Troubleshooting

Complete troubleshooting guidance for REST API integration.

Table 1. Common issues and resolutions
Issue	Possible cause	Resolution
REST API option disabled in UI	Feature not enabled	Set `yfs.sdf.restapi.enabled=Y` and restart OMS
Headers not propagated	Not whitelisted	Add headers to `yfs.rest.allowed.headers` property
401 Unauthorized errors	Invalid credentials	Verify JWT token, OAuth config, or certificate import
404 Not Found errors	Wrong URL	Verify external API URL is correct
Variables not resolving	Syntax error	Check syntax: `${prop}`, `/xpath`, `$.json`, `#{h:header}`, `#{q:param}`
JSON not working	Missing configuration	Add service to `yfs.xmljson.wrapjson.forflows` property
Connection timeout	Network/firewall issue	Check network connectivity, increase timeout value
Certificate errors with None auth	Certificate not imported	Import external API certificate into OMS keystore
OAuth token refresh fails	Invalid OAuth config	Verify client ID, secret, and token URL

Frequently asked questions

Can I use JWT authentication?

Yes, but JWT is not available in the UI dropdown. Configure it using custom headers with the Authorization header.

How do I add custom headers to the whitelist?

Set the yfs.rest.allowed.headers property with comma-separated header names. Default is Authorization,Content-Type,Accept,X-*.

Can I override incoming headers?

Yes, by specifying a different value in the service definition. The configured value takes precedence.

What if my API requires Basic Authentication?

Configure it using custom headers with Authorization: Basic <base64-encoded-credentials>.

How do I test if the feature is enabled?

Go to Service Definition UI > Add API and check if REST API radio button is enabled and not grayed out.

Can I use both XPath and JSONPath in the same service?

Yes, but XPath only works with XML input and JSONPath only works with JSON input.

How do I troubleshoot variable resolution issues?

Enable debug logging with yfs.yfs.10=verbose and check logs for variable resolution details.