Best Practices and Troubleshooting

Overview

To ensure a successful integration with Qolo’s Interact system, it is important to follow best practices for API implementation, error handling, and debugging. By proactively addressing common issues, clients can maintain efficient transaction processing, prevent authorization failures, and improve system reliability.

This section covers:

Recommended strategies for integrating Qolo’s APIs.
Common errors and how to resolve them.
Debugging techniques for troubleshooting API requests.

Recommended Implementation Strategies

1. Optimize Authorization Response Times

Ensure all authorization requests are processed within 3 seconds to prevent automatic declines.
Use efficient server infrastructure to minimize processing delays.
Implement asynchronous processing for non-critical operations to prevent slowdowns.

2. Implement Robust Error Handling

Log and track all API responses for debugging and reconciliation.
Gracefully handle declined transactions, ensuring customers receive clear decline reasons.
Use standardized response codes to classify different types of transaction failures.

3. Secure API Communication

Use encrypted connections (HTTPS) for all API calls to protect sensitive transaction data.
Authenticate API requests properly to prevent unauthorized access.
Monitor API logs for unusual activity or security threats.

Common Errors & How to Resolve Them

Error Type	Possible Cause	Resolution Steps
Authorization Timeout	Client system took longer than 3 seconds to respond.	Optimize processing speed and reduce latency.
Declined Transaction	Insufficient funds, blocked MCC, or fraud flag.	Provide a detailed decline reason in response.
Invalid API Key	Incorrect authentication credentials.	Verify API key configuration in your system.
Malformed JSON Request	Request payload has incorrect formatting.	Validate JSON structure before sending API calls.
Duplicate Transactions	Resubmitting an already processed transaction.	Check transaction status before retrying.

Debugging API Requests

1. Logging and Tracking API Calls

Enable detailed logging for all API calls and responses.
Store request and response data for troubleshooting.
Use unique identifiers (transaction IDs, timestamps) for tracking.

2. Testing in Sandbox Mode

Always test new implementations in Qolo’s sandbox environment before deploying to production.
Simulate authorization requests, declines, and refunds to ensure error handling works correctly.
Validate API responses against expected behavior.

3. Using API Response Codes for Debugging

Use Qolo’s response codes to diagnose transaction issues.
Compare expected vs. actual API responses to detect anomalies.
Ensure proper error messages are displayed to users when transactions fail.