Error Handling

Error Format

Handle errors gracefully to provide the best customer experience. All errors include clear codes and messages. Errors follow a consistent structure:

{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters",
    "details": [
      {
        "field": "amount",
        "message": "Amount must be positive"
      }
    ]
  }
}

HTTP Status Codes

Status Code	Meaning	Common Causes
`400`	Bad Request	Invalid parameters, validation errors
`401`	Unauthorized	Invalid or missing API key
`404`	Not Found	Resource doesn’t exist
`409`	Conflict	Duplicate resource, conflicting state
`422`	Unprocessable Entity	Payment declined, business logic error
`429`	Too Many Requests	Rate limit exceeded
`500`	Internal Server Error	Server error (rare)
`503`	Service Unavailable	Temporary service disruption

Error Codes

Client Errors (400-499)

Code	Status	Meaning	Action
`VALIDATION_ERROR`	400	Invalid request parameters	Check and fix parameters
`UNAUTHORIZED`	401	Invalid API key	Verify credentials
`NOT_FOUND`	404	Resource not found	Check resource ID
`DUPLICATE`	409	Resource already exists	Use existing resource
`DECLINED`	422	Payment declined by bank	Try different card
`INSUFFICIENT_FUNDS`	422	Customer has low balance	Contact customer
`EXPIRED_CARD`	422	Card has expired	Request new card details
`INVALID_CARD`	422	Invalid card number	Re-enter card information
`AUTHENTICATION_REQUIRED`	422	3DS authentication needed	Show 3DS challenge
`AUTHENTICATION_FAILED`	422	3DS verification failed	Allow customer to retry

Server Errors (500-599)

Code	Status	Meaning	Action
`INTERNAL_ERROR`	500	System error	Retry request with backoff
`SERVICE_UNAVAILABLE`	503	Temporary issue	Retry with exponential backoff

Handle Declined Payments

Show customer-friendly messages when payments are declined:

Declined Payment Response

{
  "error": {
    "code": "DECLINED",
    "message": "Payment declined by issuing bank",
    "declineReason": "insufficient_funds"
  }
}

Decline Reasons

Decline Reason	Customer-Friendly Message
`insufficient_funds`	”Payment couldn’t be processed. Please try a different card.”
`invalid_card`	”Unable to process this card. Please check your card details.”
`expired_card`	”This card has expired. Please use a different card.”
`card_declined`	”Payment couldn’t be completed. Please try another payment method.”
`processing_error`	”We’re having trouble processing this payment. Please try again.”

Best Practices

Use Generic Messages

Don’t expose specific decline reasons to customers. Use friendly, generic messages that don’t embarrass them.✅ Good: “Payment couldn’t be processed. Please try a different card.” ❌ Bad: “Insufficient funds in your account.”

Suggest Alternatives

When a payment is declined, suggest trying:

Another payment method
A different card
SPEI bank transfer (for large amounts)

Log Full Details

Log the complete error response for your records, but show simplified messages to customers.

Allow Retries

Let customers retry payments. Some declines are temporary (network issues, temporary holds).

Example: Handle Declined Payment

async function processPayment(paymentData) {
  try {
    const response = await cheqpay.payments.create(paymentData);
    return { success: true, payment: response };
  } catch (error) {
    // Log full error for debugging
    logger.error('Payment failed', { error, paymentData });
    
    // Show customer-friendly message
    if (error.code === 'DECLINED') {
      return {
        success: false,
        message: 'Payment couldn\'t be processed. Please try a different card.',
        allowRetry: true
      };
    }
    
    // Handle other errors...
  }
}

Retry Failed Requests

For temporary errors, implement retry logic with exponential backoff:

async function createPaymentWithRetry(data, maxRetries = 3) {
  for (let attempt = 0; attempt < maxRetries; attempt++) {
    try {
      return await createPayment(data);
    } catch (error) {
      // Only retry server errors
      const isRetryable = 
        error.status === 500 || 
        error.status === 503 ||
        error.code === 'INTERNAL_ERROR' ||
        error.code === 'SERVICE_UNAVAILABLE';
      
      if (!isRetryable || attempt === maxRetries - 1) {
        throw error;
      }
      
      // Exponential backoff: 1s, 2s, 4s
      const delay = Math.pow(2, attempt) * 1000;
      await sleep(delay);
    }
  }
}

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

Safe Retries with Idempotency

Thanks to idempotency, you can safely retry requests without creating duplicate charges:

const payment = await createPaymentWithRetry({
  externalId: 'order-12345', // Same ID = safe retry
  amount: 10000,
  currency: 'MXN',
  // ...
});

Always include an externalId to prevent duplicate charges when retrying failed requests.

