Hook0 is an open-source webhooks server that lets SaaS teams send event notifications to their customers' applications. Teams POST event types through a JSON REST API, and Hook0 routes, retries, signs, and logs each delivery from a management dashboard. It serves developers and product teams that need customer-facing webhooks with EU hosting, without building retry queues, signing, and observability themselves.[1][2]
Quick verdict
SaaS teams that need customer-facing event notifications benefit most from Hook0. Its fine-grained subscriptions, automatic retries, HMAC-signed payloads, and dashboard replay cover the tedious parts of webhook delivery. The constraints are licensing and scale cost: the server is SSPL-1.0 rather than OSI-approved open source, and the free tier stops at 100 events per day. If your team ships events to customer endpoints and accepts those terms, choose Hook0; if you need OSI-approved licensing or higher free volume, research alternatives separately.[1][2][3]
Key features
REST event ingestion REST event ingestion: applications POST event types through the JSON REST API instead of building their own fan-out endpoint.[1]
Fine-grained subscriptions Fine-grained subscriptions: each consuming application subscribes to the event types it needs, so tenants receive only their relevant traffic.[1][2]
Automatic retries Automatic retries: Hook0 re-sends deliveries until the receiver acknowledges them or the maximum attempt count is reached.[1][2]
HMAC-signed payloads HMAC-signed payloads: every delivery carries a signature computed with the subscription secret, which receivers verify before trusting the event.[1][2]
Delivery monitoring dashboard Delivery monitoring dashboard: operators watch per-delivery status and history from the web interface instead of grepping logs.[1]
Failure replay Failure replay: failed deliveries can be re-sent from the dashboard after the receiving endpoint is fixed.[1][2]
Organization event scoping Organization event scoping: events are scoped to a single organization, keeping multi-tenant traffic isolated.[1][2]
Self-host or hosted EU cloud Self-host or hosted EU cloud: run the SSPL-1.0 server with Docker Compose or Kubernetes manifests, or use the vendor-hosted EU platform.[1][2]
Who will love it
SaaS teams shipping customer-facing event notifications: subscriptions, retries, signing, and logs cover the tedious webhook infrastructure in one place.[1][2]
European teams with data-residency expectations: the hosted platform runs in the EU, and self-hosting keeps data on operator infrastructure.[1][2]
Operators that want both options: start on the free cloud tier and move to SSPL self-hosting later without changing the event model.[1][2]
Who should avoid it
High-volume event producers on the free tier: Developer allows 100 events per day with extras blocked, so real workloads need a paid cloud plan (starting at EUR 59 per month) or usage overage.[1]
Shops requiring OSI-approved licensing: the server is SSPL-1.0, a source-available license, with only the client SDKs under MIT.[1][2]
Teams without backend capacity: self-hosting means operating Postgres-backed Compose or Kubernetes infrastructure, and consuming events always needs code.[1][2]
Alternatives and compatibility
Producers integrate through the JSON REST API or the vendor SDKs, and receivers verify HMAC signatures with their subscription secret.[1]
Deployment is a choice, not a migration: the same subscription model runs self-hosted via Compose or Kubernetes or on the hosted EU platform.[1]
No catalogue alternative is verified yet: compare general-purpose webhook services in separate research before treating any of them as a drop-in substitute.[1][2]
Questions worth asking
What is the best Hook0 alternative for non-technical users?
No verified catalogue alternative exists yet, so compare the hosted Hook0 tiers against general-purpose webhook services in separate research. Fully non-technical teams should avoid self-hosting entirely: the Developer cloud tier needs no infrastructure, while producing and verifying events still assumes developers on the team.[1][2]
Is Hook0 really no-code?
How much does Hook0 cost per month?
The Developer tier is free for 100 events per day. Paid cloud plans start at EUR 59 per month; extra events on paid plans are never blocked and are billed per event (EUR 0.003 on Startup, EUR 0.0001 on Pro), while extra events on the free tier return HTTP 429. Checked October 11, 2026.[1]
Sources and editorial review
Source research. Reviewed on October 11, 2026. Written by Sanjib Sah. AI assisted; reviewed by a human editor.
We have not run or tested this product.
- Hook0 homepage (official)
official · Observed October 11, 2026
Official homepage: webhook SaaS scope, dashboard, REST API, HMAC, EU hosting, free tier, SSPL server, MIT SDKs.
- Hook0 pricing (official)
official · Observed October 11, 2026
Official pricing: Developer, Startup, and Pro tiers with event quotas and overage; self-hosting via Compose or Kubernetes.
- What is Hook0 (official docs)
official · Observed October 11, 2026
Official concept docs: event types, subscriptions, retries, HMAC, monitoring, replay, organization scoping.
- Hook0 repository (official)
official · Observed October 11, 2026
Official repository: identity, Rust implementation, stars, creation date, homepage link, active status.
- Hook0 README (official)
official · Observed October 11, 2026
Repository README: open-source webhooks server and UI, SSPL badge, Docker-based operation.
- Hook0 LICENSE.txt (official)
official · Observed October 11, 2026
Repository license file: Server Side Public License version 1 text for the server.
Compared with these products
No explicit proprietary baseline is recorded.