Appendix: API Error Codes

The following table lists the error codes returned when a user fails to call an API.

**Table 1** Error codes
HTTP Status Code	Error Code	Description	Solution
404	APIC.0101	The API does not exist or has not been published in the environment.	Check whether the domain name, method, and path are consistent with those of the registered API. Check whether the API is published. If the API is published in a non-production environment, check whether the X-Stage header in the request is the name of the environment.
500	APIC.0103	The backend does not exist.	Contact technical support.
500	APIC.0104	The plug-ins do not exist.	Contact technical support.
500	APIC.0105	The backend configurations do not exist.	Contact technical support.
400	APIC.0106	Orchestration error.	Check whether the frontend and backend parameters of the API are correct.
400	APIC.0201	Bad request.	Set valid request parameters.
413	APIC.0201	Request entity too large.	Reduce the size of the request body to less than 12 MB.
414	APIC.0201	Request URI too large.	Reduce the size of the URI to less than 32 KB.
494	APIC.0201	Request headers too large.	Reduce the size of request headers to ensure that the length of a single request header is less than 32 KB or the total length of all request headers is less than 128 KB.
502	APIC.0202	Backend unavailable.	Check whether the backend address configured for the API is accessible.
504	APIC.0203	Backend timeout.	Increase the timeout duration of the backend service or shorten the processing time.
401	APIC.0301	Incorrect IAM authentication information.	Check whether the token is correct.
403	APIC.0302	The IAM user is not authorized to access the API.	Check whether the user is restricted by a blacklist or whitelist.
401	APIC.0303	Incorrect App authentication information.	Check whether the request method, path, query parameters, and request body are consistent with those used for signature. Check whether the client time is correct.
403	APIC.0304	The app is not authorized to access the API.	Check whether the app has been authorized to access the API.
401	APIC.0305	Incorrect authentication information.	Check whether the authentication information is correct.
403	APIC.0306	API access denied.	Check whether you have been authorized to access the API.
401	APIC.0307	The token must be updated.	Update the token.
429	APIC.0308	The throttling threshold has been reached.	Wait until the request throttling period ends and access the API again, or change the request throttling threshold.
403	APIC.0401	Unknown client IP address.	Contact technical support.
403	APIC.0402	The IP address is not authorized to access the API.	Check whether the IP address is restricted by a blacklist or whitelist.
503	APIC.0404	Access to the backend IP address has been denied.	Use an available IP address to access the backend service.
403	APIC.0405	The app is not accessed from a trusted IP address.	Check whether the IP address is restricted by the client access control policy.
500	APIC.0601	Internal server error.	Contact technical support.
400	APIC.0602	Bad request.	Check whether the request is valid.
500	APIC.0605	Backend domain name resolution failed.	Check whether the domain name is correct and has been bound to a correct backend address.
500	APIC.0606	Failed to load the API configurations.	Contact technical support.
400	APIC.0607	The following protocol is supported: {xxx}	Use HTTP or HTTPS to access the API.
500	APIC.0608	Failed to obtain the admin token.	Contact technical support.
500	APIC.0609	The VPC backend does not exist.	Contact technical support.
502	APIC.0610	No backend available.	Check whether all backends are available.
500	APIC.0611	The backend port does not exist.	Contact technical support.
500	APIC.0612	An API cannot call itself.	Modify the backend configurations, and ensure that the number of layers the API is recursively called does not exceed 10.
500	APIC.0705	Backend signature calculation failed.	Contact technical support.