Knock
Notification infrastructure with workflow engine.
Knock is a workflow-based notification platform: define workflows in code or visually, route across channels (email, push, SMS, in-app), and let users manage preferences. Email is delivered via your provider of choice.
The question here is which one a backend engineer would rather operate. That means SDK depth in the language already in use, whether a retry can safely be replayed, how much the event log tells you when a customer says the email never arrived, and whether the pricing curve stays sane as volume grows.
Against password resets, receipts, and magic links shipped from application code, Knock covers developer experience, SDK breadth, idempotency keys, event stream, and webhook coverage, and does not cover operating track record. Whether that gap matters depends on how central those are to the build.
- DX score: 9/10
- SDKs: node, python, go, ruby, php, elixir, java, dotnet
- Idempotency keys: Yes
- Operating since: 2021
- Event stream: Yes
- Best published rate per 1,000: Tiers not published in comparable form
- Webhooks: Yes
- Deliverability: Inherits the deliverability of the provider you BYO (Postmark, SendGrid, Resend).
- Free tier: 10,000 notifications/mo
Inherits the deliverability of the provider you BYO (Postmark, SendGrid, Resend).
Teams that need multi-channel product notifications with preferences.
- › Strong workflow engine
- › In-app feed component
- › Deep SDK coverage
- › Idempotency keys
- › Pricier than running your own; entry plan is steep
- › Bring your own delivery provider
Features at a glance
| API | Yes |
| SMTP | No |
| SDKs | node, python, go, ruby, php, elixir, java, dotnet |
| Webhooks | Yes |
| Templates | rich |
| React Email | Yes |
| Batch send | Yes |
| Scheduled send | Yes |
| Suppressions | Yes |
| Multi-tenant | Yes |
| Inbound parsing | No |
| Event stream | Yes |
| Idempotency keys | Yes |
| Dedicated IP | No |