Chrome DevTools Protocol

0.4.0 verified Fri May 01 auth: no python

Python type wrappers for Chrome DevTools Protocol (CDP). Provides typed classes and enums for all CDP domains. Current version 0.4.0, updated infrequently.

pip install chrome-devtools-protocol

Common errors

error ModuleNotFoundError: No module named 'chrome_devtools_protocol' ↓

cause Incorrect import path. The actual module is 'cdp', not the package name.

fix

Use 'from cdp...' instead of 'from chrome_devtools_protocol...'.

error TypeError: Object of type Page is not JSON serializable ↓

cause Sending a CDP command class directly instead of calling its .to_json() method or using str().

fix

Call the command as a function that returns a dict: await ws.send(Page.enable()) sends a JSON string automatically.

Warnings

gotcha The package does not manage WebSocket connections. You must handle the WebSocket yourself (e.g., using websockets library). ↓

fix Install 'websockets' and manage WebSocket lifecycle manually.

deprecated The 'event_parsers' module is deprecated; use message dispatch via domain events. ↓

fix Refer to the cdp.event_dispatch or use domain event classes directly (e.g., from cdp.page import Page.domContentEventFired).

Imports

Page
wrong
```
import chrome_devtools_protocol.page.Page
```
correct
```
from cdp.page import Page
```
Common mistake: trying to import from the package directly instead of 'cdp' module.

Network

wrong

from chrome_debug import Network

correct

from cdp.network import Network

Wrong module name.

Quickstart

Connect to a CDP endpoint (e.g., Chrome debug port) and send a command.

import asyncio
from websockets import connect
from cdp import Page, Network

async def main():
    async with connect('ws://localhost:9222/devtools/browser/...') as ws:
        # Send a Page.enable command
        await ws.send(Page.enable())
        # Receive response
        response = await ws.recv()
        print(response)

asyncio.run(main())