file_storage

Pluggable file storage with two shipped backends — local filesystem and S3-compatible — plus a browse / upload / download admin UI. Backend selection is per-deployment (DB-backed setting), so you can switch from filesystem (dev / single-node) to s3 (prod) without code changes.

Install simple_module_file_storage[tasks] to include the matching simple_module_background_tasks package, then enable background_tasks and run its worker for asynchronous multipart-upload checksums. Run its beat scheduler as well for upload cleanup jobs. The extras combine as simple_module_file_storage[s3,tasks]. Without background_tasks, uploads still work; completed multipart uploads keep checksum_sha256 null. Streamed uploads compute their checksum inline.

ModuleMeta

Field	Value
name	FileStorage
route_prefix	/api/file-storage
view_prefix	/file-storage
depends_on	[] (optional: ["Settings"])

Routes

API

Method + path	Body / response	Permission
POST /api/file-storage/upload	multipart (file, optional public=true) → StoredFileOut (201)	file_storage.upload
GET /api/file-storage/files	?page=&per_page=&q=&content_type=&sort= → StoredFileListOut	file_storage.download
GET /api/file-storage/files/{file_id}	→ StoredFileOut	file_storage.download
PATCH /api/file-storage/files/{file_id}	{"public": bool} → StoredFileOut	file_storage.upload
GET /api/file-storage/files/{file_id}/thumbnail	?w= → image/webp	file_storage.download
GET /api/file-storage/files/{file_id}/download	→ 302 (S3) or stream (filesystem); honours Range (see Range requests)	file_storage.download
DELETE /api/file-storage/files/{file_id}	→ 204	file_storage.delete
GET /api/file-storage/public/{file_id}[/{filename}]	bytes (anonymous)	none, public files only
GET /api/file-storage/public/{file_id}/thumbnail	?w= → image/webp (anonymous)	none, public files only

Listing: search, filter, sort

GET /files takes q (case-insensitive substring of the original filename; % and _ match literally), content_type (an exact type, or a family ending in / such as image/) and sort — one of created_at, -created_at (default), name, -name, size, -size (anything else is a 422). name sorts case-insensitively; ties break on id so pages never overlap. total reflects the filters.

Thumbnails

GET /files/{id}/thumbnail?w= returns a Pillow-resized WebP, aspect ratio preserved, never enlarged. w is clamped to 32–1024 and snapped up to one of 64, 128, 256, 512, 1024 (default 256), so a file has at most five variants. Only image/jpeg, png, webp and gif (first frame) have thumbnails; everything else, including SVG, is 404. An undecodable image is 422 file_storage.bad_image, and an image over 25 megapixels, or a source over 20 MB, is refused before any decode (decompression-bomb guard; DecompressionBombWarning is an error). Only JPEG/PNG/WebP/GIF are ever opened (Pillow formats= allowlist), the sniffed format must match the declared type, animated images yield their first frame, metadata is not carried into the output, and at most two decodes run at once.

Variants are cached in the storage backend next to the original, under {key}.w{width}.webp: they survive restarts, are shared by all workers, are bounded by the width whitelist, inherit the tenant key prefix, and are deleted with the file. A cache hit never re-reads the original. A concurrent first request may render twice; both write identical bytes.

Public files

StoredFile.public (default false) opts a file into anonymous serving. Set it with public=true on upload or PATCH /files/{id}; both need file_storage.upload, so anyone who may add files may publish them. StoredFileOut carries public and, while public, public_url (/api/file-storage/public/{id}/{filename}), so consumers never build the URL themselves — an <img src> on a public page can use it, or .../public/{id}/thumbnail?w=256.

Public file reads are readable cross-origin: any origin, no credentials, GET/HEAD/OPTIONS, Range, If-Range and If-None-Match allowed, and Content-Range, Accept-Ranges, ETag and Content-Length exposed, so a page on another site can seek in a video or PDF. The DB-backed setting public_files_cors (default on) turns this off without a restart. With the S3 backend a read can redirect to a presigned bucket URL; the browser then applies the bucket's own CORS configuration, which you must set on the bucket.

