This is an upstream technical reference retained from the pinned documentation revision. Its diagrams, timings and implementation details are not measurements or release guarantees for Sydekyks. Validate differences against the selected fork release before using it operationally.
Run logs and files are stored in the database by default, but you can switch to S3 later without any migration; for most cases, the database is enough. It’s recommended to start with the database and switch to S3 if needed. After switching, expired files in the database will be deleted, and everything will be stored in S3. No manual migration is needed.

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How It Works

File storage and signed URLs When AP_S3_USE_SIGNED_URLS is enabled, the app never proxies file bytes. It mints a short-lived pre-signed URL and returns a 307 redirect, so the worker uploads (and the browser downloads) directly to S3. This keeps heavy file traffic off the API server. Without signed URLs, the app streams the bytes itself (worker → app → S3). Files split into two groups:
  • Execution data (run logs, step files, trigger & webhook payloads, flow bundle) - expires and is auto-cleaned. Its location follows AP_FILE_STORAGE_LOCATION (S3 or DB).
  • Permanent files (platform assets, profile pictures, sample data, package archives, project releases, flow-version backups, knowledge base) - always stored in Postgres.

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Environment Variables

Friendly Tip #1: If the S3 bucket supports signed URLs but needs to be accessible over a public network, you can set AP_S3_USE_SIGNED_URLS to true to route traffic directly to S3 and reduce heavy traffic on your API server.

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Google Cloud Storage (S3 Interoperability)

Google Cloud Storage works through its S3-interoperability endpoint: set AP_S3_ENDPOINT to https://storage.googleapis.com and use HMAC keys as the access key ID and secret. The AWS SDK (>= 3.729) defaults to CRC32 checksums and aws-chunked payloads on PutObject, which GCS’s S3-interop endpoint rejects with SignatureDoesNotMatch. Set these two environment variables on the app and worker containers to restore the old behavior: