Installing the ChatGPT desktop app gives you a few extras that aren't available through the web portal, including the ability to run prompts that query your local files, emails, and screenshots. Now, with the macOS client, those additional features extend to your iMessages, too: There's now an Apple Messages plug-in available.The idea of giving ChatGPT access to your chats is something a lot of users aren't ever going to countenance—"good luck with that spy software" is one typical response on Reddit—but we know that plenty of users are already asking AI for help in composing and interpreting messages. This just makes that process more streamlined. (Claude has an Apple Messages plug-in too, for what it's worth.)As OpenAI confirmed to TechCrunch, the plug-in does all its processing on your Mac, and doesn't send anything about your chats back to servers in the cloud—these Messages conversations won't appear in your ChatGPT apps on the web or on mobile. In addition, the ChatGPT desktop app doesn't build a full index of your text messages.This is something that's available for all ChatGPT users who have a Mac: To get started, download and install the desktop app for macOS, then open the Plugins tab, search for "messages," and click Install next to the Apple Messages entry. You can then use natural language in your prompts to invoke the plug-in ("send a message to..."), use the @Messages mention, or select Messages from the plug-in list in the prompt box (click the + icon to find it). You'll need to give the plug-in specific permission to operate. Credit: Lifehacker Once you've set it up, ChatGPT can then do just about anything you can imagine with your messages, starting with the basics: It'll send messages for you, for example, and even compose them if you're stuck for inspiration. You just have to name the contact, so something like "message Steve telling him I'm sorry I can't come to his dinner party in a polite way" will do exactly that.When I tried this, ChatGPT whipped up a suitably friendly message, with the right blend of thank yous, sorrys, and hopes for a lovely evening. When sending messages, you get the option to review what's being sent and approve it before it goes out—you can approve messages each time, or have them sent automatically in the conversations you select.Then there's everything the AI is able to do with your message history. You can use prompts like "who's messaged me the most this week?" or "is there anything I need to follow up on in my conversations?" and have ChatGPT take a look.I tried getting ChatGPT to dig back into my message history for details of event arrangements and deliveries, and it picked out the right information each time. I also got it to look back over text messages from my phone carrier to see if my bill had gone up over time, which it had: The AI gave me the exact increase, and the percentage increase, together with the relevant dates. ChatGPT can send messages to your contacts, with your approval. Credit: Lifehacker Conversations can continue based on whatever you find as well, so if you discover there's a chat thread with an invite that you haven't responded to, ChatGPT can sort that for you—and may even draft a suitable reply you can approve with a couple of clicks, depending on the context.It's in this message history retrieval and analysis where the ChatGPT plug-in seems most useful to me. I'm reluctant to start farming out message composing and sending duties to AI—it seems rude, first and foremost, not to mention bad for my brain—but searching through reams of text is something that AI does well, and could genuinely end up saving me some time.If you're prepared to trust ChatGPT with access to your Apple Messages chat list (and that's a big "if") then it's another database for the AI to mine and analyze. As with a lot of these other plug-ins, like Claude and Gmail, it's a question of where you're going to draw the line between privacy and convenience.And there are certainly risks to watch out for: I can see this being yet another way that people become over-reliant on AI and its "thoughts." If you want ChatGPT to assess someone's mood over time based on their chat history, or compose a message that gives you the best chance of rekindling a relationship, or write a text getting you out of work based on a fake excuse that sounds genuine, ChatGPT will do it. That's where the tech veers beyond the useful and straight into the uncomfortable.