Knock
Email & MarketingCustomer engagement infrastructure for sending cross-channel product notifications, transactional messages, and lifecycle campaigns with developer-first tooling.
Knock is a notification infrastructure platform that enables product and engineering teams to build, manage, and send cross-channel messaging including email, SMS, push, in-app, and Slack notifications. Built with a developer-first approach, it offers a complete CLI, version control, environment management, and SDKs in 8+ languages making it compatible with AI coding tools like Cursor and Claude. The platform combines a visual workflow builder for non-technical teams with powerful APIs for developers, featuring batching, delays, user preferences, AI agents for workflow automation, and complete observability into notification delivery.
Best for
Product-led SaaS companies and engineering teams that need developer-friendly notification infrastructure with multi-channel support and want to enable non-technical teams to manage messaging.
Last updated: March 19, 2026
28/50
Overall Score
API Quality
10/10
GTM Relevance
18/20
PricingFreemium
Complexityeasy
Learningeasy
Visit knock.app →API Analysis
REST API
✓
Available
Webhooks
✓
Available
GraphQL
—
—
OAuth
✓
Available
slacksegmentamplitudemixpanelhubspotintercomzapiervercel
Pricing
freemiumFree Tier
Free tier available with usage-based pricing that scales based on messages sent per month. Enterprise plans include HIPAA, SOC2, GDPR compliance.
Strengths & Weaknesses
Strengths
Comprehensive SDK support across 8+ languages with excellent CLI tooling that works seamlessly with AI coding assistants like Cursor and Claude
True multi-channel orchestration with unified workflow engine supporting email, SMS, push, in-app, and Slack from a single platform
Built-in version control, environments, and CI/CD integration allowing teams to test and deploy notification changes like code
Complete observability with full notification history, delivery tracking, and debugging tools accessible to both technical and non-technical teams
Developer-friendly features including live previews, global styles, reusable blocks, and custom component support for in-app messaging
Weaknesses
Higher learning curve for non-technical users compared to pure marketing automation platforms despite the visual workflow builder
Pricing can scale quickly for high-volume use cases as it's usage-based on messages sent
Less robust marketing automation features compared to dedicated platforms like HubSpot or ActiveCampaign
Relatively newer platform compared to established players, though backed by impressive customer roster including Vercel and Webflow
Alternatives
Reviews
Links
FAQ
What is Knock?
Knock is a notification infrastructure platform that enables product and engineering teams to build, manage, and send cross-channel messaging including email, SMS, push, in-app, and Slack notifications. Built with a developer-first approach, it offers a complete CLI, version control, environment management, and SDKs in 8+ languages making it compatible with AI coding tools like Cursor and Claude. The platform combines a visual workflow builder for non-technical teams with powerful APIs for developers, featuring batching, delays, user preferences, AI agents for workflow automation, and complete observability into notification delivery.
Is Knock free?
Yes, Knock offers a free tier. Free tier available with usage-based pricing that scales based on messages sent per month. Enterprise plans include HIPAA, SOC2, GDPR compliance.
What are Knock alternatives?
Popular alternatives to Knock include Customer.io, Intercom, Segment, SendGrid, Mailgun. Compare features, API quality, and pricing on GTM Tools.
Does Knock have an API?
Yes, Knock provides a REST API. API quality is rated EXCELLENT. Documentation: https://docs.knock.app.
Who is Knock best for?
Product-led SaaS companies and engineering teams that need developer-friendly notification infrastructure with multi-channel support and want to enable non-technical teams to manage messaging.