Automate KSeF Invoices from Sellf Purchases with n8n Workflow

Streamline Your Invoice Automation with n8n: Automate KSeF Invoices from Sellf Purchases

Take the hassle out of invoice processing and enhance your workflow efficiency with the perfect automation tool for SaaS operators and n8n enthusiasts. This n8n workflow seamlessly manages invoice generation by processing Sellf purchase webhooks and submitting accurate, KSeF-ready invoices through a self-hosted KSeF Gateway, ensuring compliance and convenience.

What this Workflow Does

• Receives a POST webhook from Sellf containing the raw request body and signature header.
• Securely verifies the webhook signature using HMAC-SHA256, instantly rejecting unauthorized requests with a 401 response.
• Processes valid requests in the background, ensuring prompt response time with a JSON OK reply.
• Filters the webhook event to identify purchase completions and extracts essential customer, order, and invoice data.
• Conditional invoice building: Only proceeds when an invoice request is accompanied by a valid NIP.
• Generates a KSeF-compatible invoice payload with seller details before posting to your designated KSeF Gateway endpoint.
• Logs the outcome by capturing the unique KSeF number or noting error feedback if submission fails.

Use Cases

• SaaS companies integrating seamless invoice processing for enhanced customer satisfaction and compliance.
• Automation engineers looking to reduce manual intervention in financial operations.
• Businesses leveraging n8n to streamline backend processes and ensure accuracy in financial records.

Technical Details

• Integration with Sellf and an array of n8n nodes including: webhook, if, set, code, switch, and sticky note for comprehensive workflow control.
• Requires deployment of a self-hosted KSeF Gateway for invoice submissions.
• Configurable elements include the webhook signing secret, KSeF Gateway base URL, seller details, and default VAT rate.