Overview
The SuperSeeded Upload plugin provides a seamless way to add file upload capabilities to your WordPress site. It includes both a Gutenberg block and shortcode, making it easy to embed the upload widget anywhere on your site.Shortcode Support
Use
[superseeded_upload] in any post or pageGutenberg Block
Native block editor integration
Secure Token Proxy
API key never exposed to frontend
Customizable
Themes, file types, and size limits
Installation
Manual Installation
- Download the plugin from the API repository
- Upload to
/wp-content/plugins/superseeded-upload/ - Activate via Plugins > Installed Plugins
File Structure
Configuration
Navigate to Settings > SuperSeeded Upload to configure the plugin.Required Settings
Optional Settings
Merchant Token Mode
Controls how unique merchant tokens are generated for billing purposes:Merchant tokens are computed server-side from WordPress user/session identity and cannot be manipulated by the frontend. This ensures accurate per-user billing.
Post-Upload Processing Routes
The plugin can automatically call API routes after a file upload completes. Routes are discovered dynamically from the API and can be enabled/disabled in settings.
Post-Upload Processing settings with route checkboxes
- Resolve Specifications - Classify pot sizes and plant specifications (supports JSON, Excel, PDF, images)
Usage
Shortcode
Add the upload widget to any page or post:Shortcode Attributes
Merchant tokens are computed server-side based on the Merchant Token Mode setting and cannot be overridden per-shortcode for security reasons.
Example with Attributes
Gutenberg Block
- Open the page/post in the block editor
- Click the + button to add a block
- Search for “SuperSeeded Upload”
- Configure options in the block sidebar

JavaScript Events
The widget dispatches custom DOM events that you can listen to for integration with your theme or other plugins:Event Details
Styling
CSS Variables
Override the default styling with CSS custom properties:Theme-Specific Styles
Dynamic Content
If you’re loading content dynamically (AJAX, page builders), reinitialize widgets after the DOM updates:REST API Endpoints
The plugin registers REST API endpoints for token proxy and upload handling:Token Endpoint
Returns a delegation token for direct uploads to the SuperSeeded TUS endpoint. The merchant token is computed server-side based on the configured Merchant Token Mode.Upload Complete Endpoint
Called automatically when an upload finishes. Fires thesuperseeded_upload_complete action.
Resolve Specs Endpoint
Proxy for the SuperSeeded verify-pot-sizes API. Use this to process items and retrieve enriched data.For file uploads, the widget automatically calls the
/v1/verify/pot-sizes endpoint directly using the delegation token and the file URL. The superseeded:specs-resolved event fires when enrichment completes.All endpoints require authentication via WordPress nonce (
X-WP-Nonce header).PHP Hooks
The plugin provides WordPress actions that allow other plugins and themes to react to upload events.superseeded_upload_complete
Fires when an upload completes successfully. Use this to store upload records, trigger workflows, or integrate with other systems.superseeded_specs_resolved
Fires when the verify-pot-sizes API returns enriched data from a processed request via the WordPress proxy endpoint.JavaScript API
TheSuperSeededWordPress global object provides methods for programmatic control:
Server Notification Event
Listen for the server’s response after upload completion is recorded:Troubleshooting
Widget Not Appearing
- Check that the plugin is activated
- Verify your API key is configured in Settings
- Check browser console for JavaScript errors
Token Fetch Failed
- Verify your API key is correct
- Check that the merchant ID is configured
- Review server error logs for API responses
Uploads Failing
- Check file size limits in both plugin settings and WordPress/server config
- Verify the file type is in the allowed list
- Check browser network tab for specific error responses
Complete Example
Frontend Integration
Here’s a complete example integrating the upload widget with a custom thank-you message:Backend Integration (PHP)
Create a custom plugin or add to your theme’sfunctions.php to handle uploads server-side:
Plugin Source
The complete plugin source is available in the SuperSeeded API repository:View Plugin Source
Browse the plugin files on GitHub

