Building a notification workflow
Notification and messaging infrastructure: one API and dashboard for email, in-app, push, SMS and Slack messages from your product
Knock has a free plan. Prices in US dollars as Knock's pricing page showed them on 11 October 2026.
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This is Knock, a New York company that provides messaging infrastructure for software products. One API and dashboard sends notifications by email, in-app feed, push, SMS and chat apps, so developers needn't build their own.
A visual workflow builder decides who is notified, on which channel and when, with steps for delays, batching and digests, branches, fetching data over HTTP, throttling and waiting for events. Workflows are triggered by API calls, usage events or audience changes.
Pre-built components add a real-time notification feed, inbox or toasts to a web or mobile app, or teams can build their own on the feed API. Each recipient can have as many in-app channels as needed.
In-app messages such as banners, paywalls, dialogs and nudges, rendered with a product's own components. Non-engineers can edit the copy and targeting from Knock, and guides can be ordered and throttled.
One workflow can send through email providers such as SendGrid, Postmark and Resend, SMS providers such as Twilio, Apple and Firebase push, and chat apps including Slack, Microsoft Teams, Discord and WhatsApp.
Recipients can choose which notifications they get and on which channels, and send windows hold messages until set hours in the recipient's time zone.
Templates, layouts, partials and translations are managed in one place with version control. A built-in agent can draft emails and workflows from a prompt in the team's existing layout and branding.
Knock takes in events from CDPs such as Segment and Rudderstack, reverse ETL tools such as Hightouch and Census, and apps like Stripe, Supabase, Clerk and PostHog, then builds audiences from attributes and events.
SDKs cover eight server languages, and the Knock CLI and MCP server let developers manage workflows from code, CI/CD and AI coding tools. Every API request, workflow run and message is logged for debugging.
Works with
Free
10,000 messages a month
$250a month
50,000 messages included, then $0.005 per message
Contact sales
Contact sales; volume or monthly notified user pricing
Prices in US dollars; the pricing page doesn't mention VAT or GBP. Only delivered messages are billed (one per person per channel); delivery providers such as Postmark or Twilio bill separately. Volume discounts are Enterprise only. Prices in US dollars, from Knock's pricing page on 11 October 2026. Knock may charge VAT on top, and prices can change.
“It has pretty much every feature an engineer might need”
“Knock is a very easy-to-use API that makes adding all sorts of user notifications to your application a breeze.”
Knock was founded in 2021 by Sam Seely and Chris Bell, and is based in New York. It grew out of a problem most product teams meet sooner or later: notifications start as a few emails and end up as a tangle of batching, preferences and logs that someone has to maintain.
Your app calls Knock's API when something happens. A workflow then decides who hears about it, on which channel, after what delay and whether to bundle it into a digest. Knock hands each message to a provider such as SendGrid, Postmark, Twilio or Apple Push, or shows it in its own in-app feed. React and mobile components cover the feed and in-app guides.
Knock fits engineering and product teams sending notifications over several channels. If a product only sends a handful of transactional emails, an email provider on its own is usually enough. Server SDKs cover Node, Python, Ruby, Go, Java, .NET, Elixir and PHP, and there is a CLI and an MCP server for working with AI coding tools.
The quickest way in is the free developer plan. You can build and test workflows in a sandbox mode that renders messages without sending them, so testing doesn't count towards usage. Batching and digests merge several events into one message, and preferences let a user opt out of a channel, which keeps messages down.
Knock has a free developer plan, a paid starter plan and a custom enterprise tier. Billing follows messages sent, in-app guide users and AI agent credits rather than team members or recipients. Prices are in US dollars, so a UK card is charged in dollars, and the delivery providers underneath bill separately. Check the pricing page for current figures.
Knock states that it holds SOC 2 Type 2 compliance and meets GDPR and CCPA requirements. It processes personal data in the US and certifies to the UK Extension of the EU-U.S. Data Privacy Framework, so UK teams should check the transfer arrangements with their data protection lead.
We don't currently list a confirmed discount code. That doesn't mean the store has no promotions; check its website for current prices.
Knock doesn't cut off notifications when a free account passes its limit. Its pricing page says it will get in touch about adding a billing method.
No. Billing is based on messages sent, in-app guide users and AI agent credits, not on seats or recipients.
Server SDKs cover Node, Python, Ruby, Go, Java, .NET, Elixir and PHP, with client components for in-app feeds and guides.
No. Knock routes product notifications across many channels. Teams mainly sending marketing email to large lists may find a newsletter tool better value.
Its privacy policy says personal information is processed and stored in the US, and no UK or EU hosting region is mentioned on its site.
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