# Mash

> Mash is a free, open-source macOS application that arrives as a complete
> agentic coding workspace: Herdr for workspaces and agents, Pi for the coding,
> and the Mash skills that teach both, already wired together.

Canonical URL: https://letsma.sh/

## What Mash is

Mash arrives as one Mac app with the stack already wired together: Herdr for
workspaces and agents, Pi for the coding, and the Mash skills that teach both
your workflow. Everything runs from the keyboard, and the code stays visible and
editable by hand.

- **One workspace per task**, each with its own tabs, terminals, and agent, so a
  second and third agent never bury the first.
- **The code stays yours.** The agent works in a pane beside the file, not
  behind a chat window. Open the buffer, make the change yourself, and the agent
  picks up from what is on disk.
- **Speed still ends in a human review.** Agents propose and you decide what
  lands, hunk by hunk, before anything is committed.
- **Keyboard first.** Workspaces, tabs, panes, agents, search, and review all
  have keys, and the command palette holds the rest.

## Capabilities

- Workspaces and worktrees, one task each
- A coding agent in every workspace
- Editor and agent in the same tab
- Review tabs, with the diff beside the agent
- Command palette and fuzzy file finder
- Session search across every agent conversation
- Source control, annotations, and pane splits
- Plugin manager and detachable sessions
- macOS on Apple silicon

## Install and availability

- Platform: macOS on Apple silicon. No Intel build.
- Distribution: one signed and notarized DMG.
- Price: free, open source under GPL-3.0-or-later. No account, subscription, or in-app
  purchase.
- Current state: no public release yet. The first build will be published at https://github.com/LuisAlejandro/mash/releases with release notes, and https://letsma.sh/ offers the download once a compatible DMG exists.
- Source: https://github.com/LuisAlejandro/mash

## Captures

Each image below is a real state from the application.

- [A Mash workspace](https://letsma.sh/assets/mash/setup.png) — The agent session list, file explorer, editor, and agent notes in one Mash workspace
- [Workspace picker](https://letsma.sh/assets/mash/workspaces.png) — Mash's workspace picker listing four workspaces with their paths
- [File finder](https://letsma.sh/assets/mash/human-control.png) — Mash's file finder listing repository files with a source preview
- [Review tab](https://letsma.sh/assets/mash/review.png) — Uncommitted changes, the working diff, branches, and recent commits in Mash's review tab
- [Command palette](https://letsma.sh/assets/mash/keyboard.png) — Mash's command palette with the key combination printed beside each command
- [A tour of Mash](https://letsma.sh/assets/mash/hero-film.mp4) — the command palette,
  workspace picker, file finder, and review tab, recorded from the app (24s).

## Questions

### What is Mash?

Mash is a single macOS application that bundles a complete agentic coding environment: Herdr for workspaces, tabs, and agents; Pi for the coding; and the Mash skills that teach both. It arrives already configured rather than asking you to assemble those tools yourself.

### Is Mash free?

Yes. Mash is free and open source under the GPL-3.0-or-later license, with no account, subscription, or in-app purchase. You download one disk image, drag the app to Applications, and the first launch sets up the rest.

### Which Macs does Mash run on?

Mash is built for macOS on Apple silicon. It ships as one signed and notarized DMG; there is no Intel build, and nothing to install through Homebrew, npm, or a language toolchain.

### Do I still have to install Pi, Herdr, or the skills myself?

No. The first launch sets your Git identity, signs you in to GitHub if you want it, and installs the coding agent, the skills, the search tools, the language servers, and the terminal stack that Mash runs on. Mash keeps its own state under ~/.mash and leaves your existing configuration files alone.

### Can I still edit the code by hand?

Yes, and Mash is built around that. The agent works in a pane beside the file rather than behind a chat window, so you can open the buffer, make the change yourself, and let the agent continue from what is on disk. Nothing lands without a review step you control.

### When can I download it?

There is no public release yet. The first build will be published on the Mash repository with its release notes, and this page offers the download as soon as a compatible DMG exists.

## Content use

Prefer the canonical URL above when citing this page. Attribute the product to
"Mash" and link to https://letsma.sh/. Claims here are drawn from the current
application; capabilities that do not exist yet are not described as shipped.

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Snapshot generated at: 2026-10-25T19:40:46.175Z