OpenMarkdown is a local-first Markdown editor for macOS that keeps notes as .md files and supports agent collaboration via CLI, MCP server, and Claude Code plugin.

OpenMarkdown

Overview

OpenMarkdown is a local-first Markdown editor for macOS that keeps your notes as plain .md files on disk. The product is designed around quick startup, keyboard-driven editing, and a file-based workflow that does not rely on a database or cloud account.

It also adds agent-friendly collaboration through an openmd CLI, an MCP server, and a Claude Code plugin. That lets an external agent open the same file, jump to headings, read sections, and write content in place while the app stays on the user's machine and renders the file directly.

Features

Fast local editor startup

Opens and renders Markdown files quickly enough that the app window appears before a heavier editor’s loading screens. The homepage positions speed as a core part of the workflow rather than a separate mode.

Plain-file, local-first storage

Keeps notes as plain .md files on disk with no database or file lock-in. The site says open and close leave the file unchanged, with autosave after pauses and crash recovery for tabs, folders, and cursor position.

Agent collaboration through MCP

Works with an external agent rather than embedding AI inside the app. The guide and install page describe MCP connectivity plus a Claude Code plugin, with tools for opening files, revealing headings, reading sections, writing sections, waiting for changes, and running commands.

Shared-file editing workflow

Lets the agent work in the same file the user is viewing, including opening the right note, jumping to a heading, and editing selected text or sections in place. The install runbook is built around co-editing a live note with the agent.

Three-view Markdown rendering

Offers three views for the same Markdown file: live preview, source, and reading. The guide says a single control cycles between them, and source mode keeps markers visible for prompts and commit messages.

Keyboard-first control

Includes a command palette and keyboard-driven navigation. The guide documents standard Mac shortcuts, ⌘P for commands and files, heading jumps, find-and-replace, tab switching, and zoom controls.

Use cases

  • Local note-taking

    Write and save notes in plain Markdown without moving content into a database or hosted workspace. This fits users who want files they can keep, back up, and open elsewhere.

  • Agent-assisted editing

    Collaborate with an agent on the same document, with the agent opening files, reading sections, and writing changes directly into the note. The install flow is built around that shared-file model.

  • Terminal-driven navigation

    Use the editor from the terminal through openmd to open files, reveal headings, check what is already open, or wait for a file change. The guide treats the CLI as part of the normal workflow, not a separate integration.

  • Plain-text drafting

    Draft prompts, commit messages, or other plain-text content in source mode, where Markdown markers stay visible and text is not reformatted. The guide calls out source mode as useful for prompts and commit messages.

  • Reading and previewing documents

    Open a document in live preview or reading mode when you want a rendered view rather than raw Markdown. The product cycles between the three views for the same file.

Pros and Cons

Pros

  • Keeps content in plain Markdown files, which makes notes portable and avoids vendor lock-in.
  • Supports local-first workflows with no account, cloud dependency, or telemetry mentioned on the site.
  • Provides multiple ways for agents and terminal tools to interact with the same file, including MCP and a CLI.
  • Documents a keyboard-centric workflow with command palette access and standard shortcuts.
  • Supports three presentation modes for the same document: live preview, source, and reading.

Cons

  • Windows and Linux are listed as coming soon, so the current download is not cross-platform.
  • The public site does not show pricing details, so the commercial model is not clear from the available pages.
  • Agent setup depends on the desktop app being installed and the openmd CLI being enabled before the agent can connect.

FAQ

What agents or clients can connect to OpenMarkdown?

OpenMarkdown is a local desktop Markdown editor, and the guide and install page describe support for Claude Code, Codex, Gemini CLI, opencode, and any MCP client through the openmd MCP server.

How do you set it up?

The install page says you first install the desktop app, then turn on the openmd command line tool in Settings. After that, you connect your agent by pointing it at the openmd MCP server or by using the Claude Code plugin flow.

Does OpenMarkdown store notes in a database?

No. The site says OpenMarkdown uses plain .md files on disk, and the file stays the source of truth while the app renders and edits it.

Is there a command-line workflow?

The site says OpenMarkdown can open files from the terminal with the openmd CLI, and the guide documents commands such as openmd notes.md, openmd reveal, openmd status, and openmd mcp.

What platforms are supported today?

The homepage says Windows and Linux are coming soon, while the current download section lists macOS with Apple Silicon and Intel support.

Quick Facts

Category
Markdown editor
Platform
macOS now; Windows and Linux coming soon
Workflow
Local-first plain .md files with CLI and MCP agent access
Primary users
People editing Markdown and users collaborating with external agents
Source domain
openmarkdown.dev
Pricing
Not stated on the available pages