Self-hosting Kilden

Kilden is built to be self-hostable, and self-hosting will be documented here when our open source release ships. No date promises — we’d rather publish it working than announced.

What you’d be running

The honest preview. Kilden is a small fleet of stateless services around four pieces of infrastructure — Kafka-compatible streaming, ClickHouse, Postgres, Redis, and S3-compatible object storage for replay:

SDKs / provider webhooks / external sources
        │
        ▼
   capture  ──►  events_raw (keyed by distinct_id)
                     │
                     ▼
                 enricher  ──►  Postgres (persons, identities)
                     │
                     ▼
              events_enriched (keyed by person_id)
               │        │         │          │
               ▼        ▼         ▼          ▼
          warehouse   campaign   CDP     live tail
          writer      matcher    sync        │
               │        │         │          ▼
               ▼        ▼         ▼        panel (websocket)
          ClickHouse  journeys  destinations
                      (PG) → scheduler → dispatcher → email provider
                                                          │
                                  provider webhooks ──────┘
                                  (re-enter through capture)

Session replay takes a parallel path: recording chunks go to object storage, only ~200-byte pointers travel through Kafka, and an indexer builds the session index in ClickHouse.

The properties that make it operable:

• Services are stateless — all state lives in the databases and consumer offsets, so everything scales horizontally and restarts are boring.
• At-least-once delivery with idempotent edges — every layer can retry safely; deduplication by client-generated UUIDs makes it exactly-once where it counts.
• One write path — every event enters through capture, so there’s exactly one thing to secure, rate-limit and monitor for ingestion.

Meanwhile

Kilden Cloud is the hosted version of exactly this architecture — same code, same guarantees. Everything else in these docs applies to both.