mxHeadless
REST API gateway for headless frontends on MODX 3. Resources, objects, OpenAPI, API keys, and OAuth
HTTP caching
Public GET responses can be cached in the browser or CDN when mxheadless_cache_enabled=true.
Headers
On safe routes for anonymous callers:
text
Cache-Control: public, max-age=300
ETag: "a1b2c3d4e5f6..."max-age comes from mxheadless_cache_ttl (default 300 seconds).
Conditional GET
Send the ETag from a previous response:
bash
curl -s -D - https://example.com/api/v1/resources/5 \
-H 'If-None-Match: "a1b2c3d4e5f6..."'When the representation is unchanged, the server returns 304 Not Modified with no body.
Access-Control-Expose-Headers includes ETag so browser fetch can revalidate. See CORS.
Session and preview
Responses with a session, API key, or ?preview=true:
text
Cache-Control: private, no-storeDo not put them on a shared CDN.
Invalidation
Saving or deleting a resource clears object and list cache tags. For a headless frontend, use webhooks and ISR revalidation.