ChatGPT officially launches advertising system

Core conclusion

On April 28, 2026, security researcher Jamie Larson (Buchodi's Threat Intel) released an in-depth technical analysis and disclosed the complete technical implementation of the ChatGPT advertising system. This is the first time that OpenAI has placed ads on a large scale in the free version of ChatGPT, marking the official entry of the AI ​​giant that originally advertised that "advertising is the last resort" into the advertising monetization track.

Key findings include:

• ChatGPT injects structured single_advertiser_ad_unit objects in the SSE stream, which are mixed with the model output and transmitted
• Each ad carries 4 Fernet encrypted click attribution tokens (AES-128-CBC + HMAC-SHA256)
• Ad selection based on semantic matching of conversation context (such as pushing Grubhub Chinese food takeout ads when discussing travel to Beijing)
• The merchant returns conversion data through OAIQ SDK (v0.1.3) to form a complete attribution closed loop
• Advertising creatives are hosted on OpenAI’s CDN (bzrcdn.openai.com), and merchants do not upload materials.

Key Points

• Time of incident: 2026-04-26 (advertising token minting time) / 2026-04-28 (public disclosure) -Affected objects: ChatGPT free version users, AI monetization practitioners, content marketing ecosystem
• Core changes: ChatGPT changes from a pure AI conversation tool to a hybrid with the attributes of an advertising distribution platform

Background and tracking process

This in-depth technical analysis comes from Buchodi's Threat Intel. The author used mobile traffic monitoring equipment to capture the complete link of the ChatGPT advertising system with user authorization and informed consent.

Sam Altman publicly stated less than two years ago: "I think advertising is the last resort in our business model. I will only consider it if we can't find other ways to allow everyone to use high-quality services." Now that the advertising is officially online, with 270+ points on Hacker News, community evaluation is polarized - some think it is "from idealism to realism", while others think it is a typical "dilution of original intention."

The core discussions in the Hacker News community (178 comments) focus on several directions: whether it is inevitable for AI companies to introduce advertising models, whether paying users will be affected by advertising, and the technical details of Fernet’s encrypted attribution system.

Key Impact (by Dimension)

Adaptation suggestions

The introduction of advertising in ChatGPT is both a challenge and an opportunity for independent developers and content creators in the field:

• If your products/services are targeted at ChatGPT users, you may consider becoming one of the first ChatGPT advertisers to obtain early traffic bonuses
• If your AI tool/SaaS is a paid subscription model, evaluate whether you need to add an advertising monetization layer to increase the conversion rate of the free version
• Study the attribution mechanism of OAIQ SDK - if OpenAI opens the advertising API in the future, this may become the Google Ads in the field of AI
• Pay attention to the impact of ChatGPT ads on existing SEO and content strategies: when part of the user's search behavior is transferred to chat, will the search results page ads be migrated to ChatGPT ads?

Task List

• Monitor whether ads related to your business field appear in the free version of ChatGPT
• Read Buchodi’s original article to learn about the complete technical implementation
• Evaluate whether to run ChatGPT advertising channels for your own products
• Update content distribution strategy to consider ChatGPT ads as a new customer acquisition channel

Example: Parsing Fernet token timestamp

Buchodi's technical article shows how to extract the minting timestamp from the ad token:

import base64
import struct
from datetime import datetime

# Fernet 9

# 1 （0x80）

# 2-9 8 Unix
b = base64.urlsafe_b64decode("gAAAAABp7fdA" + "==")
ts = struct.unpack(">Q", b[1:9])[0]
print(datetime.utcfromtimestamp(ts))

# : 2026-04-26 11:30:08 UTC

# 11:31:43

# 95

• Buchodi's Threat Intel: How ChatGPT serves ads
• Hacker News: 178
• The Verge: （）

， tools OpenAI、ChatGPT、Claude、n8n、LangGraph、OpenClaw、Hermes Agent

Internal link guidance

• Want to learn AI automation methods? Watch: How to build an AI content automated distribution system with n8n + ChatGPT: a complete 30-minute tutorial
• Want to know about the changes in the payment model of AI tools? Watch: A real case of a data analyst using Claude Code + n8n to build an automated report SaaS with a monthly income of $3,800
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