Operations

Troubleshooting guide

Common issues and solutions

Events not being received

Symptoms: No webhook calls reaching your endpoint

Possible causes and solutions:

• Incorrect URL: Verify webhook URL configuration with Access support

• Firewall blocking: Check firewall rules allow HTTPS from Azure IP ranges

• Certificate issues: Ensure TLS certificate is valid and not expired

• Authentication failure: Verify credentials are correct and not expired

Diagnostic steps:

# Test endpoint accessibility
curl -X POST https://your-domain.com/webhook \
  -H "Content-Type: application/json" \
  -d '{"test": "data"}'

# Check TLS certificate
openssl s_client -connect your-domain.com:443 \
  -servername your-domain.com

# Verify DNS resolution
nslookup your-domain.com

Duplicate events received

Symptoms: Same transaction ID processed multiple times

Expected behaviour: RELAY's at-least-once delivery guarantee may send duplicates

Solutions:

• Implement robust idempotency checking using transaction Id

• Use database unique constraints on transaction ID

• Implement distributed locking for processing

• Cache processed IDs with appropriate expiry

Slow webhook responses

Symptoms: Webhook responses exceed 5 seconds

Impact: May trigger unnecessary retries

Solutions:

• Move processing to asynchronous queue

• Return 200 status immediately after validation

• Optimise database queries with appropriate indexes

• Scale infrastructure to handle load

• Implement caching for lookup data

High retry rates

Symptoms: Many events requiring retries before success

Investigate:

• Check webhook endpoint error logs

• Monitor response time patterns

• Review infrastructure resource usage

• Analyse database connection pool status

Solutions:

• Optimise slow database queries

• Increase infrastructure capacity

• Fix application bugs causing errors

• Implement circuit breaker pattern

Getting help

Support channels

EPOS Product Team:

• Email: [email protected]

• Response time: 24 business hours

• Escalation path: Available upon request

What to include in support requests:

• Transaction ID or event data causing issues

• Error messages and stack traces

• Timestamp of the incident

• Webhook endpoint URL (if relevant)

• Steps taken to troubleshoot

Additional resources

• Request complete example transaction catalogue

• Access test environment for integration development

• Technical integration workshops available

• Architecture review services for high-volume implementations

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API reference

For complete details on retrieving lookup data referenced in RELAY events:

Related API endpoints

The following Access EPOS Orders API endpoints provide additional context for RELAY transaction data:

Endpoint	Purpose	Documentation
/api/User/Users	Retrieve clerk/user information	Users API section
/api/License/LicenseInfo	Get location and configuration details	License API section
/api/Menu/Menus	Retrieve menu and seating area data	Menu API section
/api/Menu/MenuDetails	Get PLU and product details	Menu API section

Authentication for API lookups

API calls to retrieve lookup data require authentication via bearer token:

POST /Token
Content-Type: application/x-www-form-urlencoded

apikey={YOUR_API_KEY}&password={YOUR_PASSWORD}

Use the returned token in subsequent API requests:

GET /api/Menu/MenuDetails
Authorization: Bearer {YOUR_TOKEN}
Content-Type: application/json

See the Authentication section for complete details on API access.

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Changelog and updates

Version history

Version	Date	Changes
0.3	19/11/2025	Release version - Sales transaction events documented
0.2	06/11/2025	Pre-release - Added authentication and error handling details
0.1	25/08/2025	Initial draft - Basic architecture and integration approach

Upcoming features

• Wastage transaction events: Documentation in development

• Table movement events: Specification under review

• Real-time inventory updates: Integration capability planned

• Enhanced filtering options: Configure which events to receive

Staying informed

To receive notifications about RELAY updates:

• Subscribe to the EPOS Product Team newsletter

• Join the developer community forum

• Follow Access Hospitality technical blog

• Contact your account manager for major update briefings

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Next steps

For new integrations

1. Review this documentation thoroughly

2. Contact the EPOS Product Team to request test environment access

3. Implement your webhook endpoint following the guidance above

4. Complete integration testing in the test environment

5. Request production credentials after successful testing

6. Deploy to production and monitor initial operations

For existing integrations

1. Review the performance requirements to ensure your infrastructure can scale

2. Implement idempotency logic if not already present

3. Add monitoring and alerting for production visibility

4. Test failure scenarios to validate resilience

5. Document your integration for your team's operational procedures

Getting started checklist

• Read this complete documentation

• Contact EPOS Product Team for test access

• Design webhook endpoint architecture

• Implement authentication method

• Build event processing logic

• Add idempotency handling

• Implement error handling and logging

• Complete Phase 1-4 testing

• Deploy to production

• Monitor and optimise

For questions or to begin your RELAY integration, contact [email protected].