Knock: Deploy and Automate Product Messages Without a Custom Stack
A password reset, an onboarding note, and a product announcement shouldn’t each be its own engineering project. In a lot of companies, they are. Engineering owns the template, the channel, and the send. A copy change waits on a deploy. The person who wanted the message inside the product gets an email instead, or gets both. When someone asks whether it arrived, the history is split between the email vendor and a log nobody owns.
The claim window on a user’s patience is short. Too many messages, or the wrong channel, and they turn the channel off. A homegrown system can deliver the obvious send. It rarely gives the rest of the team a way to change it, pause it, or prove it landed.
Knock
Knock is notification infrastructure for product, growth, marketing, and engineering teams. Developers trigger each send from their own API, and the same system carries email, in-app, push, SMS, and chat.
Lifecycle messages, promotions, and transactional mail live in one place. A product manager can change a template or an in-app guide without shipping code. Engineering keeps environments, version history, and a way to roll back a bad change.
Preferences are part of the send, not a check someone remembers to add. A person can opt out by channel, workflow, category, or one-time broadcast, and Knock applies that choice before the message goes out. Batching, delays, and send windows keep a burst of events from becoming a burst of notifications.
Knock does not replace the inbox provider or the phone provider. You still pay those accounts. Teams commonly connect Postmark for email and Twilio for SMS, then let Knock decide which workflow step calls which provider.
Knock delivers hundreds of millions of messages per month.
Knock
The Developer and Starter plans publish a 99.9 percent uptime SLA. Delivery logs show the path from the template to the provider response, which a support team usually cannot reconstruct from the app alone.
Agents using the new notification center show approximately a 27% improvement in first response time and 32% faster ticket resolution rates compared to the previous system.
Knock, Gorgias customer story, December 2024
What You Can Configure
The pieces below are what a team sets up once and then runs. A workflow handles the repeating message. A broadcast handles the one-time send. A guide handles what the user sees inside the product.
- Agents: AI steps inside a workflow can research, qualify, enrich, and personalize a message before it is sent.
- Broadcasts: One-time sends go to an audience for an announcement, campaign, maintenance note, or newsletter.
- Channel Coverage: Email, SMS, push, an in-app feed, and chat can sit on the same workflow. Chat includes Slack, Microsoft Teams, Discord, and WhatsApp, with component kits for Slack and Microsoft Teams.
- Compliance and Access: Enterprise plans add HIPAA, SOC 2, GDPR, and CCPA programs, plus SSO and customer-managed sign-on.
- Environments and Rollback: Changes move through environments with commits, logs, and one-click rollback. An SDK covers the main backend languages, and a Model Context Protocol (MCP) server lets a team edit flows from Cursor or Claude.
- Guides: In-app modals, cards, banners, tooltips, and surveys can use Knock’s components or the product’s own.
- In-App Feed: A real-time feed, toasts, and banners are available on every plan, including React components for the inbox. Feed retention is unlimited on the published plans.
- Preferences and Send Windows: Opt-outs are stored per channel, workflow, category, and broadcast. Knock enforces them, and a send window can hold a message until an appropriate hour.
- Templates: Drag-and-drop editing, shared blocks, and global styles cover the message design. Email client previews are included from the Starter plan up.
- Tenants and Audiences: Recipients carry properties, segments can be static or dynamic, and an account can have its own branding. Per-customer branding and locked preferences are on Enterprise.
- Workflows: Event-driven flows cover order confirmations, password resets, onboarding, and retention. A step can batch, delay, branch, test a variant, throttle, call another system, or start another workflow.
Taken together, the workflow, the broadcast, and the guide give product and marketing one record of the message, the channel, and the preference that applied. Support can look up that record instead of asking engineering to grep a log.
Notification infrastructure is the most essential part of any product that I’d never dare build myself from scratch or operate at scale. Knock’s APIs allow me to focus on my front-end experience, while all the complexity is abstracted away.
Guillermo Rauch, Founder and CEO, Vercel
From Signup to the First Send
Identify each user with an ID, and add an email address, a phone number, a push token, or any custom property the message needs. Build a workflow, a broadcast, or a guide in the dashboard or in code. Trigger it from the API, from a source event, from a schedule, or from a change in audience membership. Knock routes the send through connected providers and the in-app feed, applying preferences, batching, delays, and conditions along the way.
Payment tiers are published on the site, with enterprise quoted by volume or notified users. A message is one delivery to one user on one channel, so in-app plus email counts as two. Bounces and sends blocked by a preference are not billed. Guide views do not count as messages. Past the Developer message cap, Knock does not cut off sending. They contact you about adding a billing method.
Knock publishes setup and product walkthroughs on its YouTube channel.
