Knock provides customer engagement infrastructure that helps businesses manage product, marketing, and transactional messaging from one platform. Its tools let teams bring together real-time data from products, warehouses, customer data platforms, reverse ETL systems, and webhooks, then use user attributes, events, and actions to create audiences and trigger relevant communications.

The platform supports messaging across email, SMS, push notifications, chat, and in-app experiences. Teams can design automated workflows and broadcasts, personalize content and targeting, and build experiences such as paywalls, dialogs, and in-app notifications using their own components. Knock also offers email generation, preference centers, and send-window controls to help tailor delivery to user needs.

Built for developers and cross-functional teams, Knock provides APIs, SDKs for major programming languages, a CLI, version control, deployment validation, observability, and integrations with AI coding tools. These capabilities help teams build, test, debug, and manage messaging without operating the underlying infrastructure themselves. Knock highlights enterprise-oriented reliability, security and compliance credentials, and scalable delivery, while giving non-engineers tools to collaborate on messaging content and targeting.