Desktop Extensions (DXT): Giving AI access to Notes, Tabs, and Texts
Test driving Anthropic's new format for installing local MCP servers
On Thursday, Anthropic (creators of Claude, and of the original MCP spec) quietly launched something powerful: “Desktop Extensions” or DXT. DXT is a new way to package and install local MCP servers (basically, giving Claude new powers to interact with your local files and apps) in just a few clicks.
If you read last week’s post on MCP’s branding troubles, this only worsens the lingo confusion: MCP Servers, which Anthropic used to just call “Integrations” are now sometimes called “Extensions,” depending on where and how they’re installed:
However, if we look past the terminology, there’s good news: DXT is a big usability upgrade, and unlocks some cool use cases for non-software-engineer audiences.
Let’s look at an example of why DXT matters and what it enables, focusing on something broadly relatable: meal planning!
Meal Planning with the Notes Desktop Extension (DXT)
One of the best things about Desktop Extensions is that they run locally. That means they can interact with your Mac files and apps (like Notes, Messages, and Downloads) without needing to upload anything to the cloud.
As part of the launch, Anthropic included one-click installs for a few Extensions that work directly with these apps apps:
So, I tried the new Notes extension to help with a real-life task: meal planning with my partner.
We’ve been using Claude to do quite a bit of ‘vibe meal planning,’ where AI helps us brainstorm meals and grocery lists, then we copy-paste the results into a shared note. All our past plans live in that note now.
With the new Notes extension, I asked Claude to look at that note and use it to suggest meals for the week. It worked beautifully:
(It’s true: granola bars, half-and-half, and bananas are household staples).
Claude could even update the grocery list automatically—no manual copy/pasting needed. This was a small but meaningful upgrade to a workflow I already used, because Claude now has context from Notes, which was previously a ‘walled garden.’ Local MCPs enable interoperability, even with Apple apps.
Going Deeper: Installing the Open Nutrition MCP (or, why Desktop Extensions matter)
Encouraged by how easy that was, I then tried another MCP server: ‘Open Nutrition’ MCP server. This MCP server analyzes the health content of meals, so I was curious to get a nutritional assessment for my vibe meal planning.
But unlike the Notes extension, Open Nutrition doesn’t support the new, easy-to-use DXT format.
Installing it meant:
Cloning a GitHub repo (an ‘implicit step’ not written in the instructions)
Installing some stuff in your computer’s terminal/command line
Finding the correct paths to specific folders on your desktop
Managing Node versions
Even for someone familiar with MCP servers, it was frustrating. A missing version update and a single stray comma tripped me up for quite a bit:
Eventually, though, I did get there, and it was cool to see the analysis (although the calorie estimates are quite low; I suspect I would get better results if I asked for full recipes first):
Most importantly, the contrast was clear: the DXT experience was easy, the other was a technical headache.
Why DXT Matters
That’s the whole point of DXT. It turns something niche and technical into something nearly plug-and-play.
Instead of editing JSON files or battling version conflicts, DXT lets developers package a local MCP server into a single file. Users can drag, drop, and click to install:
You can then immediately see info about the MCP server and install it, with no need to battle through technical details:
This opens up local AI tooling to a much broader audience. And more accessibility means more experimentation, more use cases, and more value for users.
DXT: Looking forward
While I still think that remote (cloud-based) MCP servers will be the dominant mechanism of the future, there are some things (like, manipulate Apple Notes) that remote MCP servers just can’t do.
So, despite the awkward naming and some rough edges, I’m very excited about DXT. It simplifies one of the hardest parts of using AI locally — setup — which is a win for everyone. I hope more MCP creators will add support soon, so users can discover how easy this is.
And in the meantime, I’m looking forward to easier meal planning!
Appendix: Why can Local MCP Servers do more?
You can think of Desktop Extensions as a simpler way to install local MCP servers—tools that run directly on your computer rather than in the cloud.
Because you download the code for local MCP servers, and those servers run directly on your machine, your operating system trusts them implicitly. That trust unlocks capabilities that remote servers (even secure ones) simply don’t get. Local MCPs can read files, control desktop apps, and run scripts—things that would never be allowed from a cloud service.
When Anthropic launched DXT, they included four pre-built Desktop Extensions that take advantage of this local access and trust (at least for Mac users):
Filesystem
iMessage (AppleScript)
Chrome (AppleScript)
Notes (AppleScript)
Why AppleScript? Because Apple doesn’t make it easy for third-party apps to access its ecosystem. Unlike platforms that expose APIs, macOS often relies on a much older tool: AppleScript, a quirky but powerful scripting language that’s been around since the 1990s. It’s not widely used because it’s obscure and often annoying to write.
But when Claude uses AppleScript on your behalf, you don’t have to write a line of it. You just describe what you want in natural language—and the local server handles the automation.
That’s where local MCP servers really shine. They can:
Read/write files on your machine
Automate apps like Notes, Chrome, or Messages using AppleScript
Do things that no remote service is allowed to do
For example:
“Text [Number] a haiku using Claude”
“Summarize my open Chrome tabs and save to a note”
“Send my weekend plans from Notes to [Name] with formatting”
Cloud-based tools can't do these things because they can’t access your files or apps directly. Local servers can, and Desktop Extensions make it much easier to use that power.