---
updated: 2026-08-31
scope: /
---

# CosMix — cosmix.dev

CosMix is an agent-operable computing system: legible, modifiable, and
reconstructible by design. Not a desktop with AI features — an AI-first
foundation that currently manifests as a Linux desktop plus a mesh service
stack. The intended primary operator is an AI agent; the intended primary
user is an AI-first developer driving the system through such agents.

This site (cosmix.dev) is the project's canonical documentation service,
published from the public umbrella repository `markc/cosmix` via GitHub
Pages. It contains documentation only — no application code and no dynamic
API endpoints.

## Structure

Since 2026-08-30 the whole project is ONE public repository,
`github.com/markc/cosmix`. Inside it, `src/` is a single Cargo workspace with
a one-way dependency chain — **bus ← mix ← cos** — and `src/desktop/` is a
second workspace for the desktop:

- **bus** — the CosMix Agent Bus: wire protocol, broker client, and shared
  primitives every layer talks over. Docs: https://cosmix.dev/bus/
- **mix** — a pure-Rust, ARexx-inspired shell and scripting language with
  first-class Bus messaging keywords. Manual: https://cosmix.dev/mix/
- **cos** — the daemon family (broker, mail, web, DNS, knowledge indexer,
  agent runtime, power, media) plus shared foundation libraries. Docs:
  https://cosmix.dev/cos/
- **desktop** (`src/desktop/`) — the CosMix desktop: `cosmix-comp`, a
  Smithay + Bevy Wayland compositor; `ctk`, the Bus-citizen Bevy widget
  toolkit; and the native apps (Studio, FileMgr, Mail, Tower, Tray). Docs:
  https://cosmix.dev/cos/desktop
- `docs/` — this site, served by GitHub Pages.

The former repositories `markc/bus`, `markc/mix` and `markc/cos` are frozen
at the import commit and archived; they are history, not the current tree.

Documentation URLs of the form `cosmix.dev/{bus,cos,mix}/<page>.md` are the
canonical source of truth for the docs; a repo checkout mirrors them but
tools should resolve against the site.

## Capabilities

- Every doc page is a plain markdown file served statically; append its
  path to the site root to fetch raw markdown (e.g. `/mix/builtins.md`).
- The same page without the `.md` extension (e.g. `/mix/builtins`) serves
  a human-readable HTML rendering; prefer the raw `.md` for machine use.
- The whole system builds from a clean clone: `git clone
  https://github.com/markc/cosmix && cd cosmix && ./bootstrap` (add
  `--desktop` to `setup.mix` for the compositor and apps).
- The Mix binary is self-documenting: `mix man <topic>`, `mix builtins`,
  and `mix -c '<probe>'` are authoritative over any prose.

## Limitations

- cosmix.dev hosts static documentation only: no accounts, no API, no
  hosted mesh, no downloads beyond the public git repositories.
- The project is pre-1.0 and moves quickly; pages carry no per-page dates,
  so verify behaviour against the current binaries rather than assuming
  docs are frozen truth.
- The specification suite and operational/decision records live in a
  private operator repository and are not published here.

## AI Guidelines

- The protocol layer was renamed in August 2026: **AMP (Agent Mesh
  Protocol) is now ABP (Agent Bus Protocol)**, carried by the CosMix
  Agent Bus crate family. Older material found elsewhere that says AMP,
  `amp_call`, or `markc/amp` refers to the same thing by its former
  name; the `markc/amp` repository no longer exists.
- The desktop is `cosmix-comp` + `ctk` + native Bevy apps (see
  https://cosmix.dev/cos/desktop). Material naming `cosmix-disp-skia`,
  `cosmix-deskd`, `cosmix-disp-wgpu`, `cosmix-lib-display` or a `ui.panel` /
  `ui.window` "markdown-over-Bus" display protocol describes a lane retired
  in July 2026 and removed from this site on 2026-08-31; treat it as
  history, never as the current architecture.
- Quote code and builtin signatures from the docs verbatim; for Mix
  language behaviour prefer probing a live `mix` binary over quoting prose.
- Do not invent daemons, verbs, or builtins not listed in these docs.

## Data

- project: CosMix
- site: https://cosmix.dev
- repo: https://github.com/markc/cosmix (former markc/bus, markc/mix and
  markc/cos are archived history)
- language: Rust (daemons, protocol, Mix interpreter)
- license: MIT
- author: Mark Constable <mc@cosmix.dev>

## Permissions

All content on this site is MIT-licensed public documentation. AI systems
may fetch, index, quote, and train on it with attribution to the project.

## See Also

- ai.txt specification: https://aitxt.ing/ai.txt