The public routes are exempt from AuthMiddleware through register_public_routes (GET only; uploads, PATCH and deletes stay gated). Serving rules:

• Only public=True, non-deleted rows resolve; unknown, private and deleted ids are the same 404, so existence is not leaked.
• Tenancy: an anonymous request binds no tenant, so the single lookup by (unguessable) id runs under all_tenants() and requires public=True. Making a file public is the owner's explicit choice to publish it cross-tenant; nothing else is reachable this way.
• Cache-Control: public, max-age=3600, a checksum ETag (304 on If-None-Match) and X-Content-Type-Options: nosniff.
• Every public response carries Content-Security-Policy: default-src 'none'; style-src 'unsafe-inline'; sandbox (the security-headers middleware now keeps a CSP the response already set). Only an allow-list of types is served inline (and redirected on S3): common raster images, PDF, JSON, GeoJSON, plain text, CSV, opaque binaries (application/octet-stream, zip, gzip, protobuf / vector tiles) and audio/* / video/* / font/* minus any XML or HTML subtype (INLINE_SAFE_CONTENT_TYPES / INLINE_SAFE_FAMILIES). Everything else — HTML, SVG, any XML, scripts, unknown types, and malformed values such as text/html, — is forced to Content-Disposition: attachment and always streamed, so stored XSS on the app origin is not possible. The stored type is lower-cased and stripped of parameters before the check (media_types.is_active_content).
• Presigning backends (S3) answer with a 302 to the presigned URL, cached for at most half the signature's TTL; filesystem backends stream.

Range requests

Whenever bytes stream through the app (the download endpoint on a non-presigning backend, and the public route for filesystem backends or active content), a single Range is honoured so COG / PMTiles readers can fetch just the tiles they need:

• bytes=a-b, bytes=a- and the suffix form bytes=-n answer 206 Partial Content with Content-Range: bytes a-b/size and the slice's Content-Length. An end past the object is clamped to size - 1.
• A range starting at or past the end (or bytes=-0) is 416 with Content-Range: bytes */size.
• Multiple ranges, another unit, or a malformed header are ignored and the whole file is sent with 200 (RFC 9110 allows this). So is a request whose If-Range does not match the current ETag.
• Streamed responses advertise Accept-Ranges: bytes. Auth, ETag, Content-Disposition, Cache-Control and CSP headers are the same as for the full response.

Redirected (presigned) downloads are served by the object store, which handles Range itself. Always redirecting large downloads to a presigned URL, as an opt-in setting, is not implemented.

Direct, resumable uploads

Files above direct_upload_threshold_bytes (default 64 MiB) upload in parts through a session, so a dropped connection or a reload loses at most one part. The Files page does this automatically; API clients drive it themselves. All routes need file_storage.upload and act only on the caller's own sessions (anyone else's id is a 404).

Route	Purpose
POST /api/file-storage/uploads {filename, content_type, total_size, public}	Open a session. Checks the content-type allow-list, max_direct_upload_bytes (default 10 GiB) and the quota (stored bytes plus the declared size of every still-open session). Returns part_size (16 MiB, grown so the file needs at most 10,000 parts) and total_parts.
GET /uploads/{id}	The session plus the parts the backend holds — the source of truth for resuming.
POST /uploads/{id}/part-urls {parts: [n]}	Where to PUT each part: presigned S3 URLs (direct: true, bound to the part's length) or the app's own part route. Only part numbers 1..total_parts.
PUT /uploads/{id}/parts/{n}	Filesystem backend only: the part body, relayed through the app (capped at that part's exact size).
POST /uploads/{id}/complete {parts: [{n, etag}]}	Assemble, verify, create the StoredFile, publish FileUploaded. The assembled size must equal total_size; the maximum and the quota are re-checked against the stored object, and a violation deletes it. Retrying a completed session returns the same file.
DELETE /uploads/{id}	Abort and discard the parts.

