--- title: "Outbound webhooks" --- > Documentation Index > Fetch the complete documentation index at: https://kmworks.date/llms.txt > Use this file to discover all available pages before exploring further. # Outbound webhooks Every library event (`BookAdded`, `SeriesAdded`, `BookImported`, `ReadProgressChanged`, …) can be POSTed as `{event, timestamp, data}` JSON to configured URLs (`[webhooks]` in `config.toml`, env `KOMGA_WEBHOOKS_URLS` / `KOMGA_WEBHOOKS_EVENTS` / `KOMGA_WEBHOOKS_TIMEOUT` / `KOMGA_WEBHOOKS_SECRET`). Event names and `data` shapes match the SSE stream, plus full `series`/`book` DTOs mirroring the REST API on upsert events (`series` on SeriesAdded/SeriesUpdated, `book` on BookAdded/BookUpdated, null when the row is gone; everything else stays id-only), and carried-over `libraryName`/`readListName`/`collectionName`/`userEmail` on Library/ReadList/Collection/User events. Delivery is fire-and-forget through a bounded in-memory queue: 429/5xx and transport errors are retried up to 3 times with 1s/2s/4s backoff honoring `Retry-After`, other 4xx are dropped, and nothing is persisted. Every request carries `X-Kmrs-Event`; with `secret` set it is HMAC-SHA256 signed via `X-Kmrs-Signature: t=,v1=` over `.`. The Java version has no webhook support at all. Source: https://kmworks.date/server/enhancements/webhooks/index.mdx