Google Cloud Storage holds binary media that does not belong in Firestore: direct chat/source uploads, generated assets, rendered clips, and downloadable content artifacts.
How Harmonia uses it
The web service creates short-lived signed upload and download URLs for tenant-scoped object names. Cloud deployments use a configured GCS_BUCKET; local development falls back to bounded files under the application data directory. Artifact metadata and workflow lineage remain in Firestore.
Deployment creates staging and durable-media buckets, enables uniform bucket-level access, restricts runtime identities, and configures CORS for the deployed web origin.
Security and authority
Object keys include tenant-derived scope. MIME type, size, completion state, and source rights are validated before an upload enters the pipeline. Signed URLs are short-lived and generated server-side. Bucket access does not grant publishing approval or workflow authority.
Failure behavior
Incomplete uploads, invalid object scope, disallowed media, missing artifacts, and storage errors remain explicit. Cloud mode does not silently write uploads to ephemeral container storage.
Evidence status
Storage contracts and local fallback behavior have automated coverage. Production claims require authenticated bucket/object evidence with secrets and signed query parameters redacted.
Relevant files
src/lib/chatAttachments.tssrc/lib/storage.tssrc/app/api/chat/attachments/infra/setup.shinfra/deploy.sh
Last modified on August 28, 2026