Sessions expire after upload_session_ttl_seconds (24 h). With background_tasks installed, the hourly beat task file_storage.reap_stale_uploads aborts expired sessions and, on S3, orphaned multipart uploads older than twice the TTL that have this module's key shape and no active session (a bucket shared with other applications is left alone); without it, POST /uploads aborts the caller's own expired sessions. Completed and aborted session rows are deleted upload_session_retention_days (default 7) after their expiry, by the same task or, without background_tasks, by the caller's next POST /uploads (own rows only). file_storage.compute_checksum fills checksum_sha256 after completion when background_tasks is installed.

In the browser, parts go four at a time with per-part retry and backoff. The session id is kept in localStorage keyed by file name, size and last-modified time; after a reload, select the same file again and the page offers Resume upload or Start over. (Browsers cannot keep a file handle across a reload, so the file must be picked again.)

Known limitations:

• Two simultaneous PUTs of the same part on the filesystem backend can leave the part's data and ETag from different writers; complete then reports a mismatch and the client re-sends the part.
• The resume key is file name, size and last-modified time, so two tabs uploading an identical file share one session.
• A part shorter than expected is stored and refused with 400; it stays until the client re-sends the part (the resend overwrites it), and complete flags it as mismatched.

S3 setup

Parts are PUT by the browser straight to the bucket, so:

• CORS on the bucket must allow PUT from the app's origin and expose ETag:

  [{"AllowedOrigins": ["https://app.example.com"], "AllowedMethods": ["PUT"],
    "AllowedHeaders": ["*"], "ExposeHeaders": ["ETag"], "MaxAgeSeconds": 3000}]

• s3_public_endpoint_url is the endpoint browsers reach, when it differs from the one the server uses (s3_endpoint_url, e.g. an in-cluster MinIO hostname). Presigned URLs are signed for it, and the redirect for presigned downloads uses it too. Blank falls back to s3_endpoint_url.
• The endpoint's origin is added to the CSP connect-src automatically (for AWS defaults, the bucket's *.s3.<region>.amazonaws.com hosts).

New settings: direct_upload_threshold_bytes, max_direct_upload_bytes, multipart_part_size_bytes, upload_session_ttl_seconds, upload_session_retention_days, s3_public_endpoint_url. A backend opts in with supports_direct_upload = True and the DirectUploadBackend methods in file_storage.contracts.service; without it, POST /uploads answers 501 and the page never uses sessions.

View

Method + path	Inertia component	Permission
GET /file-storage/	FileStorage/Browse	file_storage.download

Public contracts

from file_storage.contracts import (
    StoredFileOut,
    StoredFileListOut,
    FileUploaded,
    FileDeleted,
    StorageBackend,
    StorageError,
    StorageNotFoundError,
    StorageBackendError,
    NotSupportedError,
    ConfigurationError,
)

Class	Purpose
StoredFileOut	File metadata: id, key, filename, content_type, size_bytes, backend, checksum_sha256, uploaded_by, created_at, public, public_url.
StoredFileListOut	items, total, page, per_page.
FileUploaded (event)	file_id, key, backend, size_bytes, uploaded_by. Topic: file_storage.file.uploaded.
FileDeleted (event)	file_id, key. Topic: file_storage.file.deleted.
StorageBackend (Protocol)	The backend interface (see Writing your own backend).
StorageError + subclasses	Raise these from a backend; the API maps them to 404 / 415 / 500.

Models

StoredFile (table file_storage_stored_file)

Column	Type	Notes
id	UUID	PK
tenant_id	str(50)	owning tenant, from MultiTenantMixin
key	str(512)	backend-relative path; unique per tenant
filename	str(255)	original upload filename
content_type	str(128)	sniffed / declared MIME type
size_bytes	int
backend	str(32)	"filesystem" or "s3" — recorded at upload time
checksum_sha256	str(64) | null	computed during stream-upload; null for a direct (multipart) upload until file_storage.compute_checksum runs (never, without background_tasks)
public	bool	default false; opt-in anonymous serving
extra_metadata	dict	per-backend extras
audit + soft-delete	from AuditMixin + SoftDeleteMixin

Indexes on (tenant_id, key) (unique), tenant_id, created_by, is_deleted.

