diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
new file mode 100644
index 00000000..0637f39d
--- /dev/null
+++ b/.github/copilot-instructions.md
@@ -0,0 +1,100 @@
+# Splitwiser - AI Coding Guide
+
+This document provides essential context for AI assistants working with the Splitwiser codebase.
+
+## Project Overview
+
+Splitwiser is an expense tracking and splitting application with:
+- Backend: FastAPI + MongoDB 
+- Frontend POC: Streamlit
+- Planned Frontend: Expo/React Native (in development)
+
+The app allows users to create groups, add expenses with flexible splitting options, track balances, and handle settlements.
+
+## Architecture
+
+### Backend (FastAPI)
+- Located in `/backend/`
+- RESTful API using FastAPI with Python 3.9+
+- MongoDB for database (nonrelational schema)
+- JWT authentication with refresh token rotation
+- Modular design with services:
+  - `app/auth/`: Authentication & user registration
+  - `app/user/`: User profile management
+  - `app/groups/`: Group creation & management
+  - `app/expenses/`: Expense tracking & splitting
+  
+### Frontend POC (Streamlit)
+- Located in `/ui-poc/`
+- `Home.py`: Entry point with login/registration
+- `pages/`: Contains main application pages
+  - `Groups.py`: Group management & expense creation 
+  - `Friends.py`: Friend balance tracking
+
+## Key Development Patterns
+
+### API Communication
+```python
+# Example API call with retry logic from Groups.py
+response = make_api_request(
+    method="get",
+    url=f"{API_URL}/groups/{group_id}",
+    headers={"Authorization": f"Bearer {st.session_state.access_token}"},
+    max_retries=3
+)
+```
+
+### State Management
+- Backend: MongoDB stores persistent data
+- Frontend: Streamlit session state manages user session
+```python
+# Session state initialization (see Home.py)
+if "access_token" not in st.session_state:
+    st.session_state.access_token = None
+```
+
+### Expense Handling
+- Support for different split types: equal, unequal, percentage-based
+- Each expense has a payer and multiple splits (recipients)
+- Settlements track debt resolution between users
+
+## Developer Workflows
+
+### Setup & Running
+1. Backend: 
+   ```bash
+   cd backend
+   pip install -r requirements.txt
+   uvicorn main:app --reload
+   ```
+2. Frontend POC:
+   ```bash
+   cd ui-poc
+   pip install -r requirements.txt
+   streamlit run Home.py
+   ```
+3. Test Data Generation:
+   ```bash
+   cd ui-poc
+   python setup_test_data.py
+   ```
+
+### Testing
+- Backend tests in `/backend/tests/`
+- Run tests with: `cd backend && pytest`
+- Test data setup script: `/ui-poc/setup_test_data.py`
+
+## Critical Files & Dependencies
+
+- `backend/main.py`: Main FastAPI application entry point
+- `backend/app/config.py`: Configuration settings
+- `backend/app/database.py`: MongoDB connection
+- `ui-poc/Home.py`: Streamlit application entry point
+- `ui-poc/openapi.json`: API specification for frontend reference
+
+## Common Tasks
+
+- Adding new API endpoint: Add route to appropriate service router file
+- Adding new UI component: Modify files in `/ui-poc/pages/`
+- Testing data flow: Use the `setup_test_data.py` to create test scenarios
+- Troubleshooting auth: Check JWT token handling in `app/auth/security.py`
diff --git a/nixpacks.toml b/nixpacks.toml
index d33c9431..0307f396 100644
--- a/nixpacks.toml
+++ b/nixpacks.toml
@@ -1,23 +1,17 @@
 [phases.setup]
 nixPkgs = ["python312", "pip"]
 
-# Completely override the install command to avoid duplicate processes
+# Use the default Python install behavior but ensure we use the right requirements file
 [phases.install]
 cmds = [
-    "python -m pip install --upgrade pip",
+    "pip install --upgrade pip",
     "pip install -r requirements.txt"
 ]
 
-# Skip Python's default install phase entirely
-[phases.python:install]
-dependsOn = ["install"] 
-cmds = []
-
 [phases.build]
 cmds = [
-    "echo 'Build phase complete'",
-    # Copy backend files to the root for simpler execution
-    "cp -r backend/* ."
+    "echo 'Build phase: Copying backend files'",
+    "cp -r backend/* . || echo 'Backend files already in place'"
 ]
 
 [start]
@@ -28,7 +22,5 @@ cmd = "uvicorn main:app --host 0.0.0.0 --port $PORT"
 PYTHONPATH = "/app"
 PYTHONUNBUFFERED = "1"
 
-# Specify we're using plain pip without a venv
+# Let Nixpacks handle virtual environment creation automatically
 [nixpacks]
-plan-path = "disabled"
-create-venv = false