ChatGPT Multi Pane Chrome extension replicates Codex logic without limits or extra costs

A developer from Habr has released a Chrome extension called ChatGPT Multi Pane — an experimental plugin that adds several parallel dialogue panels to the ChatGPT.com interface. In terms of functionality, it reproduces key features of OpenAI's Codex, but without a paid subscription and without strict limits.

The Problem the Plugin Solves

Codex is OpenAI's flagship agentic tool for development. The model can write code on its own, run it, check results, and iterate. However, Codex has two serious limitations: rising costs and strict usage limits. According to the plugin's author, with each update the limits get smaller and the price gets higher. Meanwhile, under the hood Codex runs on gpt-5.5 with a specific system prompt. This means that regular ChatGPT is the same model, and with proper task organization you can achieve similar results. The developer realized this and decided not to wait for OpenAI to ease the restrictions.

How Multi Pane Works

The plugin adds several independent panels to the ChatGPT.com interface, each working as a separate dialogue with gpt-5.5. Each panel is assigned its own role:

• the first dialogue writes code for the task
• the second checks the result and searches for errors
• the third holds the general project or task context
• the fourth accumulates a queue of next steps

While all dialogues work in parallel, the user can work on other tasks — no need to sit and wait for the model to finish its response. When the task is complete, the plugin sends a notification to Telegram. This approach is especially useful when refactoring a large project or working with several independent tasks simultaneously.

"One dialogue on the left writes code, on the right another checks the

result, a third holds the context, and meanwhile I could jot down the queue of next steps and go have tea," — the plugin's author on Habr.

Technical Details

The extension is implemented as an open-source Chrome plugin — the repository is available on GitHub under the name chatgpt-multi. No third-party APIs, additional keys, or special subscriptions are needed to use it: the plugin uses the same session as regular ChatGPT in the browser. Installation is standard: download the repository and load it as an unpacked extension through Chrome's developer mode.

Integration with Telegram for notifications is configured through the Telegram Bot API — any developer can handle this. Limitations remain the same as ChatGPT itself: several parallel requests can slow each other down on a free tier. The author calls the project experimental and warns of possible issues with interface updates, since the plugin works on top of the page's DOM elements.

Multi-Agent Approach as a Trend

Running multiple agents in parallel with different roles is one of the key architectural ideas in modern LLM development. This is how large systems are structured: one agent plans, another executes, a third verifies. OpenAI is developing Codex in this direction, Anthropic is building similar capabilities in Claude, Google — in Gemini.

The key advantage of such architecture is specialization without context mixing. When one LLM holds the entire task in a single dialogue, it loses the thread during long responses. Dividing by roles allows each dialogue to remain short and precise.

ChatGPT Multi Pane is a makeshift implementation of the same idea on top of the public interface: without the memory and tools of paid platforms, but the principle works.

What This Means

This is another example of how the community reproduces expensive paid features through available tools. Developers are increasingly breaking down OpenAI products into components and assembling alternatives from available means. If Codex doesn't fit the budget or the limits don't work — a multi-panel ChatGPT with Telegram notifications is a viable alternative for simple tasks.