When errors/exceptions occur in the system, the API Manager throws XML-based error responses to the client by default. To change the format of these error responses, you change the relevant XML file in the
<AM_HOME>/repository/deployment/server/synapse-configs/default/sequences directory. The directory includes multiple XML files, named after the type of errors that occur. You must select the correct file.
For example, to change the message type of authorization errors, open the
<AM_HOME>/repository/deployment/server/synapse-configs/default/sequences/_auth_failure_handler.xml file and change
application/xml to something like
Similarly, to change the error messages of throttling errors (e.g., quota exceeding), change the _throttle_out_handler_.xml file; resource mismatch errors, the _resource_mismatch_handler_.xml file, etc.
Given below are some error codes and their meanings.
API handlers error codes
|Error code||Error Message||Description||Examples|
This API has been blocked temporarily. Please try again later or contact the system administrators.
|Invoke an API which is in the BLOCKED lifecycle state|
|Message throttled out|
The maximum number of requests that can be made to the API within a designated time period is reached and the API is throttled for the user.
|Invoke an API exceeding the tier limit|
|Hard limit exceeded||Hard throttle limit reached||Invoke an API exceeding the hard throttle limit|
|Resource level throttle out||Message is throttled out because resource level has exceeded||Sending/Receiving messages beyond authorized resource level|
|Application level throttle out||Message is throttled out because application level is exceeded||Sending/Receiving messages beyond authorized application level|
Unclassified authentication failure
|An unspecified error has occurred||Backend service for key validation is not accessible when trying to invoke an API|
Invalid authentication information provided
The error codes
|When the access token is invalid or inactive.|
|No authentication information provided||Accessing an API without the Authorization: Bearer header|
Incorrect access token type is provided
The access token type used is not supported when invoking the API. The supported access token types are application and user accesses tokens. See Access Tokens.
|Invoke API with application token, where the resource only allows application user tokens|
No matching resource found in the API for the given request
|A resource with the name in the request can not be found in the API.||Invoke an API resource that is not available|
The requested API is temporarily blocked
|Happens when the API user is blocked.||Invoke API resource with a subscription that has been blocked by the API publisher|
|The user invoking the API has not been granted access to the required resource.||Invoke an unsubscribed API|
The subscription to the API is inactive
|The status of the API has changed to an inaccessible/unavailable state.||Invoke an API resource with a subscription that has not yet been approved by the administrator.|
The access token does not allow you to access the requested resource
Can not access the required resource with the provided access token. Check the valid resources that can be accessed with this token.
|Invoke API resource with an access token that is not generated to be used with the resource's scope.|
|Incomplete payload||The payload sent with the request is too large and the client is unable to keep the connection alive until the payload is completely transferred to the API Gateway||Sending a large PDF file with the POST request|
Sequences error codes
|Production/sandbox key offered to the API with no production/sandbox endpoint|
|Server cannot process the request due to an error in the request sent by the client|
|No matching resource found in the API for the given request|
In addition to the above error codes, we have engaged Synapse-level error codes to the default fault sequence and custom fault sequences (e.g.,_token_fault_.xml) of the API Manager. For information, see Error Handling in WSO2 ESB documentation.