Validation Errors

Handle validation errors before submitting:

{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters",
    "details": [
      {
        "field": "amount",
        "message": "Amount must be positive"
      },
      {
        "field": "customer.email",
        "message": "Email is invalid"
      }
    ]
  }
}

Client-Side Validation

Validate data before sending to API:

function validatePaymentData(data) {
  const errors = [];
  
  // Validate amount
  if (!data.amount || data.amount <= 0) {
    errors.push({ field: 'amount', message: 'Amount must be greater than 0' });
  }
  
  // Validate email
  if (!data.customer?.email || !isValidEmail(data.customer.email)) {
    errors.push({ field: 'email', message: 'Valid email required' });
  }
  
  // Validate card number
  if (data.paymentMethod.type === 'card') {
    const cardNumber = data.paymentMethod.options.card.number;
    if (!isValidCardNumber(cardNumber)) {
      errors.push({ field: 'cardNumber', message: 'Invalid card number' });
    }
  }
  
  return errors;
}

Handle Authentication Errors

Invalid API Key

{
  "error": {
    "code": "UNAUTHORIZED",
    "message": "Invalid API key"
  }
}

What to check:

API key is correct
Using the right environment (sandbox vs production)
Authorization header format: Bearer YOUR_API_KEY

Example

async function makeRequest(endpoint, data) {
  try {
    const response = await fetch(endpoint, {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${process.env.CHEQPAY_API_KEY}`,
        'Content-Type': 'application/json'
      },
      body: JSON.stringify(data)
    });
    
    if (!response.ok) {
      throw await response.json();
    }
    
    return await response.json();
  } catch (error) {
    if (error.code === 'UNAUTHORIZED') {
      logger.error('Invalid API key - check environment configuration');
      // Alert ops team
      sendAlert('API key issue detected');
    }
    throw error;
  }
}

Handle 3DS Errors

Authentication Required

{
  "paymentOrder": {
    "status": "PAYER_AUTHENTICATION_CHALLENGE_REQUIRED"
  },
  "payerAuthentication": {
    "stepUpUrl": "...",
    "jwt": "..."
  }
}

This isn’t an error - it means 3DS is required. Display the authentication challenge.

Authentication Failed

{
  "error": {
    "code": "AUTHENTICATION_FAILED",
    "message": "Customer failed to complete authentication"
  }
}

What to do:

Show friendly message: “We couldn’t verify your identity. Please try again.”
Allow customer to retry
Offer alternative payment method

3D Secure Guide

Learn how to implement 3DS authentication

Rate Limiting

If you exceed rate limits:

{
  "error": {
    "code": "RATE_LIMIT_EXCEEDED",
    "message": "Too many requests",
    "retryAfter": 60
  }
}

Handle Rate Limits

async function makeRequestWithRateLimit(endpoint, data) {
  try {
    return await makeRequest(endpoint, data);
  } catch (error) {
    if (error.code === 'RATE_LIMIT_EXCEEDED') {
      const retryAfter = error.retryAfter || 60;
      logger.warn(`Rate limited. Retrying after ${retryAfter}s`);
      
      await sleep(retryAfter * 1000);
      return await makeRequest(endpoint, data);
    }
    throw error;
  }
}

Contact [email protected] if you consistently hit rate limits. We can increase your limits.

Network Errors

Handle network connectivity issues:

async function makeRequestWithNetworkRetry(endpoint, data, maxRetries = 3) {
  for (let attempt = 0; attempt < maxRetries; attempt++) {
    try {
      return await makeRequest(endpoint, data);
    } catch (error) {
      // Check if it's a network error
      if (error.code === 'ECONNREFUSED' || 
          error.code === 'ETIMEDOUT' ||
          error.code === 'ENOTFOUND') {
        
        if (attempt < maxRetries - 1) {
          const delay = Math.pow(2, attempt) * 1000;
          logger.warn(`Network error, retrying in ${delay}ms`);
          await sleep(delay);
          continue;
        }
      }
      throw error;
    }
  }
}

