Using Sockets

This is experimental

This feature is experimental and may change or be removed in future versions of Pyodide. This feature is only available in Node.js and is not supported in browsers.

By default, Pyodide does not support sockets in the browser. Browsers do not provide a standard low-level socket API, so Pyodide does not include a browser socket implementation and raises an error if your code tries to use sockets there.

If you are running Pyodide in Node.js, you can enable an experimental socket API.

Enabling socket support

Call await pyodide.useNodeSockFS() before importing any Python modules that use sockets.

const pyodide = await loadPyodide();
await pyodide.useNodeSockFS();

This feature requires JavaScript Promise Integration.

If you are using Node.js <= 24, enable it explicitly with the --experimental-wasm-stack-switching flag:

node --experimental-wasm-stack-switching

If you are using Node.js >= 25, Promise Integration is enabled by default.

After this setup, you can use sockets in Python as usual.

Example

Using sockets directly in Python

import socket

# Create a socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Connect to a server
s.connect(('localhost', 8080))
# Send some data
s.sendall(b'Hello, world')
# Receive some data
data = s.recv(1024)
print('Received', repr(data))
# Close the socket
s.close()

Using sockets with database drivers

Many database drivers use sockets to connect to a database server. With socket support enabled, you can use these drivers in Pyodide on Node.js.

For example, you can use the pymysql driver to connect to a MySQL database:

import pymysql

# Connect to the database
connection = pymysql.connect(host='localhost', user='user', password='password', database='test')
# Create a cursor
cursor = connection.cursor()
# Execute a query
cursor.execute('SELECT * FROM my_table')
# Fetch the results
results = cursor.fetchall()
print(results)
# Close the connection
connection.close()