GateKeeper: Vendor Risk Approval

GateKeeper is a multi-agent vendor onboarding and procurement risk approval system for regulated enterprise workflows. Instead of using a single chatbot, GateKeeper coordinates five specialized agents through Band: an Orchestrator, Researcher, Risk Assessor, Approver, and Reporter. When a new vendor is submitted, the Orchestrator starts the case, the Researcher prepares structured vendor context, the Risk Assessor screens sanctions and scores financial, security, and compliance risk, the Approver applies deterministic procurement policy, and the Reporter generates an audit-ready final report. Band is used as the coordination and audit layer. Agents collaborate through @mention routing, structured JSON handoffs, tool-result events, memory updates, and a visible coordination trail. GateKeeper supports three decision paths: Low-Risk Fast Path, Human Review Escalation Path, and Compliance Rejection Path. It also includes dynamic behavior such as second-pass review for medium-risk vendors and compliance escalation for sanctions hits. The result is a transparent approval workflow that reduces manual coordination, improves policy consistency, supports human-in-the-loop review, and creates a live audit trail for high-stakes procurement decisions.