Write in your own voice.
GeodeQuill teaches your AI app how you write. Give it a few things you wrote, and it writes or rewrites anything in your voice, in the tone you pick.
What it does
Learns your voice
From emails, posts or letters you wrote. Add transcripts of you talking, and it learns how you sound out loud too. Or make your voice file yourself on the Make my voice page, which runs in your browser.
Keeps voices and tones
A work voice, a casual voice, a character, or one of five built-in authors: Twain, Austen, Dickens, Lincoln and Wilde. Pick a tone each time: formal, casual, friendly, intimate and nine more. Ask for writing that is easier to read and it uses everyday words and shorter sentences, keeps every fact, and on a check tells you the reading level before and after.
Reviews every draft
Against your own habits, and against the patterns that make text read as machine-written, then fixes what's off. Then it offers to measure the draft exactly with its checker; say yes and you see your app run it. You can also paste any draft into the check page, which runs in your browser.
What it won't do
- Promise to get past AI detectors. They guess, and they're often wrong. It never gives a score.
- Make things up about you. It is built not to invent memories, quotes, numbers or opinions, and leaves a [bracketed note] for details only you know. Read the draft before you send it: no check catches everything.
- Put words in a real person's mouth. A famous person's voice is always labelled "in the style of". It only goes looking for someone's writing when that writing is free of copyright.
- Use tricks. No invisible characters, no planted typos.
Looking for an AI humanizer?
Plenty of tools promise to "humanize" AI text so detectors miss it. GeodeQuill doesn't make that promise, because detectors guess and nobody can guarantee their verdict. What it does is make the writing sound like you: your rhythm, your words, your habits. It also takes out the patterns that make text read as machine-written.
Where it works
ChatGPT, on plans with skills
Add it on chatgpt.com if your plan includes skills. The Free and Go plans don't, and OpenAI's help pages disagree about the rest. Whether the ChatGPT phone and desktop apps then use it isn't confirmed.
Claude, on the web and the desktop app
Every Claude plan, including Free. The phone app can't add skills: add it once from a computer, on the Claude website or in the desktop app, and the phone app uses it from then on.
Other apps that read skills
Codex, GitHub Copilot, Gemini CLI, Cursor, VS Code and more. Apps that take MCP connectors work too.
Any language
It writes in any language. It looks for machine-writing phrases in English, Chinese (simplified and traditional) and Spanish. In every language it checks punctuation, layout and paragraph rhythm, and sentence rhythm wherever the writing marks where sentences end (Thai, Lao and Tibetan don't). For a language with no phrase list, its report says when the phrase check didn't run. Reading level is measured only for writing in the Latin alphabet, such as English or Spanish.
GeodeQuill runs inside your AI app. This page can't do the writing itself, because that would need a paid AI server, and we don't run one.
Install it
Pick the app you use. Each one takes a couple of minutes.
ChatGPT
- Download the skill file.
- On chatgpt.com, in the sidebar, select Plugins, then the Skills tab.
- Select Create, then Upload from your computer, and choose the file.
- Wait for ChatGPT to check it. Then start a chat and say "Set up my voice."
No Skills tab, or a message that skills aren't available for this account? Your plan doesn't have skills yet. OpenAI's help pages disagree on which plans do: one names the business plans, another says every paid plan except Free and Go.
Claude
- Download the skill file.
- In Claude, go to Customize, then Skills.
- Select +, then Create skill, then Upload a skill, and choose the file.
- Start a chat and say "Set up my voice."
Skills need code execution turned on in Claude's settings.
In the Claude desktop app you can install the plugin file instead. In Claude Code, type /plugin marketplace add GeodeForge/geodequill, then /plugin install geodequill@geodeforge.
Codex, Copilot, Gemini CLI, Cursor and others
- Download the skill file.
- Unzip it into your app's skills folder. Your app's help pages say where that folder is.
- Say "Set up my voice."
Apps that take MCP connectors
- Download the connector file and unzip it.
- Follow the README inside. You need Python 3.10 or later.
ChatGPT doesn't take this kind of connector. Use the skill file there.
AI apps sometimes answer a short request themselves without opening GeodeQuill. Anthropic's own guide for people who write skills says Claude tends to skip a skill on a short, simple request, even when the request matches the skill's description exactly. To make sure it's used, start with "Use GeodeQuill to…", for example "Use GeodeQuill to write a thank-you note like Jane Austen."
Already using GeodeQuill? Your saved voices are kept. Add the new file the same way you added the first one; if your app says the skill already exists, delete the old one first. In Claude Code, run claude plugin marketplace update geodeforge and then claude plugin update geodequill@geodeforge in a terminal, then restart Claude Code. To hear about new versions, watch GeodeQuill's releases on GitHub (select Watch, then Custom, then Releases). In Claude Code, updates can arrive on their own: type /plugin, open Marketplaces, pick geodeforge, and choose Enable auto-update.
Download
Free, open source, and nothing to sign up for.
We invite you to double-check our work
This page carries no analytics, no cookies and no third-party requests. Open your browser's developer tools, switch to the Network tab and reload. You'll see only this site's own files.
GeodeQuill adds no connection of its own. Its checker is one Python file that reads text and prints numbers. What you write still goes to the company whose AI app you use, under that company's terms.
The whole source is on GitHub. Read it, run the tests, fork it.
Found a bug, or a claim that doesn't hold up? Tell us. An example helps enormously, though we understand if yours is too private to share: quill@geodeforge.com
That's the difference between a privacy policy and a fact.