Show HN: OpenMarkdown – A Markdown editor your coding agent edits with you

OpenMarkdown released a free, local-first Markdown editor built on a native Rust core that lets a user's existing coding agent read and edit the same plain .md files on disk, with the agent running in a terminal tab inside the sidebar. The editor ships no AI of its own, keeps every note as a plain .md file with no telemetry, and offers live preview, source and reading modes cycled with one key, plus an openmd CLI. The project targets macOS and Linux and is positioned around the claim that "the file is the memory" as agents change.

Ask, don’t hunt. Ask where something is. Your agent opens the right note and takes you to the heading — you read your own words, not a summary. A local-first Markdown editor built for you and your agent . An idea gives you about five seconds. OpenMarkdown takes less than one. A native Rust core: the window is there before you let go of the mouse. A real prompt shouldn’t live in a one-line box — point $EDITOR at OpenMarkdown, write it like a document, hand your agent the finished thing. No undo, no drafts, no half-sent prompts. No AI inside. That’s the point. It runs on the agent you already have. Local-first means every note stays a plain .md on your disk. The file is the memory. Agents change; your knowledge doesn’t. Your agent runs in a terminal tab right in the sidebar — the one you installed. It reads, finds and writes on the page you’re looking at. No AI ships inside OpenMarkdown. Terminal and intercom: macOS and Linux. Select a passage and ask. Your agent reads exactly what you selected and reworks it in place — nothing to copy into a chat box. $12/mo , fast, no SSO $9/mo , slow, has SSO $15/mo , fast, has SSO | Vendor | Price | Speed | SSO | |---|---|---|---| | Acme | $12/mo | fast | — | | Globex | $9/mo | slow | ✓ | | Initech | $15/mo | fast | ✓ | Ask for a draft under a heading. Only that section changes — the rest of your note stays exactly as you left it. Tick a box or fix a line. Your agent sees the change and picks up from there — no need to explain what you did. Type to your agent in the intercom; it replies in a line or two — never its working notes. Control without leaving the keyboard. Skip the file tree. Skip the menus. One key cycles all three — live preview, plain source, clean reading. Markers render as you type; your cursor enters an element and it snaps back to source. Every marker visible, syntax-coloured, one size. True plain text for commit messages and prompts. No cursor, no markers, just the page. Drafted with my agent — we’re both in plan.md : it writes, I tick, it reads the ticks back. plan.md : it writes, I tick, it reads the ticks back. - x map the current token flow - draft the migration steps - flag anything risky Byte-for-byte. OpenMarkdown never reflows, trims, or reformats your text — open and close, the file is unchanged. Delete moves files to the system Trash. Autosave when you pause, without nagging. Tabs, folder, and cursor come back after a crash. No telemetry, nothing phones home. Your agent reads the same file on the same disk — no third party in between. Standard Mac shortcuts — and ⌘P opens a palette for every command. Full list → https://openmarkdown.dev/docs/reference/shortcuts/ Full trilingual UI. Missing your language? Open a discussion. https://github.com/OpenMarkdown-dev/OpenMarkdown-releases/discussions openmd CLI Open files from your terminal. Install it in one click from Settings. It’s free, and it stays free. If it earns a place in your day, you can back it.