Hi Product Hunt 👋 We're LGD Ventures, a tiny indie studio, and this is ChatCairn: a browser extension for people who live in AI chats.

The idea: your best thinking is scattered across ChatGPT, Claude, Gemini and Grok, and each one keeps it in its own app. ChatCairn gives you one library you own:

• save any chat in one click and search all four assistants at once

• export to PDF or Markdown, and turn highlights into notes and tasks

• 100% local: no account, no servers, nothing leaves your computer

New today, GPT Rescue: it turns the Custom GPTs and Gems you built into plain files: a folder per GPT with README.md, a SKILL.md, a paste-ready Claude Project file, actions as OpenAPI (secrets stripped), the knowledge files ChatGPT lets us download and the raw gpt.json, all in one ZIP. Gems come one at a time (instructions, default tool and file names).

Why now: OpenAI retires Custom GPTs on Dec 11, 2026, and Gems go read-only on Nov 17 for personal Google accounts. ChatGPT's own "Migrate to plugin" keeps a GPT working inside ChatGPT, but doesn't give you anything you can take to Claude or Gemini.

ChatCairn is free for 50 saved chats, and GPT Rescue is free with no Pro plan needed.

Pro is live now: $4.99/month or $69 lifetime, to keep saving past 50 chats, export your whole library as a ZIP and drop the export footer.

We'd love your feedback: what would make this your one place for AI chats?