A crew of small AI worker bots you host yourself (alpha).

Website · Install · Features · Development · Architecture

Alpha. Cobble is still in alpha: interfaces, database schema and settings change between releases, and things break. Install it to try it out and to tell us what is wrong, but keep your own backups (Settings > Backups) and do not put it in front of work you cannot lose. Every release is a real release: the installer updates an existing install in place and keeps its data.

Cobble is a self-hosted crew of small AI worker bots. You get a coordinator and a set of workers, each with its own job, models, memory and workspace. They talk to you in one chat, share workspaces, run routines on a schedule, and drive their own computers: Docker sandboxes with a browser, a terminal, a code editor and a desktop that a bot can use and hand back to you when it needs help.

It is an install, not a SaaS. One SQLite database, one Docker container, and your data on your own machine.

Why small workers instead of one big assistant

• A crew, not a chat. Each worker has one job and only loads the context for it. A five-bot crew does five things in parallel, and each one stays cheap and focused.
• Bots you can see through. The face on each stone is the status: idle, working, done, asleep, needs you. You read the whole crew at a glance instead of asking each one what it is doing.
• Real computers. Workers run on your own sandboxed machines, with browser, terminal, files and desktop, not just a tool loop.
• Yours. Self-hosted, MIT, one SQLite file to back up, no account and no per-seat billing.

Features

Area	What you get
Crew	One coordinator and as many workers as you need, each with a name, a role, a hue and its own core instructions
Rail	The coordinator, your recent workers and their latest sessions, then your workspaces, each row carrying its status line
Chat	Markdown with @-mentions for bots and #-mentions for workspaces, replies and quotes, reactions, attachments, older messages on scroll, drafts kept locally
Stop	Stop a bot from the thinking row or the header menu: its queued and running work stops at once, everywhere you chat with it, and it goes idle
Header	The bot's model, provider and computer at a glance, one click from either, and its picture, instructions and settings on the avatar
Workspaces	A shared home for a group of bots: shared context, per-workspace instructions and memory, a default computer, and a dashboard
Memory	Each bot keeps core memory, memory about you, and workspace memory, and rewrites it as it works
Routines	Cron schedules per bot, written in chat, that queue a task on its own
Computers	Docker sandboxes with browser, terminal, code editor and desktop, opened from the chat and handed back to you mid-task
Files	Bots keep files on your data volume, search them by meaning, and attach the ones they make to a reply
Models	OpenRouter, OpenAI, Anthropic, Gemini, DeepSeek, Groq, Mistral, xAI, Ollama or any OpenAI-compatible server, per bot and per harness
Voice	Dictate into the composer, play any bot reply, with speech-to-text and text-to-speech models of your choice
Tools	Install your own MCP servers and custom HTTP, script or prompt tools, and give them to bots or workspaces
Skills	Write runbooks your bots follow. Each bot sees what a skill is for and reads the whole thing only when it needs it
App	Installable PWA with Web Push, dark mode, and a rail built for a phone

Screenshots

A workspace dashboard: what it is, its latest activity, the bots in it with their instructions there, and its computers.

Install

On a Linux machine with Docker (the installer adds Docker when it is missing):

curl -fsSL https://url.moduletrace.com/cobble | sudo bash

The app serves plain HTTP on the port it prints, usually http://<your-ip>:7227. Put a reverse proxy or tunnel in front of it for HTTPS (see HTTPS), then open the proxy's address and create the super admin account. The first signup also creates the coordinator and the main computer, which pulls the sandbox image in the background. Give it a few minutes.

Then open Settings > Models, add an OpenRouter key (or another provider) and wait for the model list to sync. This is what the bots think with.

Requirements

• Linux amd64 or arm64, with Docker. The installer installs Docker from get.docker.com when it is missing.
• 2 CPU cores, 4 GB RAM and 20 GB free disk for the app plus one computer. Each computer is its own container with its own memory limit.
• Docker Desktop on macOS works for development and small installs, but Linux is the supported host.
• Port 7227, or another port with --port.
• A reverse proxy or tunnel in front for HTTPS. The app itself serves plain HTTP and never handles certificates.

