Troubleshooting Quick Guide - FoxCloud OpenAPI

Note: This is a living document. As we gather feedback from integration partners, we will continuously add common issues and solutions here. If you encounter a problem not listed below, please reach out to our support team.

Q: I am receiving a 40256 (Illegal Signature) error. How do I fix it?
A: This usually indicates a mismatch in the signature generation logic. Double-check the following:

Literal \r\n: Use the 4-character literal string \r\n as the separator, not actual newline characters.

URL Matching: The URL used in the signature must exactly match the API path you are calling (for example, /op/v1/device/real/query).

Real-time Timestamp: Generate the timestamp in real time and keep it within the valid time window.

Q: How do I remove a device during testing or when an end user leaves the program?
A: Use the Platform-Level Offboard API from your backend.

Solution: Call POST /op/v0/vpp/oauth2/client/offboard using your OAuth token. This releases the device from your client_id without requiring an active end-user session.

Q: How do I handle an expired OAuth token?
A: OAuth tokens are valid for 24 hours. Your backend should track expiry and request a new token using client_id and client_secret before making further API calls.