Error Logging

Log errors for debugging and monitoring:

function logError(error, context) {
  logger.error('Payment error', {
    errorCode: error.code,
    errorMessage: error.message,
    statusCode: error.status,
    timestamp: new Date().toISOString(),
    context: {
      externalId: context.externalId,
      amount: context.amount,
      customerId: context.customerId
    },
    // Don't log sensitive data
    // cardNumber: NEVER LOG THIS
  });
  
  // Send to error tracking service
  if (process.env.NODE_ENV === 'production') {
    Sentry.captureException(error, { extra: context });
  }
}

Never log sensitive data like full card numbers, CVCs, or API keys.

Error Monitoring

Set up alerts for critical errors:

const errorThresholds = {
  DECLINED: 0.15,        // Alert if >15% decline rate
  INTERNAL_ERROR: 0.01,  // Alert if >1% server errors
  UNAUTHORIZED: 0.001    // Alert immediately
};

function trackError(error) {
  metrics.incrementError(error.code);
  
  const errorRate = metrics.getErrorRate(error.code);
  const threshold = errorThresholds[error.code] || 0.05;
  
  if (errorRate > threshold) {
    sendAlert({
      title: `High ${error.code} rate detected`,
      message: `${error.code} rate: ${(errorRate * 100).toFixed(2)}%`,
      severity: 'high'
    });
  }
}

Best Practices Summary

Use Customer-Friendly Messages

Show simple, non-technical error messages to customers. Log detailed errors for debugging.

Implement Retry Logic

Retry temporary failures with exponential backoff. Use idempotency to prevent duplicates.

Validate Client-Side

Validate data before sending to API to provide instant feedback and reduce errors.

Log Everything

Log all errors with context for debugging. Never log sensitive data like card numbers.

Monitor Error Rates

Track error rates and set up alerts for unusual patterns or critical errors.

Provide Fallbacks

Offer alternative payment methods when primary method fails.

Next Steps

Testing Guide

Test error scenarios in sandbox

Best Practices

Follow recommended patterns

API Reference

View complete error reference

Contact Support

Get help with errors

Getting Started

Essentials

Features

Guides

API Reference

OpenAPI Reference

Link Product API

Error Format

HTTP Status Codes

Error Codes

Client Errors (400-499)

Server Errors (500-599)

Handle Declined Payments

Declined Payment Response

Decline Reasons

Best Practices

Example: Handle Declined Payment

Retry Failed Requests

Safe Retries with Idempotency

Validation Errors

Client-Side Validation

Handle Authentication Errors

Invalid API Key

Example

Handle 3DS Errors

Authentication Required

Authentication Failed

3D Secure Guide

Rate Limiting

Handle Rate Limits

Network Errors

Error Logging

Error Monitoring

Best Practices Summary

Next Steps

Testing Guide

Best Practices

API Reference

Contact Support

Getting Started

Essentials

Features

Guides

API Reference

OpenAPI Reference

Link Product API

​Error Format

​HTTP Status Codes

​Error Codes

​Client Errors (400-499)

​Server Errors (500-599)

​Handle Declined Payments

​Declined Payment Response

​Decline Reasons

​Best Practices

​Example: Handle Declined Payment

​Retry Failed Requests

​Safe Retries with Idempotency

​Validation Errors

​Client-Side Validation

​Handle Authentication Errors

​Invalid API Key

​Example

​Handle 3DS Errors

​Authentication Required

​Authentication Failed

3D Secure Guide

​Rate Limiting

​Handle Rate Limits

​Network Errors

​Error Logging

​Error Monitoring

​Best Practices Summary

​Next Steps

Testing Guide

Best Practices

API Reference

Contact Support

Error Format

HTTP Status Codes

Error Codes

Client Errors (400-499)

Server Errors (500-599)

Handle Declined Payments

Declined Payment Response

Decline Reasons

Best Practices

Example: Handle Declined Payment

Retry Failed Requests

Safe Retries with Idempotency

Validation Errors

Client-Side Validation

Handle Authentication Errors

Invalid API Key

Example

Handle 3DS Errors

Authentication Required

Authentication Failed

Rate Limiting

Handle Rate Limits

Network Errors

Error Logging

Error Monitoring

Best Practices Summary

Next Steps