A credential broker sits between an AI agent and the accounts or services it needs to act on, evaluating each access request in context and issuing just-in-time, often short-lived access rather than handing over a standing password or API key. The goal is to let an agent complete real tasks — logging into an account, making a purchase, filling a form — while keeping the raw secret out of the agent's own process, so a prompt-injected or misbehaving agent cannot exfiltrate it. 1Password's Unified Access platform and Instinct's 2026 integration with it are examples of this pattern applied to personal AI agents.