Glossary
Quick reference for Hook0 terminology.
Core Concepts
Event
An occurrence of something happening in your system. Events have a type, payload, and optional labels.
Event Type
A schema defining a category of events. Format: service.resource.verb (e.g., user.account.created).
Subscription
Configuration that defines where and when to deliver webhooks. Links event types to a target URL with optional label filtering.
Webhook
The HTTP POST request Hook0 sends to your endpoint when an event matches a subscription.
Request Attempt
A single delivery attempt of a webhook. Hook0 tracks success/failure and retries failed attempts.
Labels
Key-value pairs attached to events for filtering. Used for multi-tenancy (e.g., tenant_id: "customer_123").
Authentication
Biscuit Token
Hook0's authentication mechanism. A bearer token format that supports:
- Fine-grained permissions
- Offline verification
- Token attenuation (delegation)
Format: EoQKCAoh...
See Security Model for details.
API Key
Only used for MASTER_API_KEY - the admin credential for initial setup. Not for regular authentication.
Infrastructure
Output Worker
The background process that delivers webhooks. Handles retries, rate limiting, and concurrent delivery.
PostgreSQL
Hook0's only database. Stores events, subscriptions, and delivery attempts.
Acronyms
| Acronym | Full Name |
|---|---|
| HMAC | Hash-based Message Authentication Code |
| SSPL | Server Side Public License |
| WaaS | Webhooks as a Service |
| GDPR | General Data Protection Regulation |