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Handle errors from the Billing SDK using structured error classes. Each error type provides specific information to help you debug issues and display appropriate messages to your users.

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Error classes

The SDK includes the following error types:
  • ValidationError - Invalid input or configuration (e.g., missing required fields, invalid field values)
  • APIError - API-level errors from the Funnelfox backend (e.g., invalid price, double purchase, payment failures)
  • PrimerError - Errors originating from the Primer SDK during payment processing
  • CheckoutError - Errors during the checkout lifecycle (e.g., initialization or state management issues)
  • NetworkError - Network connectivity or request failures

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Handle errors

You can catch and handle each error type to provide appropriate user feedback: 
import {
  ValidationError,
  APIError,
  PrimerError,
  CheckoutError,
  NetworkError,
} from '@funnelfox/billing';

try {
  const checkout = await createCheckout(config);
} catch (error) {
  if (error instanceof ValidationError) {
    // Invalid input
    console.log('Field:', error.field);
    console.log('Value:', error.value);
    console.log('Message:', error.message);
  } else if (error instanceof APIError) {
    // API error
    console.log('Status:', error.statusCode);
    console.log('Error Code:', error.errorCode); // e.g., 'double_purchase'
    console.log('Error Type:', error.errorType); // e.g., 'api_exception'
    console.log('Request ID:', error.requestId); // For support
    console.log('Message:', error.message);
  } else if (error instanceof PrimerError) {
    // Primer SDK error
    console.log('Primer error:', error.message);
    console.log('Original:', error.primerError);
  } else if (error instanceof CheckoutError) {
    // Checkout lifecycle error
    console.log('Phase:', error.phase);
    console.log('Message:', error.message);
  } else if (error instanceof NetworkError) {
    // Network/connectivity error
    console.log('Network error:', error.message);
    console.log('Original:', error.originalError);
  }
}

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Common error codes

  • double_purchase - User already has an active subscription
  • invalid_price - Price ID not found
  • invalid_customer - Customer data validation failed
  • payment_failed - Payment processing failed
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