Debugging Apex API Calls

All API calls that invoke Apex support a debug facility that allows access to detailed information about the execution of the code, including any calls to System.debug(). The categories field of a SOAP input header called DebuggingHeader allows you to set the logging granularity according to the levels outlined in this table.

Element Name	Type	Description
category	LogCategory	Specify the type of information returned in the debug log. Valid values are: Db Workflow Validation Callout Apex_code Apex_profiling Visualforce System All
level	LogCategoryLevel	Specifies the level of detail returned in the debug log. Valid log levels are (listed from lowest to highest): NONE ERROR WARN INFO DEBUG FINE FINER FINEST

In addition, the following log levels are still supported as part of the DebuggingHeader for backwards compatibility.

Log Level	Description
NONE	Does not include any log messages.
DEBUGONLY	Includes lower-level messages, and messages generated by calls to the System.debug method.
DB	Includes log messages generated by calls to the System.debug method, and every data manipulation language (DML) statement or inline SOQL or SOSL query.
PROFILE	Includes log messages generated by calls to the System.debug method, every DML statement or inline SOQL or SOSL query, and the entrance and exit of every user-defined method. In addition, the end of the debug log contains overall profiling information for the portions of the request that used the most resources. This profiling information is presented in terms of SOQL and SOSL statements, DML operations, and Apex method invocations. These three sections list the locations in the code that consumed the most time, in descending order of total cumulative time. Also listed is the number of times the categories executed.
CALLOUT	Includes the request-response XML that the server is sending and receiving from an external web service. Useful when debugging issues related to using Lightning Platform web service API calls or troubleshooting user access to external objects via Salesforce Connect.
DETAIL	Includes all messages generated by the PROFILE level and the following. Variable declaration statements Start of loop executions All loop controls, such as break and continue Thrown exceptions * Static and class initialization code * Any changes in the with sharing context

The corresponding output header, DebuggingInfo, contains the resulting debug log. For more information, see DebuggingHeader in the SOAP API Developer Guide.