Container web server

Learn about how to run a web server inside your Actor, which enables you to communicate with the outer world via both UI and API.

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Each Actor run is assigned a unique hard-to-guess URL (e.g. kmdo7wpzlshygi.runs.apify.net), which enables HTTP access to an optional web server running inside the Actor run's Docker container. The URL is available in the following places:

• In the web application, on the Actor run details page as the Container URL field.
• In the API as the containerUrl property of the Run object.
• In the Actor run's container as the ACTOR_WEB_SERVER_URL environment variable.

The web server running inside the container must listen at the port defined by the ACTOR_WEB_SERVER_PORT environment variable (typically 4321). If you want to use another port, simply define the ACTOR_WEB_SERVER_PORT environment variable with the desired port number in your Actor version configuration - see Custom environment variables for details.

The following example demonstrates how to start a simple web server in your Actor:

JavaScript

// npm install express
import { Actor } from 'apify';
import express from 'express';

await Actor.init();

const app = express();
const port = process.env.ACTOR_WEB_SERVER_PORT;

app.get('/', (req, res) => {
    res.send('Hello world from Express app!');
});

app.listen(port, () => console.log(`Web server is listening
    and can be accessed at
    ${process.env.ACTOR_WEB_SERVER_URL}!`));

// Let the Actor run for an hour
await new Promise((r) => setTimeout(r, 60 * 60 * 1000));

await Actor.exit();

Python

# pip install flask
import asyncio
import os
from apify import Actor
from apify_shared.consts import ActorEnvVars
from flask import Flask

async def main():
    async with Actor:
        # Create a Flask app
        app = Flask(__name__)

        # Define a route
        @app.route('/')
        def hello_world():
            return 'Hello world from Flask app!'

        # Log the public URL
        url = os.environ.get(ActorEnvVars.WEB_SERVER_URL)
        Actor.log.info(f'Web server is listening and can be accessed at {url}')

        # Start the web server
        port = os.environ.get(ActorEnvVars.WEB_SERVER_PORT)
        app.run(host='0.0.0.0', port=port)