Event Processing

Event Lifecycle

Every event goes through these stages:

1. 1. Ingestion — Event received via API
2. 2. Validation — Payload checked, rate limits applied
3. 3. Routing — Matching endpoints found
4. 4. Queuing — Delivery queued for each endpoint
5. 5. Delivery — HTTP POST sent to endpoint
6. 6. Verification — Response recorded, retry scheduled if needed
7. 7. Completion — Delivery marked as delivered or failed

Ingestion

When you send an event via POST /v1/webhooks, HookSniff:

1. 1. Authenticates your API key
2. 2. Checks idempotency key (returns cached response if duplicate)
3. 3. Validates event type format and payload size
4. 4. Checks rate limits
5. 5. Finds matching endpoints (active, matching event filter)
6. 6. Creates delivery records and queues them
7. 7. Returns 200 with delivery IDs

Routing

HookSniff finds all active endpoints that match the event type:

• Exact match: order.created matches only order.created
• Wildcard: order.* matches order.created, order.updated, etc.
• All: * matches everything (default)

Delivery

The worker picks up queued deliveries and sends HTTP POST requests:

1. 1. Signs the payload with HMAC-SHA256
2. 2. Adds Standard Webhooks headers
3. 3. Sends with 30s timeout
4. 4. Records the response (status code, body, timing)
5. 5. On 2xx: marks as delivered
6. 6. On failure: schedules retry or moves to DLQ

Payload İmzalama

Teslimattan önce, HookSniff payload'ı HMAC-SHA256 kullanarak imzalar:

• İmza: v1,{base64(hmac_sha256(secret, body))}
• Zaman damgası: webhook-timestamp (Unix saniye)
• Teslimat ID: webhook-id

Fanout

Bir olay birden fazla uç noktaya teslim edilebilir. order.created'ı dinleyen 5 uç noktanız varsa, HookSniff 5 ayrı teslimat oluşturur — her birinin kendi imza gizli anahtarı, tekrar politikası ve teslimat takibi vardır.

Sıralama

HookSniff olayları uç nokta başına FIFO sırasıyla teslim eder. Her teslimat bir sıra numarası içerir. Bir teslimat başarısız olup tekrar denendiğinde, aynı uç noktaya yapılan sonraki teslimatlar tekrar tamamlanana kadar bekletilir.