Kempt
In short
Uploading sends a copy of one file.To work with files that stay on your Mac, connect a local tool: Claude Desktop’s Filesystem extension, Claude Code, or the ChatGPT desktop app’s Work mode and Codex, each limited to folders you choose. What they read still goes to the provider. They see raw files, not which payslip is your latest; Kempt adds that over MCP, with your yes for each paper.
Without any app
Claude Desktop
Settings › Desktop app › Extensions (Manage) › Browse extensions, then install Filesystem (marked Anthropic verified). Give it one folder, not your home folder: it can read, write, move and search files there. Extensions run in Claude Desktop and Claude Code, not on the web.
Claude Code
In Terminal, open the folder and run claude. It reads files in that folder when a task needs them and sends what it reads to Anthropic; transcripts stay on your Mac for 30 days by default.
ChatGPT desktop app and Codex
In the ChatGPT desktop app, Work can open a local folder and use only the files a task needs; OpenAI notes that messages and task context may be stored in the cloud. Codex (brew install --cask codex) runs in a sandbox, edits inside the working folder and asks before going further.
ChatGPT on the web
Only uploads. Its developer mode connects to remote MCP servers over HTTPS, not to programs on your Mac.
Keep access small
Make a folder for what the AI may see. Anthropic gives the same advice for Cowork: it can change and delete files in the folders you connect.
| Method | What it reaches | What leaves the Mac | Good for |
|---|---|---|---|
| Upload in the chat | The one file | The whole file | A single question |
| Claude Desktop + Filesystem | Folders you allow, read and write | What Claude reads | Working across a project folder |
| Claude Code | The folder you run it in | What it reads | People at ease in Terminal |
| ChatGPT desktop (Work) or Codex | The folder you open | What it reads, plus task context | ChatGPT users |
| Kempt over MCP (Claude Code) | Papers Kempt has read, read-only | Only what you approve, private numbers hidden | Paperwork |
With Kempt
- 1
Your papers, understood
Kempt already knows each paper’s kind, date and issuer, so Claude Code can ask for “the last three payslips” instead of reading folders. Seven read-only tools: search_papers, read_paper, ask_papers, my_facts, prepare_papers, prepare_reply, collect_shared_papers.
- 2
You decide in the notch
Settings › Intelligence › AI apps: “AI apps can see” is Off by default, then file names and locations, then contents. Reading a paper needs your yes in the notch, valid for one hour per session. Social security numbers and IBANs arrive hidden unless you turn on “Show private numbers to AI apps”.
- 3
Prepared on your Mac
With prepare_reply, Claude Code hands Kempt a request; Kempt prepares it on your Mac and Claude Code only gets the status, unless you review the copies and share them. Copy Setup gives the one-line command for Claude Code. In the edition from usekempt.app only; Codex and other MCP apps can connect but only Claude Code is tested.
$27 once, 14 days freeRuns on every Apple silicon MacA question? Ask a person
Questions people ask
Can ChatGPT read files on my Mac?
The ChatGPT desktop app’s Work mode and Codex can open a local folder you choose. ChatGPT on the web can only read files you upload.
Is Claude’s Filesystem extension safe?
It does what you allow: reading, writing and moving files in the folders you give it. Give it a dedicated folder and keep private papers out.
What is MCP?
The Model Context Protocol is an open standard for connecting AI apps to other programs and data. An app like Kempt runs an MCP server; Claude Code, Codex and other clients connect to it.
Does Kempt work with ChatGPT?
Kempt’s MCP server runs on your Mac. ChatGPT on the web only connects to remote servers, so today Kempt is tested with Claude Code; Codex can use the setup Kempt copies, untested.
How do I give Claude Desktop access to a folder?
Install the Filesystem extension (Settings › Desktop app › Extensions) and give it the folder you want Claude to use.
Is MCP safe?
An MCP server can do what it was built to do. Prefer read-only servers, folders you chose, and apps that ask before sharing; Kempt’s tools are read-only and need your yes in the notch.
Can Claude Code read PDFs on my Mac?
It can open files in the folder you run it in. Scans without a text layer are harder; Kempt reads them with text recognition first.
Can Claude Desktop access local files?
Yes, once you install the Filesystem extension and give it a folder. It can then read, write, move and search files in that folder, and what it reads goes to Anthropic.
Does Claude read all my files?
No. Claude only sees what you upload or the folders you connect; Claude Code sees the folder you run it in.
Can Claude Code read all my files?
It can open files in the folder you start it in and below. Start it in a project folder, not your home folder.
Is it safer to connect my files through MCP than to upload them?
It can be: a read-only server you approve shares only what a task needs, while an upload sends the whole file. Kempt’s MCP server adds your yes in the notch and hides private numbers.