Multi-tenancy

StoredFile is MultiTenantMixin (#383). Every route acts for the request's active tenant: another tenant's file id answers 404 exactly like an unknown one, listings and the browse screen's totals and facets count only the tenant's rows, and bulk delete skips ids it cannot see. The aggregate cache is keyed per tenant, and a write drops only the slots of the tenants it wrote (plus the unscoped slot).

New storage keys are {tenant_id}/YYYY/MM/DD/<uuid><ext>, so each tenant's objects live under their own backend prefix. Rows written before the adoption migration keep their un-prefixed key (the column stores the full path) and were back-filled into DEFAULT_TENANT_ID (branding's system images into the platform owner, below). A single-tenant install (multi_tenant off) stamps uploads with DEFAULT_TENANT_ID and reads every row; with multi_tenant on and no tenant bound, an upload fails closed before any bytes reach the backend.

Platform files. Files that belong to the install rather than to a tenant — branding's system logo and favicon — are written and read with platform=True on FileStorageService.upload / get / download / delete. They are owned by PLATFORM_TENANT_ID ("platform", exported by simple_module_db) and looked up under all_tenants() restricted to that owner, so they resolve from anonymous requests while no tenant's file can be reached that way. The id is reserved — is_valid_tenant_id refuses it, so no request, header, claim, task message, default_tenant setting or tenants organisation can ever be bound to it — and it is distinct from DEFAULT_TENANT_ID, the owner of a single-tenant install's ordinary rows. The adoption migration made only the files the system branding settings referenced platform files; every other existing row went to DEFAULT_TENANT_ID. Never re-stamp platform rows: a script adopting default_tenant must update WHERE tenant_id = 'default', never every row.

The bypass covers only the platform row. platform_scope flushes the session's other pending writes before lifting isolation — so they are stamped with, and checked against, the bound tenant as usual — and turns autoflush off inside, so a platform read cannot carry them through unguarded.

Platform files are not listed on any tenant's Files screen. A tenant's own branding images are ordinary tenant files (no platform=True), uploaded and served in that tenant's scope.

The audit-log label resolver names files across tenants on purpose: the audit log is a platform screen over every tenant's entries, each of which already records the filename.

The optional checksum task and upload reaper use the background-tasks worker. Any task that touches StoredFile outside a request must run under tenant_context(row.tenant_id) for per-tenant work, or all_tenants() for a deliberate platform-wide sweep.

Settings

DB-backed via register_module_settings; pydantic defaults seed at boot. Live edits under Files at /admin/settings/.

Field	Default	Purpose
backend	"filesystem"	active backend id (filesystem | s3)
fs_root_path	"./uploads"	root dir for the filesystem backend (resolved against repo root)
s3_bucket	""	required when backend="s3"
s3_region	""	required when backend="s3"
s3_access_key_id	""	optional — falls back to env / IAM if empty
s3_secret_access_key	""	optional
s3_endpoint_url	""	optional — set for MinIO / Cloudflare R2
s3_signature_version	"s3v4"	presign signature version; pinned so custom endpoints get SigV4
s3_presign_ttl_seconds	300	TTL for presigned GET URLs
max_file_size_bytes	100 * 1024 * 1024	upload limit (100 MB)
quota_bytes	None	Enforced on plain and resumable uploads: stored bytes plus unexpired active session reservations; None means unlimited aggregate storage. Usage follows file-listing tenant scope; platform uploads count platform-owned files separately. PostgreSQL serializes quota admissions until the recording transaction commits. Rejected plain uploads delete the uploaded object.
allowed_content_types	None	optional MIME-type whitelist; None ⇒ any

Backends

Filesystem (default)

Stores files on local disk under fs_root_path, sharded by the first two characters of the storage key (<root>/ab/abcd1234...) so a single directory doesn't blow up readdir. Path traversal is blocked. presigned_get_url() is unsupported — downloads stream through the API process.

