The PATHWAY project comprises methodological and developmental work in support of an application for a programme of research to coproduce and evaluate a new care pathway for people using mental health services who have underlying complex trauma. We are working with trauma survivors and mental health professionals in the NHS and the independent and grassroots sector to: 1) develop an outcomes framework and logic model underpinning a future evaluation; 2) establish a trauma-informed approach to conducting in-depth interviews about support for complex trauma; 3) establish the acceptability of using electronic clinical records to track and evaluate complex trauma care pathways.