Storage
Configure local filesystem or S3-compatible storage for asset uploads. The StorageAdapter interface lives at the bottom for custom-adapter authors.
Aphex uses a pluggable storage system for file uploads. By default it writes to the local filesystem so you can develop without setting anything up. For production you'll usually swap to S3, R2, or another S3-compatible backend.
Quick setup
The base template's src/lib/server/storage/index.ts picks an adapter at boot from environment variables:
import { s3Storage } from '@aphexcms/storage-s3';
import { createStorageAdapter } from '@aphexcms/cms-core/server';
import { env } from '$env/dynamic/private';
let storageAdapter;
if (env.R2_BUCKET && env.R2_ENDPOINT && env.R2_ACCESS_KEY_ID && env.R2_SECRET_ACCESS_KEY) {
storageAdapter = s3Storage({
bucket: env.R2_BUCKET,
endpoint: env.R2_ENDPOINT,
accessKeyId: env.R2_ACCESS_KEY_ID,
secretAccessKey: env.R2_SECRET_ACCESS_KEY,
publicUrl: env.R2_PUBLIC_URL || ''
}).adapter;
} else {
storageAdapter = createStorageAdapter('local', {
basePath: './static/uploads',
baseUrl: '/uploads'
});
}
export { storageAdapter };Leave the R2_* vars empty in .env. Files land in ./static/uploads/ and are served by SvelteKit's static handler at /uploads/.... Restart not required after upload.
R2_BUCKET=my-bucket
R2_ENDPOINT=https://<account>.r2.cloudflarestorage.com
R2_ACCESS_KEY_ID=...
R2_SECRET_ACCESS_KEY=...
R2_PUBLIC_URL=https://cdn.your-app.comFilenames get a timestamp + random suffix. The CMS skips its built-in local adapter when an S3 helper returns disableLocalStorage: true.
Default local adapter
When you omit the storage option from createCMSConfig entirely, Aphex spins up its own local adapter — different from the template's:
| Property | Default local (no template) | Template's static/uploads adapter |
|---|---|---|
| Storage path | ./storage/assets (private) | ./static/uploads |
| Serving path | /media/{id}/{filename} (CMS handler) | /uploads/... (SvelteKit static) |
| Access control | yes — passes through assetService | none — anyone with the URL |
| Cache-Control | max-age=31536000 (1y) | SvelteKit defaults |
| Max file size | 10 MB | configurable |
| Allowed MIME types | jpg / png / webp / gif / avif / pdf / text | configurable |
If you want the access-controlled /media/... serving without the template's pass-through, just delete the conditional in src/lib/server/storage/index.ts and don't set storage on the config at all.
Switching to S3
pnpm add @aphexcms/storage-s3s3Storage() returns { adapter, disableLocalStorage: true } so you can plug it straight into the config:
import { s3Storage } from '@aphexcms/storage-s3';
import { env } from '$env/dynamic/private';
const storage = s3Storage({
bucket: env.R2_BUCKET,
endpoint: env.R2_ENDPOINT,
accessKeyId: env.R2_ACCESS_KEY_ID,
secretAccessKey: env.R2_SECRET_ACCESS_KEY,
publicUrl: env.R2_PUBLIC_URL
});
export default createCMSConfig({
storage
// ...
});Options
Prop
Type
Provider snippets
s3Storage({
bucket: env.R2_BUCKET,
endpoint: env.R2_ENDPOINT, // https://<account>.r2.cloudflarestorage.com
accessKeyId: env.R2_ACCESS_KEY_ID,
secretAccessKey: env.R2_SECRET_ACCESS_KEY,
publicUrl: env.R2_PUBLIC_URL // your cdn / public bucket URL
});s3Storage({
bucket: 'my-bucket',
endpoint: 'https://s3.us-east-1.amazonaws.com',
accessKeyId: env.AWS_ACCESS_KEY_ID,
secretAccessKey: env.AWS_SECRET_ACCESS_KEY,
region: 'us-east-1'
});s3Storage({
bucket: 'my-bucket',
endpoint: 'http://localhost:9000',
accessKeyId: 'minioadmin',
secretAccessKey: 'minioadmin'
});Upload flow
When a file is uploaded via the admin UI or POST /api/assets:
Validation — MIME type and size are checked against the adapter's limits before anything touches disk.
