The Psyflex is a six-item self-report questionnaire assessing all six processes involved in ACT in a state form with high temporal specificity (last week).
The Psy-Flex measure is available https://psychologie.unibas.ch/en/faculty/centers/clinical-psychology-and-intervention-science/research/research-projects/psy-flex/#c24662
References:
Benoy, C., Knitter, B., Schumann, I., Bader, K., Walter, M., & Gloster, A.T. (2019). Treatment sensitivity: Its importance in the measurement of psychological flexibility. Journal of Contextual Behavioral Science, 13, 121-125. https://doi.org/10.1016/j.jcbs.2019.07.005
Gloster, A.T. et al (2021) Psy-Flex: A contextually sensitive measure of psychological flexibility. Journal of Contextual Behavioral Science, 22, 13-23. https://doi.org/10.1016/j.jcbs.2021.09.001 The Psy-Flex measure is in the Appendix.
Validation of Psy-Flex for Adolescents (PsyFlex-A): Soares, R., Cunha, M., Massano-Cardoso, I., & Galhardo, A. (2023). Assessing psychological flexibility in adolescents: Validation of PsyFlex-A . Portuguese Journal of Behavioral and Social Research, 9(1), 1–18. DOI: 10.31211/rpics.2023.9.1.284
Jo, D., Seong, B., & Yang, E. (2023). Psychometric properties of the Psy-flex scale: A validation study in a community sample in Korea. Journal of Contextual Behavioral Science, 30, 70-79. https://doi.org/10.1016/j.jcbs.2023.09.004