Xtension

Version 0.6.8 · Chrome · Edge · Firefox

Write better on X/Twitter,
with your own ChatGPT account.

Xtension adds a compact toolbar to the X/Twitter composer: correct, translate, reformulate, generate replies and create images — plus a clean PDF export for any article, tweet or thread. Requests go through your own authenticated ChatGPT/Codex session. No API key. No developer server. No account to create.

Download Xtension Read the source code
  • No OpenAI API key
  • No developer server
  • Signed Windows installer
  • Apache-2.0 open source

Everything Xtension does

Two independent halves: a PDF exporter that runs entirely in your browser, and a set of AI writing tools that run through your own ChatGPT/Codex account. Each one can be used without the other.

PDF export — fully local

Export from the ··· menu

A Download as PDF entry is added to the X/Twitter ··· menu of any article, tweet or thread.

Structure preserved

Headings, paragraphs, lists and quotes keep their formatting. Long threads are paginated so a post is never cut in half.

Smart thread detection

Contiguous posts from the same author are grouped together, and the export stops before replies from other accounts.

Images and quoted posts

Media images, avatars, card images and video preview thumbnails are embedded. Quoted tweets are included with their available content.

Generated in your browser

The PDF is built locally and saved through your browser's normal Save as dialog. Nothing is uploaded anywhere.

Clickable links preserved

Links stay clickable in the PDF, the source URL is added, and the exported account profile is linked at the end.

AI writing tools — through your ChatGPT account

Correction

Fixes grammar, spelling and syntax in your draft while keeping your voice. One click to undo.

Translation

Translates your draft into the output language you choose, preserving tone and meaning.

Reformulation

Rewrites your draft to be clearer or more impactful, within the character limit of a post.

Generate

Turn an instruction into a finished post. On an empty draft under a tweet, it writes a contextual reply instead. The writing style is driven by a prompt you control.

Reply suggestions

A panel proposes ready-to-post replies in several angles: human reaction, short impact, concrete argument, positive agreement, contextual humour, sharp angle, useful context, question — plus three prompts you can customize.

Image generation

Describe an image and attach it to your post. Square, landscape and portrait formats (1:1, 16:9, 9:16, 4:3, 3:4, 3:2, 2:3), style presets (photorealistic, illustration, infographic, 3D), framing and mood. The first image of the post can be used as a visual reference.

Undo / Redo

Every AI edit is reversible. Undo and redo arrows sit directly in the composer toolbar, so nothing is ever lost.

Model and reasoning control

Pick any Codex model available to your ChatGPT account and set the reasoning effort per request. Defaults: gpt-5.6-luna at maximum reasoning.

Five interface languages

The extension interface is available in English, French, German, Spanish and Japanese, selected automatically from your browser language.

How it works

A browser extension cannot spawn a desktop process, and it cannot safely hold an OAuth refresh token. So the AI features go through a small local connector that you install once on Windows.

  1. 1

    The extension

    Runs only on x.com and twitter.com. It reads the post you selected or the draft you typed, and nothing else.

  2. 2

    The local connector

    A small signed program listening on 127.0.0.1:47623, reachable only from your own machine. It starts the official Codex App Server in your Windows session, denies tool approvals and uses read-only ephemeral threads.

  3. 3

    Your ChatGPT account

    Codex reuses the ChatGPT sign-in that already exists on your computer. The request is sent to OpenAI under your own account, with the model and reasoning effort you selected. Xtension never asks for an API key.

The PDF export needs none of this — it works on its own, offline, as soon as the extension is installed.

Privacy & security

What Xtension does

  • Reads the visible text of the post, article, thread or draft you act on.
  • Fetches the public images of that content from pbs.twimg.com.
  • Sends that content to the local connector only when you click an AI action.
  • Stores your settings in the browser's extension storage, on your machine.

What Xtension never does

  • No data sent to a server owned by the developer.
  • No X/Twitter password, cookie or authentication token read.
  • No access to your private messages.
  • No browsing history, no analytics, no tracking, no ads.
  • No OpenAI API key requested or stored.

Verifiable security properties

  • Loopback only. The connector binds to 127.0.0.1. It is not reachable from your local network or from the internet.
  • Origin-restricted. Only browser-extension origins are accepted by the connector's CORS policy, and an optional shared token can be required.
  • No admin rights. The connector installs under your own user profile in %LOCALAPPDATA%. It never runs as SYSTEM.
  • Code-signed and timestamped. The installer is signed via Microsoft Trusted Signing. Verify it in Windows: right-click → Properties → Digital Signatures.
  • Checksums published. Every download below has its SHA-256 listed so you can verify the file you received.
  • No remote code. The extension ships all of its code in the package. It never downloads or evaluates code fetched at runtime.

Read the full privacy policy →

Download

Install the extension in your browser. Then, only if you want the AI features, install the connector on Windows.

1 · The browser extension

Chrome Brave · Vivaldi · Opera · v0.6.8 Download .zip Edge v0.6.8 Download .zip Firefox v0.6.8 Download .zip
How to install a .zip package

Chrome, Edge, Brave, Vivaldi, Opera

  1. Unzip the archive into a folder you keep.
  2. Open chrome://extensions (or edge://extensions).
  3. Enable Developer mode.
  4. Click Load unpacked and select the unzipped folder.

Firefox

  1. Open about:debugging#/runtime/this-firefox.
  2. Click Load Temporary Add-on and select the manifest.json inside the unzipped folder.

2 · The Codex connector (optional, Windows)

Only needed for the AI features. The PDF export works without it. Installs for the current user, no administrator rights required, and starts automatically when you sign in.

Download XtensionBridgeSetup.exe Windows · 82 MB · v0.6.8

Verify what you downloaded

On Windows, run Get-FileHash <file> -Algorithm SHA256 in PowerShell and compare with the value below.

File SHA-256
XtensionBridgeSetup.exe 898f17f85f330fcd3d7c2a1abeb3223c0f20995d196518a41f0549c7119434fe
xtension-chrome-v0.6.8.zip c3a358825285d4c40a408c72f837985c7bb5c8fe96f43212cdf62675a732565d
xtension-edge-v0.6.8.zip c3a358825285d4c40a408c72f837985c7bb5c8fe96f43212cdf62675a732565d
xtension-firefox-v0.6.8.zip f57932031f9bc7094d9d373f2e8cb8eda66ff9476e89c3ba5b0e29a587c007a3

Raw checksum file · version.json

Free and open source

An extension that reads what you write and a program that runs on your machine should be inspectable. The entire codebase is published on GitHub under the Apache License 2.0, so anyone can read exactly what Xtension does, review the network calls, check that the claims on this page hold — and use, modify or redistribute the code.

github.com/JoDevelop1/xtension Browse the code, open an issue

Licensed under the Apache License 2.0 — free to use, modify and redistribute, including commercially, with an explicit patent grant. Attribution and a copy of the licence are required.