Push delivery for corporate-action events (splits, oracle pauses, applied multipliers) — subscribe once and HoodGrow POSTs each event to your URL, so you never poll. Two ways to register: a credit-funded webhook (POST /api/agent/credits/webhook, billed per event) or a Builder webhook set on your self-serve key (PATCH /api/builder/key). Deliveries are signed x-hoodgrow-signature: sha256=<hex> (HMAC-SHA256). Note: this is HTTP push, not WebSockets — a persistent socket layer isn't offered.