Cotext
Open beta · Free forever

Teach AI how you like it
by reacting, not writing.

Tired of telling Claude, ChatGPT, and Gemini the same thing every conversation? Cotext infers your preferences from how you react to AI responses - then applies them everywhere, automatically. No proxy, no second UI to learn.

Install for ChromeHow it works ↓
Coding · v12Active
Format

Answer first, no preamble. Skip filler openers like “great question!” or “certainly!”

Code

Show diffs, not whole files. Don't add comments unless they explain non-obvious why.

Honesty

Push back on bad ideas. Say “I don't know” when you don't.

42 signals · 12 versionsSee full profile →
Beyond the browser

Same profile, different surfaces. Cotext is also a CLI for your shell, an MCP server for Claude Code / Codex, and is open source end-to-end.

Terminal CLIMCP serverLocal-firstOpen source
~/project — zsh
$ cotext pull @alice/direct
✓ Wrote profile to ~/.claude/CLAUDE.md
25 rules · v47 · 3.1 KB
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How it works

React, learn, apply.

A small local AI watches how you react to AI responses, writes a personal profile from what it sees, and prepends it to every conversation — on every supported chatbot.

  1. 01

    React

    Like, dislike, or tag what's off as you chat. One click, no typing.

  2. 02

    Learn

    A local AI reads your reactions and writes concrete rules in plain English. Edit anything.

  3. 03

    Apply

    Your profile gets prepended to every conversation, automatically. The AI sees it before it answers.

Today
Every new conversation:
“Hey Claude - be concise, no emoji, push back when I'm wrong, TypeScript by default, file:line refs when pointing at code…”
Repeat for ChatGPT. Repeat for Gemini. Repeat tomorrow.
With Cotext
Your profile gets injected - silently - into every chat:
# Format
- Answer first, no preamble.
- Use file:line refs when pointing at code.
# Code
- TypeScript by default. No any.
- Show diffs, not whole files.
# Honesty
- Push back on bad ideas. “I don't know” OK.
25 rules, learned from 318 reactions. See full example →
Privacy

Stays on your machine

Most AI memory tools send your conversations to their servers. Cotext doesn't. Reactions, profiles, and the AI that learns from them all live on your computer.

Nothing leaves unless you choose to share it - and when you do, you get a link to a copy you control. Uninstall anytime; your preferences come with you.

What stays local
  • Your reactions and tags
  • Your synthesized profile
  • The AI model that learns from you
  • Your version history
Sharing a profile is opt-in and explicit. The shared copy contains the prompt - never your raw conversations.
Compatibility

One profile, every chatbot

Cotext runs on every supported site. Toggle per-domain if you want different behavior in different places.

ClaudeChatGPTGeminiGrokPerplexityMistralCopilot

Common questions

Things people ask before installing.

Will it slow my browser down?+
No noticeable impact during normal browsing. Synthesis runs locally when you react - typically once every few minutes - and takes 10–30 seconds on a modern laptop. The browser itself stays responsive throughout.
How is this different from ChatGPT memory or Claude projects?+
Those memories live inside one product. Cotext lives outside - learned from your reactions across all the AIs you use, then applied uniformly. And the data stays on your machine instead of their servers.
What does the local AI cost in disk and memory?+
About 3 GB of disk for the default model, and 2–4 GB of RAM while synthesis is running. It's idle the rest of the time. You can swap in a smaller model if disk is tight.
Can I edit my profile by hand?+
Yes. Open the extension's Prompt tab - you can rewrite, delete, or reorder anything. The synthesizer treats the prompt as the source of truth, so your edits stick.
What if I uninstall?+
Your profile lives in chrome.storage.local by default, and (optionally) mirrored to a folder you choose. Uninstalling clears the former; the folder copy is yours forever. You can also publish a snapshot to keep a permanent URL.
Mobile? Firefox? Safari?+
Not yet. Chrome and Chromium-based browsers today; Firefox and Safari ports are on the roadmap. Mobile comes after that.
Already using ChatGPT Memory, Claude Projects, or a CLAUDE.md? See how Cotext compares →

Get Cotext

Open source and ready to use today. Two paths work today — sign up for an account or build the extension yourself. The one-click Chrome install is in review.

cotext.io account

Sign up — ready now

Push profiles from your terminal, get a public @user/slug URL, fork and star public profiles, generate an API token for the CLI / MCP. No extension needed.

browser extension

Build it yourself — ready now

Clone the repo, run npm i && node build.mjs, load dist/ unpacked in Chrome. Same code that the store version will ship — the reaction-capture UX on every supported AI site.

View on GitHubBuild guide
chrome web store

Easier install — coming soon

Submission is in Google's review queue. Drop your email and we'll ping you the moment it lands — or use one of the paths above today.

The extension is in Chrome Web Store review. Drop your email and we'll send you the install link the day it's approved.