I keep building tools nobody asked for but I wish existed.
cosskill.com lets you rehearse difficult conversations with AI personas before you have them for real. Breakups, salary negotiations, workplace confrontations, tough feedback.
You pick a persona (there are 20 — Stoic philosopher, NVC therapist, first-principles operator, etc.), type what you'd actually say, and see how it lands. The persona pushes back instead of agreeing with you.
Why I'm posting here:
- Free, no account, no email, no credit card, no trial
- No personal data stored on servers
- Built on Next.js + Cloudflare Workers + DeepSeek
- I'm a solo dev and this is a side project
What it's NOT: therapy, Character.AI entertainment, or celebrity impersonation. The personas are thinking frameworks (Socratic questioning, Nonviolent Communication, cognitive behavioral reframing), not chatbot cosplay.
The most-used personas are the relationship ones. People type things at 2am they'd never say out loud. Turns out the main use case is "help me figure out what to say before I send this text."
Happy to answer questions about the build, the AI stack, or why I thought this was a good idea.
