Generic Origin Mode

CMS Assets has built-in support for Prismic, Contentful, Sanity, Shopify, Cloudinary, and Imgix, but you can also proxy any HTTPS asset origin by providing a custom origin URL in your tenant configuration.

Use cases

AWS S3 — Proxy assets from S3 buckets without exposing bucket URLs
Cloudflare R2 — Add caching and bandwidth tracking on top of R2
Google Cloud Storage — Route GCS-hosted media through CMS Assets
Legacy CMS servers — Proxy assets from self-hosted CMS installations
Any HTTPS origin — If it serves files over HTTPS, CMS Assets can proxy it

Tenant configuration

Select Generic Origin as the CMS type when creating or editing a tenant in the admin dashboard. Enter the full HTTPS origin URL in the Origin URL field. If your videos are hosted on a separate origin, fill in the optional Video Origin URL field.

You can also create generic origin tenants via the API by sending the origin URL as the originUrl field:

Example: S3 bucket

{
  "slug": "my-project",
  "cms": "generic",
  "originUrl": "https://my-bucket.s3.amazonaws.com",
  "websiteDomain": "my-site.com",
  "cacheTTL": 86400
}

With this configuration, a request to:

https://my-project.cmsassets.com/images/photo.jpg

Is proxied to:

https://my-bucket.s3.amazonaws.com/images/photo.jpg

Example: Cloudflare R2

{
  "slug": "my-r2",
  "cms": "generic",
  "originUrl": "https://pub-abc123.r2.dev",
  "cacheTTL": 604800
}

Example: Google Cloud Storage

{
  "slug": "my-gcs",
  "cms": "generic",
  "originUrl": "https://storage.googleapis.com/my-bucket",
  "cacheTTL": 172800
}

Separate video origin

If your videos are served from a different origin than images, you can configure a videoOrigin. In the admin dashboard, this field appears when Generic Origin is selected as the CMS type.

Via the API:

{
  "slug": "my-project",
  "cms": "generic",
  "originUrl": "https://images.my-cdn.com",
  "videoOrigin": "https://videos.my-cdn.com",
  "cacheTTL": 86400
}

Video file types (mp4, webm, mov, m4v) will be fetched from videoOrigin, while all other asset types use the primary origin.

Configurable options

Each tenant supports these configuration options:

Option	Type	Default	Description
`origin`	`string`	—	Primary HTTPS origin URL (required)
`videoOrigin`	`string`	—	Separate origin for video files
`cacheTTL`	`number`	`172800` (2 days)	Edge cache duration in seconds (60 – 2,592,000)
`allowedTypes`	`string[]`	— (all types allowed)	Content-Types to allow. If not set, all types are served
`stripQueryParamsFor`	`string[]`	— (query params included in cache key)	File extensions where query params are stripped from cache key
`blockedBotsRegex`	`string`	(default pattern)	Custom regex for blocking bots by User-Agent
`websiteDomain`	`string`	—	Your frontend domain, sent as `Referer` to origin

Response transformer with generic origins

Since v0.4.0, the response transformer has built-in support for generic origins via cms: "generic". Pass your origin URL as originUrl and all matching asset URLs in the response payload will be rewritten automatically:

import { transformCmsAssetUrls } from "@synchronized-studio/response-transformer"

const transformed = transformCmsAssetUrls(data, {
  cms: "generic",
  originUrl: "https://my-bucket.s3.amazonaws.com",
  cmsAssetsUrl: "https://my-project.cmsassets.com"
})

You can also use the dedicated transformGenericAssetUrls function directly:

import { transformGenericAssetUrls } from "@synchronized-studio/response-transformer"

const transformed = transformGenericAssetUrls(data, {
  originUrl: "https://my-bucket.s3.amazonaws.com",
  cmsAssetsUrl: "https://my-project.cmsassets.com"
})

Both approaches will rewrite URLs like https://my-bucket.s3.amazonaws.com/images/photo.jpg to https://my-project.cmsassets.com/images/photo.jpg, preserving the path and query parameters.

Notes

The origin must be HTTPS. HTTP origins are rejected.
The path structure is preserved 1:1 — the request path is appended directly to the origin URL.