📘 AI Journal — React Native + Supabase Mobile App

• Journaling app built with React Native (Expo) and Supabase.
• Users can sign up, log in, and create journal entries, which are securely stored and retrieved from Supabase.
• User can also utilize AI Chat (deepseek-chat) to futher reflect and chat about their experience.

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Screenshots

Login / Account Creation Screens

Home Screen

Entries (History) Screen

Add New Entry Screen

AI Chat Screen

Profile Screen

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🚀 Features

• 🔐 Authentication using Supabase Auth
• 📝 Entries: Create, view, update, and delete your personal journal entries
• 💬 Chat History: Save and load chat sessions for each user
• ⚙️ Secure RLS (Row Level Security) so users only access their own data
• 🌈 Built with React Native + Expo for cross-platform mobile development

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🛠️ Tech Stack

• Frontend: React Native + Expo
• Backend: Supabase (PostgreSQL + Auth + Storage)
• Language: JavaScript / JSX
• Database: PostgreSQL with SQL-based schema and security policies

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🧩 Supabase Setup

1. Create a new project at Supabase.io
2. Go to the SQL Editor and paste the following schema:

-- === ENTRIES TABLE ===
CREATE TABLE entries (
  id BIGSERIAL PRIMARY KEY,
  title TEXT NOT NULL,
  content TEXT NOT NULL,
  sentiment SMALLINT,
  created_at TIMESTAMPTZ DEFAULT NOW(),
  user_id UUID REFERENCES auth.users NOT NULL
);

ALTER TABLE entries ENABLE ROW LEVEL SECURITY;

CREATE POLICY "Users can view their own entries"
  ON entries FOR SELECT USING (auth.uid() = user_id);

CREATE POLICY "Users can create their own entries"
  ON entries FOR INSERT WITH CHECK (auth.uid() = user_id);

CREATE POLICY "Users can update their own entries"
  ON entries FOR UPDATE USING (auth.uid() = user_id);

CREATE POLICY "Users can delete their own entries"
  ON entries FOR DELETE USING (auth.uid() = user_id);

-- === USERS TABLE ===
CREATE TABLE users (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  email TEXT UNIQUE,
  username TEXT,
  password TEXT,
  created_at TIMESTAMPTZ DEFAULT NOW(),
  updated_at TIMESTAMPTZ DEFAULT NOW()
);

ALTER TABLE users ENABLE ROW LEVEL SECURITY;

CREATE POLICY "Users can view their own profile"
  ON users FOR SELECT USING (auth.uid() = id);

CREATE POLICY "Users can update their own profile"
  ON users FOR UPDATE USING (auth.uid() = id);

CREATE POLICY "Users can insert their own profile"
  ON users FOR INSERT WITH CHECK (auth.uid() = id);

-- === CHAT HISTORY TABLE ===
CREATE TABLE chat_history (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id UUID REFERENCES auth.users NOT NULL,
  messages JSONB NOT NULL DEFAULT '[]'::jsonb,
  first_user_message TEXT,
  created_at TIMESTAMPTZ DEFAULT NOW(),
  updated_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE INDEX idx_chat_history_user_id ON chat_history(user_id);
CREATE INDEX idx_chat_history_created_at ON chat_history(created_at DESC);

ALTER TABLE chat_history ENABLE ROW LEVEL SECURITY;

CREATE POLICY "Users can view their own chat history"
  ON chat_history FOR SELECT USING (auth.uid() = user_id);

CREATE POLICY "Users can create their own chat history"
  ON chat_history FOR INSERT WITH CHECK (auth.uid() = user_id);

CREATE POLICY "Users can update their own chat history"
  ON chat_history FOR UPDATE USING (auth.uid() = user_id);

CREATE POLICY "Users can delete their own chat history"
  ON chat_history FOR DELETE USING (auth.uid() = user_id);

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⚛️ React Native Setup Guide

🌀 Clone the Repository

git clone https://github.com/petermartens98/Journal-Buddy-AI-Powered-Journaling-React-Native-Mobile-App
cd Journal-Buddy-AI-Powered-Journaling-React-Native-Mobile-App

🚀 Initialize Expo Project

expo init AiJournalApp

🔐 Environment Variables

Create a .env file in the project root:

touch .env

Add your keys:

SUPABASE_URL=your-supabase-url
SUPABASE_KEY=your-supabase-anon-key
DEEPSEEK_API_KEY=your-deepseek-api-key

📦 Install Dependencies

npm install
# or
yarn install

▶️ Run the Project

npx expo start