OpencellInstall

Overview

The Opencell Invoice: Validate Invoice operation in n8n is designed to validate invoices associated with a specific billing run in the Opencell system. This node is useful for automating financial workflows where you need to programmatically trigger invoice validation after a billing process, ensuring that all generated invoices are checked and ready for further processing (such as sending to customers or archiving).

Common scenarios:

• Automating end-of-billing-cycle processes.
• Integrating Opencell invoice validation into larger finance or ERP workflows.
• Ensuring data integrity before moving invoices to the next stage.

Practical example:
After generating invoices for a monthly billing run, use this node to validate all invoices in that run before notifying your accounting team or triggering downstream automation.

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Properties

Name	Type	Meaning
Authentication	options	Selects the authentication method for connecting to Opencell (Basic Authentication or OAuth2).
Billing Run ID	number	The unique identifier of the billing run whose invoices should be validated.
Invoices	fixedCollection	A collection of invoice IDs to be validated within the specified billing run.
Body Content Type	hidden	Internal property; always set to "multipart-form-data". Not user-configurable.

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Output

• The output is a JSON object containing the response from the Opencell API after attempting to validate the specified invoices.
• The structure of the output will depend on the Opencell API's response for the validation endpoint, but typically includes status information, any errors encountered, and possibly details about each invoice processed.

Example output:

{
  "status": "SUCCESS",
  "validatedInvoices": [
    {
      "invoiceId": 123,
      "result": "VALIDATED"
    },
    {
      "invoiceId": 124,
      "result": "VALIDATED"
    }
  ]
}

Note: Actual fields may vary depending on Opencell's API.

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Dependencies

• External Service: Requires access to an Opencell instance with API enabled.
• Authentication: Needs either Basic Authentication credentials or OAuth2 credentials configured in n8n.
• n8n Credentials: You must set up either opencellApi (for Basic Auth) or opencellOAuth2Api (for OAuth2) in your n8n instance.

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Troubleshooting

Common issues:

• Invalid Billing Run ID: If the provided Billing Run ID does not exist, the API will return an error.
• Missing or Incorrect Invoice IDs: If no invoices are specified or if invalid IDs are provided, validation will fail.
• Authentication Errors: Incorrect credentials will result in authentication failures.
• API Connectivity Issues: Network problems or incorrect Opencell API URLs can cause connection errors.

Error messages and resolutions:

• "Username/password error. Error code : XXX": Check your Basic Auth credentials.
• "Host error. Error code : XXX": Verify the Opencell API URL and network connectivity.
• "Invalid credentials (unknown error)": Double-check your authentication setup in n8n.
• API-specific errors (e.g., "Billing run not found"): Ensure the Billing Run ID and Invoice IDs are correct and exist in Opencell.

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Links and References

• Opencell Documentation
• n8n Docs: Creating Credentials
• n8n Docs: Custom Nodes