Knock is a notification infrastructure API for developers. See how Knock's workflows, pricing tiers, and features compare to Courier, Novu, and OneSignal.
Knock is a notification infrastructure platform founded in 2021 by former Frame.io product and engineering leaders Sam Seely and Chris Bell. Rather than a marketing campaign tool, Knock is a developer-first API and workflow engine that sits between an application's backend and its delivery providers, handling the plumbing of sending reliable, multi-channel notifications.
Teams define reusable notification workflows in a visual builder or in code, covering email, SMS, push, in-app messages, chat, and Slack, with conditional logic, batching, and digesting built in. Knock is backed by Craft Ventures and Afore Capital and is used in production by companies including Vercel, Webflow, and Amplitude.
Knock's core is the workflow engine: multi-step, multi-channel messaging journeys with per-recipient preference checks, send-window controls, and an AI workflow builder that can draft a workflow from a single prompt. Data can be synced in from warehouses, CDPs, or webhooks to personalize templates dynamically.
For developers, Knock offers SDKs in eight languages, a CLI compatible with AI coding assistants, environment-based version control with rollback, and built-in observability for tracing individual message deliveries. Prebuilt frontend components add in-app notification feeds, inboxes, and targeted guides like banners and modals.
Knock uses a three-tier, usage-metered pricing model. The free Developer plan includes 10,000 messages and 500 guide active users per month with unlimited workflows and channels. The Starter plan costs 250 dollars per month for 50,000 messages and adds branding removal and email previews.
Enterprise pricing is custom and volume-based, unlocking translation support, HIPAA BAAs, SAML SSO, and priority support. Overage charges across all tiers are billed in arrears on the following month's invoice.
Knock is used by engineering teams to build and manage product notifications, such as transactional emails, push alerts, SMS, in-app messages, and Slack notifications, through a single API and workflow builder instead of building delivery infrastructure from scratch.
Yes, Knock has a free Developer plan that includes 10,000 messages, 500 guide active users, and 500 AI agent credits per month, with unlimited workflows and channels.
Knock was founded in January 2021 by Sam Seely and Chris Bell, former product and engineering leaders at Frame.io.
Knock's Starter plan costs 250 dollars per month for 50,000 messages, and Enterprise pricing is custom and based on volume, with usage-based overage charges billed monthly.
Knock is a hosted, managed notification infrastructure service, while Novu is an open-source project that companies can self-host for free as an alternative, trading managed reliability for infrastructure control.
Yes, Knock supports email, SMS, push notifications, in-app messages, chat, and Slack, all orchestrated through the same workflow engine.