AI Engineering · July 5, 2025 · 1 min read
MyMindfulJournal: AI Mood Pattern Detection

Next.jsTypeScriptAISupabase
The Concept
Journaling is a powerful tool for mental clarity, but many people struggle to see the "big picture" of their emotional health. MyMindfulJournal was built to turn simple daily entries into a meaningful map of your mood. It’s not a therapist; it’s a mirror that reflects your patterns through data.
Key Features
- Private Journaling: Secure, encrypted storage using Supabase.
- Mood Analysis: An AI engine reads your entries to detect underlying emotions (joy, stress, anxiety, productivity) that you might not even realize you're expressing.
- Pattern Tracking: Over weeks and months, the app identifies correlations—like how your mood dips on Mondays or improves after you mention "exercise."
- Privacy First: Your entries remain yours. The AI only processes the text to extract emotional tokens, not to store or "know" your identity.
Technical Architecture
- Frontend: Next.js 15 for a fast, responsive UI.
- Backend/Auth: Supabase handles the heavy lifting of authentication and database management.
- AI Engine: A fine-tuned LLM pipeline that performs sentiment analysis and entity extraction on every entry.
- Visuals: Chart.js for rendering mood trends and heatmaps.
What I Learned
Building this required a deep dive into NLP (Natural Language Processing). I had to ensure the mood detection wasn't just "positive or negative" but understood nuance—the difference between "I'm tired but happy" and "I'm just tired." It taught me how to handle sensitive user data with the respect and security it deserves.