Image metadata extraction — for images, Sharp extracts width, height, format, color space, dominant color, and ICC profile presence.
Storage — the file is stored via the adapter. S3 helpers generate unique filenames with a timestamp and random suffix.
Database record — an asset row lands in cms_assets with the metadata, storage path, and
adapter name. If the database write fails, the storage write is rolled back.
URL generation — every asset gets an access-controlled /media/{id}/{filename} URL,
regardless of backend. Variants are siblings of it: /media/{id}/w960-{configHash}.webp.
Image metadata
Sharp extracts the following on image upload:
| Field | Description |
|---|---|
width | Width in pixels |
height | Height in pixels |
format | Image format (jpeg, png, webp, …) |
space | Color space (srgb, rgb, …) |
channels | Number of color channels |
density | DPI if available |
hasProfile | Whether an ICC color profile is embedded |
hasAlpha | Whether the image has transparency |
dominantColor | Dominant RGB color |
Stored in the asset's metadata JSONB column.
Asset access control
Assets served through the CDN route /media/[id]/[filename] go through the same auth + capability stack as documents:
- Public assets — served without authentication.
- Private assets — fields marked
private: truein your schema require an authenticated session, or a signed URL. - Organization isolation — assets respect the same multi-tenant rules as documents. Parent orgs can read child org assets.
Every asset is proxied through this route by default, including S3 and R2 ones — the bytes are
read with the adapter's getObject and streamed back, so the checks above actually decide whether
the caller gets the file.
Older versions redirected S3/R2 assets straight to the bucket's public URL, which meant the access
checks ran and were then bypassed by the redirect — and broke outright on a private bucket. If you
relied on that redirect for bandwidth reasons, see signedDownloads below.
Proxying costs a round-trip through your app for every byte, which is the wrong trade for large files — a 200 MB video download shouldn't occupy a server process. Opt those out with a predicate:
export default createCMSConfig({
signedDownloads: {
// Access checks still run first: a signed URL is only ever minted for a
// request that was already allowed to read the file.
shouldUseSignedURL: (asset) => asset.size > 25 * 1024 * 1024,
expiresIn: 900 // seconds, default 15 minutes
}
});Requires getSignedUrl on the adapter. Without it the route proxies anyway rather than failing —
serving the file correctly beats refusing to serve it.
Private assets
Mark a field private: true and any asset uploaded into it requires authorization to read:
{ name: 'contract', type: 'file', private: true }
{ name: 'proofSheet', type: 'image', private: true }Both image and file fields support it. A request for a private asset without authorization gets
401; with a session belonging to another organization, 403. Private responses are always sent
Cache-Control: private, no-store, so they never land in a shared cache.
Privacy is resolved from the field an asset was uploaded into, recorded on the asset at upload time. An asset uploaded into a public field and later reused in a private one stays public. If you need an asset to be private, upload it through the private field — the media library passes the field along when you open it from one.
Signed URLs
A session is the wrong mechanism for a public-facing page: an <img>, a <video>, or a link in an
email carries no admin cookie. A signed URL grants one asset for a bounded window, so your app
can decide who may see a file and then hand them a link that proves it.
