# plone.pgthumbor

> Plone addon that offloads image scaling from Plone to Thumbor.
> Includes zodb-pgjsonb-thumborblobloader for Thumbor-side blob loading from PostgreSQL.

## Key concepts

- plone-pgthumbor: Plone 6 addon, replaces @@images with 302 redirects to Thumbor
- zodb-pgjsonb-thumborblobloader: Thumbor 7 loader, reads blobs from PostgreSQL blob_state table
- HMAC-signed URLs prevent arbitrary image transformation requests
- 3-segment authenticated URLs for non-public content (auth handler calls Plone REST service)
- Smart focal point detection via Thumbor
- S3 fallback for tiered blob storage
- Zero Pillow dependency in Plone process
- Zero ZODB write-on-read for image scales

## Architecture

Browser -> Plone (302 redirect with signed Thumbor URL)
Browser -> Thumbor (scale + cache + serve)
Thumbor -> PostgreSQL blob_state (or S3 fallback)
Thumbor -> Plone @thumbor-auth REST service (for non-public content)

## Documentation sections

- Tutorials: quickstart-docker
- How-to: install, configure-thumbor, configure-plone, deploy-production, enable-s3-fallback
- Reference: configuration, url-format, rest-api, changelog
- Explanation: architecture, security, why-thumbor, cloud-native