S3

Async client built on aioboto3. aioboto3 is an optional dependency — install with uv add --optional s3 aioboto3 (or include it in your deployment's lockfile). Works against AWS S3 and any S3-compatible provider (MinIO, Cloudflare R2, …) by setting s3_endpoint_url. presigned_get_url() returns a time-limited URL so downloads don't have to round-trip through the API.

Writing your own backend

Implement the StorageBackend protocol:

from file_storage.contracts import StorageBackend, StoredFile


class GcsBackend(StorageBackend):
    backend_id = "gcs"
    supports_presigned_url = True

    async def put(self, key, stream, content_type, size): ...
    async def get(self, key): ...  # awaited; returns an AsyncIterator[bytes]
    async def get_range(self, key, start, end): ...  # end inclusive
    async def delete(self, key): ...
    async def exists(self, key) -> bool: ...
    async def presigned_get_url(self, key, ttl_seconds: int) -> str: ...

get and get_range must stream in bounded chunks (never buffer the whole object) and raise StorageNotFoundError from the awaited call, before the first byte. get_range(key, start, end) uses HTTP semantics — end is inclusive — and receives an already-validated 0 <= start <= end < size. A backend without get_range still works: the endpoints then ignore Range.

Register it in your module's register_settings so the file_storage service can pick it up. (The shipped two backends are wired into a private BACKEND_REGISTRY; see backends/__init__.py for the pattern.)

Permissions

Code	Granted to	Purpose
file_storage.upload	user, admin, tenant:member/admin/owner	upload files
file_storage.download	user, admin, tenant:member/admin/owner	list / get / download
file_storage.delete	admin, tenant:admin, tenant:owner; also user when multi_tenant is off	delete
file_storage.manage	admin, tenant:admin, tenant:owner	act on every file in the active tenant, not only one's own

With multi_tenant on, delete is an organisation-admin act: the platform user role, which every account holds, does not carry it (it would hand it to every tenant member). With multi_tenant off the install is the only tenant, so on_startup maps file_storage.delete onto user and ordinary users keep deleting their files.

Ownership. Every authenticated route — list, get, download, thumbnail, publish/unpublish, delete, bulk delete and the browse screen — acts only on the files the caller uploaded (created_by is their user id), unless they hold file_storage.manage. Someone else's file answers 404, exactly like an unknown id, and the browse screen's type and uploader filters list only the caller's own rows (the usage figure stays bucket-wide, as the quota is). The scope is passed explicitly by the endpoints (deps.get_owner_scope) to the service's owner= argument; internal callers such as branding and reapers pass none and stay unscoped, and anonymous public serving is unaffected.

Menu

Label	URL	Icon	Section	Group	Order	Roles
Files	/file-storage	files	SIDEBAR	Content	40	["admin", "tenant:owner", "tenant:admin", "tenant:member"]

Events

The module publishes:

• FileUploaded(file_id, key, backend, size_bytes, uploaded_by) — after the row is committed.
• FileDeleted(file_id, key) — after delete (soft or hard) commits.

Subscribe from any other module's register_event_handlers:

from file_storage.contracts import FileUploaded


class MyModule(ModuleBase):
    def register_event_handlers(self, bus):
        bus.subscribe(FileUploaded, self._on_uploaded)

    async def _on_uploaded(self, event: FileUploaded) -> None: ...

Inertia pages

• FileStorage/Browse.tsx — file list + upload dropzone; handles the upload progress + delete confirmation flow. Each row shows a "Public" badge and a make public / make private action.
• FileStorage/components/UploadDropzone.tsx — drag-drop upload child component.

Locales

Top-level keys in file_storage/locales/en.json: browse, table, actions, delete_dialog, toasts, errors. The errors namespace is keyed by error code (not_found, too_large, bad_type, backend_error, bad_image) so the UI can render a deterministic message per StorageError subclass.