# AgentBlackBox – a policy gate and tamper-evident audit log for AI agents > Source: > Published: 2026-10-18 07:25:01+00:00 AgentBlackBox records what an AI agent saw, decided, requested, changed, blocked, and executed — and who approved it — into a tamper-evident, cryptographically chained audit trail you can prove to a customer, auditor, or regulator. AgentBlackBox sits between your AI agents and the systems they touch and records a complete, ordered, tamper-evident log of their behavior and the human approvals around it. Each work unit (a task an agent is handling) gets a timeline of events, a policy gate, optional human sign-off, and a one-click audit report. Autonomous agents now read inboxes, move money, change records, and message customers. When something goes wrong — or a customer, auditor, or regulator asks “what exactly did the AI do, and who approved it?” — you need a provable answer. A tamper-evident hash chain makes the record trustworthy: nothing can be quietly edited after the fact without detection. Every event is SHA-256 hashed and linked to the previous one (prevHash → eventHash) from a GENESIS root. Any edit, insert, or delete breaks the chain and is instantly detectable. Records what an agent observed, decided, requested, executed, blocked, or errored on — in order, with payloads. High-risk actions gate on a human decision. Approvals and denials are themselves recorded as chained events. Simulate any proposed action and get ALLOW, REQUIRE_APPROVAL, or BLOCK with the matched rules and a recommendation. One-click, investor-ready audit report per work unit with executive summary, full event log, Print / Save as PDF, and JSON export. External AI agents POST events to /api/events with an API key. Mock connectors (Gmail, Slack, Drive, Browser) show the future surface. Walk the full loop in a couple of minutes: Start a new tamper-evident timeline for a task an agent is handling. Run a proposed action through the policy engine to see ALLOW / REQUIRE_APPROVAL / BLOCK. Add an observation, decision, or tool call — it chains onto the timeline. Decide on a pending high-risk request; the decision is recorded as an event. See the executive summary, full event log, and hash-chain status. External OAuth integrations, billing, and banking are intentionally mocked in this MVP until credentials are configured. Download the signed-style JSON record or save a clean PDF for an investor or auditor.