How do I determine which version of Toolbox/JTOpen I have?

You can use the AboutToolbox utility, which is delivered as part of the Toolbox.  In older versions it was in the package named "utilities" and in version 9.8 and above is in the package named "util".   To use the utility, change to the directory where the jt400.jar package resides.  If you have jt400.jar already in your classpath, you can run run the following command:

java utilities.AboutToolbox

If you do not have jt400.jar already in the classpath or you are unsure you can run the following

If you have downloaded one of the newer versions of JTOpen from the GitHub site, it might look like this:

java -cp jt400-20.0.7-java11.jar utilities.AboutToolbox

It will produce something similar to the following output. In this case, using that last example with JTOpen release 20.0.7:

IBM Toolbox for Java:
Open Source Software, JTOpen 20.0.6 codebase 5770-SS1 V7R5M0.00 built=2023-11-02 03:05:40 (GMT)
Supports JDBC version 4.3
Toolbox driver version 13.3

You may also use the java.lang.Package class to query the release of JTOpen / Toolbox that you have.