Short answer: AI tools write in Markdown, so their plans and answers are .md files, or text that can be saved as one. Open the file in a Markdown viewer to read it as a formatted page. On a Mac, nicemd does this for free: double-click the file, or select it in Finder and press Space, and the window keeps up while the AI is still rewriting the file. TextEdit opens the same files for free too, but shows the raw symbols.
Working with an AI produces a steady stream of Markdown. A plan before it starts. A summary when it finishes. CLAUDE.md and AGENTS.md that collect instructions over weeks (what each of those files is for). Most of it you need to read once, carefully, and never touch again.
Reading Claude Code plans
In plan mode, Claude Code writes its plan before it changes anything. Recent versions save each plan as a .md file in a hidden folder in your home directory, ~/.claude/plans/, with a generated name. To open that folder:
- In Finder, press
⇧⌘G(Go to Folder). - Type
~/.claude/plansand press Return. - Sort by Date Modified; the newest file is the current plan.
- Select it and press
Spaceto preview it, or double-click to open it in your Markdown viewer.
The folder can be changed in Claude Code's settings, and the location has moved between versions, so if it is empty, check your version's documentation. The simpler habit: ask Claude Code to save the plan to PLAN.md in the project folder. Then the plan sits next to your work, where you can find it, and it updates as the agent ticks items off. Codex, Cursor and other agents follow the same request.
Leave the plan open in nicemd while the agent works. Agents replace the file rather than editing it, which leaves many previews showing an old copy; nicemd follows the replacement and reloads (why previews go stale).
Reading Markdown from ChatGPT or Claude
Chat answers are Markdown too; the chat window just formats them for you. To keep an answer as a document:
- Click the Copy button under the answer. ChatGPT and Claude copy it as Markdown.
- Open TextEdit, choose Format → Make Plain Text (
⇧⌘T), and paste. - Save it with a name ending in
.md, such asanswer.md. If TextEdit offers to add.txt, choose to keep.md. - Double-click the file to read it formatted in your Markdown viewer.
If the chat tool offers a Download option for a document, and it includes Markdown, that skips the TextEdit step. Comfortable with Terminal? pbpaste > ~/Desktop/answer.md saves whatever you just copied. With the nicemd editor (free for 3 days, then a one-time unlock) you can also choose File → New and paste straight in.
From there, ⌘P → Save as PDF or Copy as HTML gets the answer into an email, a doc or a slide, formatted, without the stray asterisks.
The reader-shaped hole
Look at what the obvious options actually ask of you:
- TextEdit shows you the raw source. Pound signs, asterisks, pipe tables that no longer line up. It is the file, not the document.
- Xcode opens it — slowly — inside a project context you did not want, and has an unfortunate habit of installing itself as the default app for
.md. - VS Code or Cursor render it well, but you are opening a code editor to read a page of prose, and the file lands in a workspace as a tab you now have to close. There are lighter routes — see reading Markdown without VS Code.
- Obsidian is excellent and wants a vault. Opening one loose file that lives in a repo, outside any vault, has been an open request for years.
- The browser works if you convert first, which means you are now generating and cleaning up HTML files.
None of these are bad tools. They are all answering a different question. The question here is narrow: this file already exists, something else is responsible for writing it, and you want to read it now.
What actually matters for agent output
Reading agent-written Markdown has a different shape from reading your own notes, and the differences point at specific features rather than general polish.
It is long
Agents are verbose. A plan for a moderate refactor runs to several screens of nested headings. The single most useful feature for this kind of document is not typography, it is an outline — a live table of contents you can use to jump to the section you actually care about and to see the shape of the argument before reading it. Skimming structure first is how you read a long generated document quickly.
It changes while you are looking at it
The agent is still working. It will rewrite the plan as it goes. A reader that shows you a snapshot from thirty seconds ago is worse than useless, because you will act on it. This is harder than it sounds, and most tools get it wrong for a specific technical reason — agents replace files rather than editing them, which breaks naive file watching.
It is full of code, diagrams and math
Agent output leans on fenced code blocks, Mermaid diagrams for architecture and flow, tables for comparisons, and occasionally LaTeX. A reader that renders the prose but drops a Mermaid block on the floor — or worse, shows you its raw source — has failed at the part of the document carrying the most information.
You are not the author
This is the one that shapes everything else. You did not write this file and you may not want to change it. A tool that opens it in edit mode invites accidental keystrokes into a file your agent is also writing to, which is a good way to lose work or create a conflict. Reading should be the default state, and editing should be something you ask for.
Stop Xcode from claiming your .md files
If double-clicking a Markdown file launches Xcode, that is a file association, and it is worth fixing once properly. The usual right-click route does not stick — people set it, reboot, and find Xcode back in charge.
- Select any
.mdfile in Finder and press ⌘I to open Get Info. - Expand Open with and choose the app you want.
- Click Change All… and confirm.
The last step is the one that matters. Choosing an app in the dropdown without clicking Change All only affects that single file, which is why the setting appears to revert. Change All rewrites the association for every .md file on the system.
Reading without opening anything
For a lot of agent output you do not even want a window. You want to look at the file in Finder, confirm it says what you expected, and move on. That is what Quick Look is for, and on a stock Mac it shows Markdown as plain text — see previewing agent output in Finder for how to get a rendered preview instead.
Where nicemd fits
nicemd is a Markdown viewer and editor for Mac. It opens a single .md file, rendered, with no project and no vault. It has an outline sidebar (⌃⌘S) for moving through long documents, renders GitHub Flavored Markdown along with Mermaid diagrams, KaTeX math and syntax-highlighted code, all bundled so none of it needs a network connection, and reloads when another tool rewrites the file underneath it.
Reading is the default. Reading, Quick Look, Save as PDF and Copy as HTML are free; edit mode, split view and export to HTML and Word are a one-time unlock, with a free 3-day trial. If the agent wrote you a plan with a task list in it, you can also tick items off directly in the rendered view and have nicemd write them back to the file. Get it on the Mac App Store.
Questions
Where does Claude Code save plans?
Recent versions save them as .md files in ~/.claude/plans/, a hidden folder in your home directory. Use ⇧⌘G in Finder to get there, or ask Claude Code to write the plan to PLAN.md in your project instead.
Why does my AI's file show # and ** symbols?
That is Markdown, shown as raw text. The app you opened it with does not format Markdown. Open it in a Markdown viewer, or see how to open a .md file on a Mac.
Can I read these files without VS Code?
Yes. Quick Look with a Markdown extension, or a Markdown viewer, shows them formatted without a code editor. See Markdown without VS Code.
How do I send an AI-written plan to someone who does not use Markdown?
Open it in a viewer and use ⌘P → Save as PDF, or Copy as HTML and paste into an email or Google Docs. nicemd can also export to Word with the unlock.