Last updated: September 2026
What Knock Actually Is
Knock is notifications infrastructure for developers. Building product notifications properly, across email, in-app feeds, push, SMS, and Slack, with user preferences, batching, and templates, is a surprising amount of work. Knock is a single API that handles all of it, so engineering teams can ship a real notification system without building and maintaining one from scratch.
You define notification workflows once and Knock routes each message to the right channel based on your logic and each user's preferences.
Try Knock Get started →The Feature That Sets It Apart: Cross-Channel Workflows
The hard part of notifications is not sending one email, it is orchestrating: notify in-app first, fall back to email if unread, respect quiet hours, batch a flurry of events into one digest. Knock models these as workflows you configure rather than code, so behavior that would take weeks to build and debug becomes a setting. That orchestration layer is the reason teams adopt it instead of rolling their own.
What Else It Does
Preference Management
It gives you a preference center so users control what they get and where, which keeps you compliant and cuts unsubscribes without custom work.
In-App Feed Components
Prebuilt components let you drop an in-app notification feed into your product quickly, rather than building the UI and its backend.
Templates and Observability
Non-engineers can edit notification templates, and logs let you see exactly what was sent, to whom, and why, so debugging deliverability is straightforward.
Pricing
Knock has a free tier for developers to build and test, with paid plans that scale message volume and team features. You can integrate and prototype before paying anything.
Who It Is For
Knock fits product and engineering teams building software that needs to notify users across channels. If your app sends a single transactional email, a basic email API is enough. If notifications are a real surface in your product, Knock saves you from building and owning that infrastructure.
What channels does Knock support?
Email, in-app feeds, push, SMS, and chat tools like Slack, all orchestrated through one API and workflow engine.
Does Knock handle user preferences?
Yes. It includes a preference center so users control which notifications they receive and on which channels.
Is Knock free to start?
Yes. It has a free tier for developers to build and test, with paid plans that scale volume and team features.
