Reverse Engineering and Automating Danmu Submission on Laifeng Live Platform with Python

The article begins with a brief motivation: a 2500‑CNY outsourced crawling project for the Laifeng live‑stream site, highlighting the need to understand how to send danmu (live comments) programmatically.

It then walks through the manual inspection of the target website (https://www.laifeng.com/), showing screenshots of navigating to a live room, logging in, and capturing the network request that carries the danmu payload.

Key parameters are identified: roomid (the live‑room ID), content (the comment text), t (a timestamp generated by (new Date).getTime() in JavaScript), and sign (a signature computed by a JavaScript function). The article explains how to locate these values in the request and why they are essential.

To reproduce the signature in Python, the author extracts the JavaScript source that builds sign . The code uses a series of bitwise operations similar to MD5. The tutorial shows how to run this JavaScript inside Python using execjs , passing the room data and timestamp to obtain the correct sign value.

Finally, a complete Python script is provided. It sets up request headers (including cookies), fetches the homepage to obtain a session, constructs the timestamp, calls the JavaScript function to get sign , and sends a POST request to the chat API endpoint with the required parameters. The script prints the server response, allowing the user to verify successful danmu delivery.

Readers are reminded to replace the placeholder cookies, room ID, and comment content with their own values before running the script. The article ends with a short JavaScript snippet that defines the signature algorithm for reference.