# How I built thredly: a Chrome extension that never lets your AI context window die > Source: > Published: 2026-06-04 20:31:43+00:00 If you use ChatGPT, Claude, or DeepSeek heavily, you've hit this wall: the context window fills up, responses get worse, and you're forced to start a fresh chat — losing everything you built up. I kept running into this. So I built [thredly](https://thredly.io) — a Chrome extension that summarises your entire AI conversation and carries the context into a new thread automatically. Long AI sessions are where the real work happens. You've refined your prompts, established shared context, got the model thinking in a specific way. Then it degrades. You either push through with broken context or start over and lose momentum. It reads your current chat, generates a structured summary — goals, decisions, key context — and opens a new thread pre-loaded with it. The AI picks up exactly where you left off. Works on ChatGPT, Claude, and DeepSeek. Takes about 5 seconds. It's a Chrome extension built with vanilla JS. The main challenge was reliably extracting conversation structure across three different AI interfaces — each renders their chat DOM completely differently. For the summary itself, I'm calling the OpenAI API with a prompt engineered to preserve what actually matters: intent, decisions made, open questions, and established constraints. Still early days. If you've felt this pain, give it a try: [thredly.io](https://thredly.io) Happy to answer any questions on the build in the comments.