Let Claude and ChatGPT read your folder — MCP basics and what works today
What MCP is, what AGENTS.md is, and how the Claude and ChatGPT desktop apps read a folder on your computer today. All from official docs, every card links to the original.
Two words first
How to use this canvas
- Every card is yours to edit.
- Checked to-dos are saved back to the file.
- In Finder, the whole canvas is just a folder.
What MCP is
- Official definition: an open-source standard that connects AI apps to outside data, tools and workflows, such as local files, databases and search.
- The official analogy is a "USB-C port for AI applications": one standard plug, so a tool built once works with many AI apps.
- The official list of supporting AI assistants includes Claude and ChatGPT.
- What it means for you: AI can see more and act for you, so you decide what to connect and how much access to give (see Group 4).
- Source: MCP official docs (official) https://modelcontextprotocol.io/docs/getting-started/intro
What AGENTS.md is
- A plain text file at the top of a folder, like a README written for AI: what the folder is for, how files are organized, what not to touch.
- No required format; ordinary headings and paragraphs are fine.
- The site says it's used by over 60,000 open-source projects and stewarded by the Agentic AI Foundation under the Linux Foundation.
- Source: AGENTS.md site (official) https://agents.md/
Two ways that work today (no code) / How put·here fits
Claude: connect a local folder in Cowork
- In the Claude desktop app, pick a local folder and Claude can read and write the files in it, with no uploading or downloading.
- Plans: Cowork is for paid plans only (Pro, Max, Team, Enterprise).
- For local files, the desktop app has to be open and connected.
- Before permanently deleting a file, Claude asks you first.
- When a folder comes in through a link, the desktop app always shows a confirmation dialog.
- Sources: Claude Help Center, Get started with Cowork (official, page marked "Updated this week") https://support.claude.com/en/articles/13345190-get-started-with-claude-cowork · Claude Help Center, Open Claude Desktop with a link (official) https://support.claude.com/en/articles/14729294-open-claude-desktop-with-a-link
ChatGPT: create a local project in the desktop app
- In the ChatGPT desktop app, open the project menu → Edit project → Add folder.
- Official docs: ChatGPT can read and change files in every attached folder; local commands are limited by a sandbox.
- You can attach several folders; new chats start in the primary folder, and Make primary changes it.
- This page doesn't say which plans include local projects, and another official help page didn't load today, so check OpenAI's help center for plan details.
- Source: ChatGPT docs, Projects (official) https://learn.chatgpt.com/docs/projects
One opening line that works in both
Start the chat with: "First read AGENTS.md at the top of this folder and follow it, no need to repeat the rules. Then tell me in two sentences what's in here,…
Your put·here library is a normal folder
Each card is a file in the folder, so both ways above work as they are.
Three things to think about first (safety)
Give AI only the folder it needs
Both Cowork and ChatGPT local projects can change files. Don't attach your whole home folder; one dedicated folder is enough.
Read its plan before letting it run
Claude's permission modes range from asking every step to skipping checks; the official page advises caution with skipping. Review its plan, especially with…
Install local MCP tools only from sources you trust
MCP's official security guide warns that a local MCP tool runs with your privileges; an untrusted one can run arbitrary commands or take your data.
Three things to try this week (drawn from the sources above) / Sources
Make a folder just for AI
Create a new folder with only the material you want AI to see. (From: Give AI only the folder it needs)
Write a one-page AGENTS.md
Three short sections: what's in here, how files are named, what not to touch. (From: What AGENTS.md is)
Try the opening line
Attach the folder in the Claude or ChatGPT desktop app, paste the opening line, and check whether its summary is right. (From: Claude: connect a local folder…
Sources
| # | Source | Type | Date | Checked |
|---|---|---|---|---|
| 1 | MCP docs: What is MCP | Official | live docs | 2026-10-29 |
| 2 | AGENTS.md site | Official | live page | 2026-10-29 |
| 3 | Claude Help: Get started with Cowork | Official | "Updated this week" | 2026-10-29 |
| 4 | Claude Help: Open Claude Desktop with a link | Official | live docs | 2026-10-29 |
| 5 | ChatGPT docs: Projects | Official | live docs | 2026-10-29 |
| 6 | MCP Security Best Practices | Official | 2026-07-28 version | 2026-10-29 |
| 7 | OpenAI Help: ChatGPT Work and Codex | Official | — | didn't load on 2026-10-29; not cited |
