Error codes

Check that all parameters (including Expression Constraint Language expressions) are correctly encoded.

Ensure you're passing a valid bearer token in the header: Authorization: Bearer XXX.

Tokens typically expire after 30 minutes – refresh if needed.

Verify your token claims and permissions. Use JWT.IO to debug tokens.

Some content requires authentication or licensing (for example, SNOMED CT). Authenticate to access restricted resources.

Requests that are too costly (for example, $expand on greater than 50,000 concepts) will fail. Contact us for bulk access options.

The Web Application Firewall (WAF) may block certain queries. If your request is valid, raise a helpdesk ticket to adjust WAF rules.

If your error is not listed, please contact us.