Plugin API | Uploadcare docs

The Plugin API lets you extend the File Uploader without forking or patching the library. Plugins can add upload sources, custom UI activities, per-file actions, file transformation hooks, icons, translations, and config options as a self-contained unit.

What plugins can do

Capability	API method
Add a source to the picker	`registerSource`
Add a custom activity panel	`registerActivity`
Add a per-file action button	`registerFileAction`
Transform files before upload	`registerFileHook`
Register an SVG icon	`registerIcon`
Add translation strings	`registerL10n`
Declare a custom config option	`registerConfig`

In this section

If you are starting from scratch, begin with Plugin structure & registration, then move to Extension points.

Plugin structure & registration — how to write a plugin, register it, and clean up after it
Extension points — registerSource, registerActivity, registerFileAction, registerFileHook, registerConfig
Icons & Translations — registerIcon, registerL10n
Runtime API — pluginApi.config, pluginApi.activity, pluginApi.files
Activity UI — CSS classes and elements for building activity UIs
Complete example — full Unsplash source plugin walkthrough
Built-in plugins — plugins that ship with the uploader