head to head
Novu vs Knock
Open-source self-host versus polished hosted product.
What matters for teams building autonomous agents
An agent stack treats email as a two-way primitive. Inbound has to arrive as structured JSON a tool call can consume, sends have to be safe to retry when a model loop repeats itself, and every action needs an audit trail. A provider without inbound parsing only solves half the problem.
| Priority | Novu | Knock |
|---|---|---|
| Inbound parsing | No | No |
| Idempotency keys | Yes | Yes |
| Webhooks | Yes | Yes |
| Operating since | 2021 | 2021 |
| Event stream | Yes | Yes |
| Best published rate per 1,000 | Tiers not published in comparable form | Tiers not published in comparable form |
| Batch sending | Yes | Yes |
| SDKs | node, python, go, php, java, dotnet | node, python, go, ruby, php, elixir, java, dotnet |
| Multi-tenant | Yes | Yes |
For an agent that reads and writes email running inbound parsing into tool calls and model-generated sends that must not duplicate, Knock takes every priority that separates them here (SDK breadth), while Novu matches it on the rest. That ordering reflects this audience. Weigh the same table differently and the answer changes.
Side by side
| Feature | Novu | Knock |
|---|---|---|
| Webhooks | Yes | Yes |
| SDKs | node, python, go, php, java, dotnet | node, python, go, ruby, php, elixir, java, dotnet |
| Multi-tenant | Yes | Yes |
| Tagline | Open-source notification infrastructure. | Notification infrastructure with workflow engine. |
| Free tier | 30,000 events/mo on cloud, free self-hosted | 10,000 notifications/mo |
| Starts at | $250/mo (Business cloud) | $249/mo (Starter) |
| Pricing model | volume | volume |
| API | Yes | Yes |
| SMTP | No | No |
| Templates | rich | rich |
| React Email | Yes | Yes |
| Inbound | No | No |
| Idempotency | Yes | Yes |
| Dedicated IP | No | No |
| Deliverability | BYO provider. | Inherits the deliverability of the provider you BYO (Postmark, SendGrid, Resend). |
| DX score | 8/10 | 9/10 |
| Best for | Teams that want self-hostable notification infrastructure. | Teams that need multi-channel product notifications with preferences. |
Novu
pros
- ›Open source, MIT-licensed
- ›Self-hostable
- ›Active community
cons
- ›Self-hosting takes effort
- ›Cloud pricing competitive only above 1M events/mo
Knock
pros
- ›Strong workflow engine
- ›In-app feed component
- ›Deep SDK coverage
- ›Idempotency keys
cons
- ›Pricier than running your own; entry plan is steep
- ›Bring your own delivery provider