Self-host Langfuse v3 with Docker Compose: required components, secrets, first-run steps, and production warnings

Documented steps

1. Note the version landscape first: the v3 self-hosting architecture is the default for self-hosted OSS as of mid-2026. Langfuse v4 is a Cloud preview and self-hosted v4 is still under development per official docs.
2. Clone the repo and use its compose file: `git clone https://github.com/langfuse/langfuse.git && cd langfuse`.
3. Understand that all of these components are mandatory with no supported substitutes: langfuse-web and langfuse-worker (application), postgres (transactional DB), clickhouse (OLAP store for traces/observations/scores, with no alternative OLAP database supported), redis (Valkey-compatible, for queueing and caching), and an S3-compatible blob store (compose ships MinIO) for event, media, and export storage.
4. Before starting, replace every value marked `# CHANGEME` with a long random secret: SALT, ENCRYPTION_KEY, NEXTAUTH_SECRET, POSTGRES_PASSWORD, CLICKHOUSE_PASSWORD, REDIS_AUTH, MINIO_ROOT_PASSWORD, LANGFUSE_S3_EVENT_UPLOAD_SECRET_ACCESS_KEY, LANGFUSE_S3_MEDIA_UPLOAD_SECRET_ACCESS_KEY, LANGFUSE_S3_BATCH_EXPORT_SECRET_ACCESS_KEY.
5. Ensure ClickHouse and Postgres run with timezone UTC (the default). Verify with `SELECT timezone()` returning 'UTC'. ClickHouse must be 24.3 or newer for v3; if you plan a v4 upgrade later, 25.12 or newer is required.
6. Start the stack: `docker compose up -d`. Wait roughly two to three minutes until the langfuse-web-1 container logs 'Ready', then open http://localhost:3000.
7. Optionally auto-provision an org, project, user, and API keys on first boot with LANGFUSE_INIT_ORG_ID, LANGFUSE_INIT_PROJECT_ID, LANGFUSE_INIT_PROJECT_PUBLIC_KEY, LANGFUSE_INIT_PROJECT_SECRET_KEY, LANGFUSE_INIT_USER_EMAIL, and LANGFUSE_INIT_USER_PASSWORD.
8. Do not run this docker-compose.yml in production as shipped. The docs state it lacks high availability, scaling capabilities, and backup functionality; it is intended for local and development use. For production use Kubernetes/Helm or Langfuse Cloud, with externally managed and backed-up Postgres, ClickHouse, Redis, and S3.
9. If upgrading to v4 later, read the migration guide first: it introduces write-mode env vars (LANGFUSE_MIGRATION_V4_WRITE_MODE=legacy|dual|events_only) and requires ClickHouse 25.12+ plus SDK upgrades before final cutover.
10. Verified against current official docs on 2026-07-29: https://langfuse.com/self-hosting , https://langfuse.com/self-hosting/docker-compose , https://langfuse.com/self-hosting/upgrade/upgrade-guides/upgrade-v3-to-v4