Visualizer API

This guide will help you set up a Neo4j database using the Neo4j Desktop application, connect it with the cardano-db-sync database, and integrate both with a Python application/back-fill script.

Prerequisites

• Neo4j Desktop application
• Cardano DB Sync PostgreSQL database
• Python 3.12
• Pip

Step 1: Setting Up Neo4j

Download and Install Neo4j Desktop

1. Download the Neo4j Desktop application from the official website.
2. Install the application following the instructions for your operating system.

Create a New Database

1. Open Neo4j Desktop.
2. Click on "New" under the "Local DBMS" section.
3. Give your database a name and set a password (remember this password for later).
4. Click "Create" to initialize the database.
5. Once created, start the database by clicking "Open".

Configure Connection Details

Ensure your Neo4j database is running and note down the connection details:

• URI: bolt://localhost:7687
• Username: neo4j
• Password: <your_password> (the password you set during database creation)

Step 2: Setting up Cardano DB Sync

Follow Cardano DB Sync Docker Guide

1. Follow the instructions found here.

Configure Connection Details

Ensure your cardano-db-sync-postgres instance is running, and note down the connection details:

• Database Name: cexplorer
• User: postgres
• Password: See cardano-db-sync/config/secrets/postgres_password file.
• Host: localhost

Step 3: Setting Up Python Environment

Install Python Dependencies

1. Create a virtual environment (optional but recommended):

python -m venv venv
source venv/bin/activate

2. Install required Python packages:

pip install -r requirements.txt

Connect to Databases

Create .env file

Create a .env file in the root directory of the project and add the following environment variables:

NEO4J_URI=bolt://localhost:7687
NEO4J_USER=neo4j
NEO4J_PASSWORD=<your_password>
POSTGRES_DB=cexplorer
POSTGRES_USER=postgres
POSTGRES_PASSWORD=<your_password>
POSTGRES_HOST=localhost

Step 4: Populating Neo4j

1. Ensure both Neo4j and Postgres databases are running.
2. Run your Python application. If you want to build the graph, you can use the following command:

python extract_transactions_to_graph_store.py

You may also configure the timerange for which you want to extract transactions by modifying the start_time and end_time variables in the script.

Additional Information

• Neo4j Cypher Query Language
• PostgreSQL Documentation
• Neo4j Python Driver Documentation
• Psycopg2 Documentation

Troubleshooting

• Ensure the Neo4j and PostgreSQL services are running and accessible.
• Verify the connection details (URI, username, password, host) are correct.
• Check for any firewall or network issues that might be blocking the connections.

If you encounter any issues, refer to the respective documentation or seek help from the community forums.