// Create TeX engine options for no format upon ObjectTeX engine extension.
TeXOptions options = TeXOptions.consoleAppOptions(TeXConfig.objectIniTeX());
// Specify a file system working directory for the input.
options.setInputWorkingDirectory(new InputFileSystemDirectory(Utils.getInputDirectory()));
// Specify a file system working directory for the output.
options.setOutputWorkingDirectory(new OutputFileSystemDirectory(Utils.getOutputDirectory()));

// Run format creation.
TeXJob.createFormat("customtex", options);

// For further output to look fine.
options.getTerminalOut().getWriter().newLine();