Dev tool founders, how did you find your first users? (i will not promote)

I’m building a developer tool that checks whether code changes break existing functionality. I’m comfortable with the technical side, but finding people willing to try it is where I’m stuck. For anyone who’s launched a dev tool, where did your first users come from? Direct outreach, developer communities, technical content, or something else? I’d also love to hear how you earned enough trust for someone to connect a tool to their codebase. What worked for you, and what turned out to be a waste of time?