Storage layer

Object/blob storage is a separate composition layer from relational backend and third-party integrations.

packages/core/src/storage/          apps/web/src/storage/
├── blob-ports.ts (IBlobStore)      ├── config.ts           ← BLOB_PROVIDER, R2, tiering knobs
└── (Phase 1: registry, tiering)    ├── wire-storage.ts     ← composition helper
                                    └── providers/
                                        supabase/           ← code default (Supabase Storage)
                                        s3/                 ← R2 + MinIO
                                        tiered/             ← hot/cold facade — what OCI runs

How it fits

Layer	Responsibility	Env prefix
`backend/`	Postgres repos, auth session, admin	`NEXT_PUBLIC_BACKEND_PROVIDER`
`storage/`	Files: images, artifacts, vault assets	`BLOB_PROVIDER` (server), `NEXT_PUBLIC_BLOB_PROVIDER` (browser), `R2_`, `BLOB_COLD_`
`integrations/`	Zotero, GitLab, Mattermost, …	`NEXT_PUBLIC_*_PROVIDER`

Feature code uses IBlobStore via PaperImageStore — never Supabase Storage SDK directly.

Docs

../plans/completed/migration-plan.md — phased self-host (Postgres + tiered blobs, Supabase Auth)
tiering.md — R2 hot → OCI cold eviction formula
r2-setup.md — enable R2, create bucket, API token, env vars
growth.md — which database tables grow without bound, and what deletes them

What is actually running

The OCI deployment runs BLOB_PROVIDER=tiered — R2 (or S3-compatible) hot, MinIO on the OCI box cold, with the blob_objects registry tracking what is where. Set in the deployed environment, not in the repository: the env examples leave it commented out, so a fresh checkout still gets supabase.

Code default

BLOB_PROVIDER=supabase (or unset) → SupabaseBlobStore wired from wire-supabase-backend via wireStorage(). That is the default a new checkout gets, and what a hosted-Supabase deployment uses; it is not what this project runs on.

Tiered

BLOB_PROVIDER=tiered → TieredBlobStore (R2 hot, MinIO cold, blob_objects registry). See tiering.md for the eviction formula and r2-setup.md for the keys.