Step 1: Creating the Application

Before you can define any JSON-RPC methods, you need to create a Flask application. Flask-JSONRPC integrates seamlessly with Flask, so everything starts in exactly the same way.

In this step, you will:

• create a basic Flask application

• attach a JSON-RPC endpoint

• run your first RPC server

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Creating the Project

Create a project directory:

mkdir rpc_tutorial
cd rpc_tutorial

Create a file named app.py:

from flask import Flask
from flask_jsonrpc import JSONRPC

app = Flask(__name__)

# Attach the JSON-RPC endpoint at /api
jsonrpc = JSONRPC(app, "/api", enable_web_browsable_api=True)

if __name__ == "__main__":
    app.run(debug=True)

At this point you have a working JSON-RPC server — it just has no methods.

You can already start the application:

python app.py

You should see output similar to:

* Serving Flask app 'app'
* Debug mode: on
* Running on http://127.0.0.1:5000

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Opening the Explorer

Because you enabled the web-based API explorer, navigate to:

http://127.0.0.1:5000/api/browse

The explorer will show “No methods defined”, which is expected. In the next step, you will add your first method.