed record of each approval.

What scales cleanly

• Each linked account carries its own rolling 24h spend envelope, so one client account cannot drain into another and no single account runs away.
• Every approval is a KMS-signed, append-only audit entry naming the approver — across all client accounts, you can answer "who pushed this and when" without guessing.
• Reads are ungated, so junior operators can review what the operator would draft on any account before anyone has approve rights.
• One-click rollback is per-change, so reverting a client mistake does not mean rebuilding a campaign by hand.

A workable agency setup

Keep the spend decision with named people and let the operator do the reading and drafting across the book.