Plex and PayPal integration

What moves between them

Invoices and payments flow primarily from Plex into PayPal. When an invoice is created or updated in Plex, ml-connector polls the REST API on a manufacturing-aligned schedule (typically daily or per-shift), extracts the invoice details and line items, and sends them to PayPal via the invoicing endpoint for customer notification. Payment confirmations from PayPal are received via webhooks, verified with RSA-SHA256 signature checks, and written back into Plex as payment records to close the corresponding sales orders. Reference data such as customer codes and product identifiers is mapped bidirectionally so invoice line items reference valid PayPal products.

How ml-connector handles it

ml-connector stores both Plex OAuth2 and PayPal OAuth2 credentials encrypted and manages two separate bearer token refresh cycles, since each system has different token lifetimes and scopes. On the Plex side, it polls the REST API on a configurable schedule aligned to manufacturing shift or daily close windows, extracting invoices filtered by modified_date. For each invoice, line items are mapped to PayPal product identifiers, and the complete invoice payload is sent to PayPal's invoicing endpoint to notify the customer. PayPal webhook events are received asynchronously on a registered HTTPS endpoint, RSA-SHA256 signatures are verified against PayPal's published keys before accepting the event, and payment confirmations are written back to Plex as payment records to close sales orders. Plex rate limits are not publicly documented, so ml-connector implements exponential backoff on HTTP 429 responses, and it tracks invoice send status in an audit log so retries do not result in duplicate invoices to customers.

A real-world example

A mid-sized discrete manufacturer in the automotive supply chain runs Plex for production planning, quality, and finance, and uses PayPal to accept payments from global customers and manage multi-currency settlements. Previously, the order fulfillment team manually copied invoice details from Plex into PayPal's invoicing system every few days, and payment confirmations had to be tracked separately and re-entered into Plex to close orders. With Plex and PayPal connected, each new or updated invoice in Plex automatically sends to PayPal, customers receive consistent invoice notifications, and when a customer pays via PayPal, the payment confirmation flows back into Plex and closes the sales order. The finance team no longer re-keys invoices and can reconcile payments daily without manual lookups.

What you can do

• •Sync invoices from Plex into PayPal on a configurable schedule with line items mapped to PayPal products.
• •Receive PayPal payment confirmations via webhooks with RSA-SHA256 signature verification and post them back to Plex.
• •Manage two separate OAuth2 credential flows with independent token refresh cycles for Plex and PayPal.
• •Map Plex customers and product identifiers to PayPal invoice recipients and product records for consistent line-item references.
• •Track every invoice send and payment confirmation with a full audit trail and handle retries without creating duplicate invoices.

Questions

Which direction does data move between Plex and PayPal?

Invoices flow from Plex into PayPal on a configurable schedule so customers are notified. Payment confirmations come back from PayPal via webhooks and are posted into Plex as payment records to close sales orders. Reference data such as customer codes and product identifiers are aligned bidirectionally to ensure line items reference valid PayPal records.

Does Plex support webhooks, or does ml-connector have to poll?

Plex offers no native webhooks, so ml-connector polls the REST API on a configurable interval, typically daily or per-shift, filtering by modified_date to detect new and changed invoices. PayPal can push payment events via webhooks, and ml-connector verifies each webhook with RSA-SHA256 signature checks before accepting it.

How does ml-connector handle OAuth2 on both sides?

Plex and PayPal use OAuth2 client credentials flows with different token lifetimes and scopes, so ml-connector manages two independent bearer token refresh cycles, caching each token and refreshing it when it approaches expiry or after a 401 response. Both credential sets are stored encrypted and rotated on a schedule aligned to each system's token lifetime.