Set a secret:
export default createCMSConfig({
security: {
// Long and random; keep it out of source and stable across deploys.
assetSigningSecret: env.APHEX_ASSET_SIGNING_SECRET
}
});Then mint links server-side, where the secret lives — a load function, an API route, an email
renderer:
import { signAssetUrl } from '@aphexcms/cms-core/server';
export async function load({ locals }) {
const contract = await getContractFor(locals.user);
return {
// Valid for one hour, for this asset only.
url: signAssetUrl(
locals.aphexCMS.config.security?.assetSigningSecret,
`/media/${contract.assetId}/${contract.filename}`,
contract.assetId,
{ expiresIn: 3600 }
)
};
}The result is an ordinary URL on your own domain:
/media/b3f1c0de-…/contract.pdf?exp=1736450000&sig=8Qb2…Everything still runs through the media route, so range requests, image derivatives and access
checks all behave exactly as they do for any other asset. The bucket stays private and its key
layout stays invisible — unlike signedDownloads above, which redirects the viewer to a URL on the
storage provider.
What the signature covers. The asset id and the expiry, and nothing else. Not the filename,
which is cosmetic and would make a rename break live links. Not the requested width either — a
responsive srcset asks for the same image at several widths, so binding the width would mean a
signature per breakpoint. A signature answers "may this caller read this asset", not "which
rendition"; every derivative is the same picture, and the access decision is identical for all of
them.
Failure is closed. With no assetSigningSecret configured, signAssetUrl returns the URL
unchanged and verification always fails — so a misconfiguration costs access rather than granting
it. Expired, tampered and mismatched signatures are all rejected identically, without saying why.
Signed URLs are only needed for private assets. Public ones are served to anyone with the link, as in any CMS — signing them adds nothing.
Adapter tracking and migrations
Each asset row stores which storageAdapter was used (e.g. 'local' or 's3'). This enables:
- Safe migrations — move from local to S3 without breaking existing assets. Old files keep working through the local adapter while new ones flow into S3.
- Adapter mismatch warnings — deleting an asset stored by a different adapter logs a warning rather than silently dropping the row.
- Mixed storage — older assets on local storage continue to work after switching backends.
Custom adapters
Implement the StorageAdapter interface and pass the result to createCMSConfig({ storage }). Most users will never need to do this — start with the S3 helper unless you're integrating an unusual backend.
interface StorageAdapter {
readonly name: string;
// Core operations (required)
store(data: UploadFileData): Promise<StorageFile>;
delete(path: string): Promise<boolean>;
exists(path: string): Promise<boolean>;
getUrl(path: string): string;
// Required: `/media/:id/:filename` proxies every asset through this, which is
// what makes its access checks real. An adapter that can't read its own
// objects back can't serve them.
getObject(path: string): Promise<Buffer>;
// Info and health
getStorageInfo(): Promise<{ totalSize: number; availableSpace?: number }>;
isHealthy(): Promise<boolean>;
// Connection lifecycle (optional)
connect?(): Promise<void>;
disconnect?(): Promise<void>;
// Extended operations (optional — enable admin browsing, signed URLs)
listObjects?(options?: ListObjectsOptions): Promise<ListObjectsResult>;
copyObject?(sourcePath: string, destPath: string): Promise<boolean>;
getObjectMetadata?(path: string): Promise<StorageObjectMetadata>;
getSignedUrl?(path: string, expiresIn?: number): Promise<string>;
// Adopt the app's `upload.maxFileSize`, so the limit has a single home.
setMaxFileSize?(bytes: number): void;
}The name field identifies which adapter stored each file in cms_assets.storageAdapter, so it must be unique per backend. The required methods give you upload, delete, exists, URL generation and serving; the optional ones unlock in-app file browsing, pre-signed URLs, and full variant cleanup on delete.
getObject is required as of v1 — it was optional before. A custom adapter that doesn't
implement it will no longer type-check, and couldn't serve files anyway now that /media proxies.
Two optional methods are worth implementing even though nothing breaks without them:
listObjects— deleting an asset sweeps everything under its{assetId}/key prefix, which is how derivatives generated under a previous image config get cleaned up. The variant record is replaced wholesale when the config hash changes, so the database has no memory of those files; a prefix listing is the only thing that can still find them. Without it, deletion falls back to the recorded variants and older ones are orphaned in the bucket.setMaxFileSize— letsupload.maxFileSizebe the single place the limit is set. Without it your adapter keeps its own constructor value, and the two can disagree.
See also
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