The installer binds to 0.0.0.0 so the app is reachable from your phone on the same network. Use --bind 127.0.0.1 when a reverse proxy is the only thing that should reach it.

The app container itself is limited to 1 CPU and 2 GB of memory, since the heavy work happens in the computers' own containers. Change that with --cpus and --memory; each computer keeps its own limits.

HTTPS

Cobble serves plain HTTP. Terminate TLS in front of it with a reverse proxy (Caddy, nginx, Traefik) or a tunnel (Cloudflare Tunnel, Tailscale Serve), and point that at http://<this machine>:7227:

• Let the proxy set X-Forwarded-Proto: https. Cobble reads it to mark the sign-in cookies Secure; Caddy does this by default, and nginx needs proxy_set_header X-Forwarded-Proto $scheme;.
• Pass /ws through as well as ordinary requests, including the upgrade.
• Give the proxy a real certificate. Browsers treat plain HTTP as unsafe, so the installable app, offline support, Web Push notifications and voice recording stay off until the address is HTTPS.

Nothing on the machine needs a certificate installed: the browser only ever talks to the proxy. See the Help page in the app for the common proxy fixes.

Update and uninstall

The same script is the updater. It keeps the database, media, computers' home directories and generated secrets, backs up the database before replacing the container, and does nothing when the image has not changed.

curl -fsSL https://url.moduletrace.com/cobble | sudo bash

# Stop the app and keep the data
curl -fsSL https://url.moduletrace.com/cobble | sudo bash -s -- --uninstall

# Stop the app and delete the data
curl -fsSL https://url.moduletrace.com/cobble | sudo bash -s -- --uninstall --purge

Options

Option	Meaning
--home DIR	Install directory, default /opt/cobble
--data-dir DIR	Data directory mounted at /data, default HOME/data
--port PORT	Host port, default 7227
--bind ADDRESS	Host address to publish on, default 0.0.0.0
--cpus N	CPU cores for the app container, default 1
--memory MB	Memory for the app container in MB, default 2048
--image IMAGE	Container image, default ghcr.io/moduletrace/cobble
--version TAG	Image tag, default latest
--extra-network NET	Join another Docker network, for a tunnel or reverse proxy
--force	Recreate the container even when it is current
--no-pull	Use an image that is already on the machine
--skip-backup	Update without a database backup
--no-docker-install	Fail instead of installing Docker
--yes, -y	Accept the defaults without asking
--uninstall	Stop and remove the app container
--purge	With --uninstall, also delete the data directory

How it fits together

You ── chat ── Coordinator ── delegates ── Workers
                   │                          │
                   ├── Workspaces ────────────┤
                   │   context, memory, bots  │
                   ├── Routines ──────────────┤
                   │   cron schedules         │
                   └── Computers ─────────────┘
                       docker sandboxes:
                       browser, terminal, code, desktop

• Coordinator is yours alone. It plans, delegates to workers, and keeps the crew in order. It is the only bot that reaches every worker.
• Workers are the crew. Each has a job, its own instructions and memory, and its own models if you want to tune cost per bot.
• Workspaces group bots around a subject. Models, instructions, memory and the default computer resolve per workspace before per bot.
• Routines are cron schedules that queue a task without you asking.
• Computers are per-install Docker containers. Bots use them through the sandbox's tools, and you can open the same machine in the browser and take over.

Each conversation is split into sessions, so a long-running bot does not grow one endless thread: the bot names a session, summarizes it, and carries the summary into the next one.

Data and settings

Everything that must survive an update lives under the install directory:

/opt/cobble/
  .env                  # generated once, mode 600
  install.conf          # installer state
  backups/              # pre-update database snapshots
  backups-archives/     # whole-data archives, from Settings > Backups
  data/
    db/cobble
    db/.backups/
    media/
    computers/<id>/     # each computer's home directory
    bots/<id>/          # each bot's files
    workspaces/<id>/    # files shared in a workspace

.env holds the port and the encryption keys. The keys encrypt sessions and settings, so keep a copy and do not rotate them without re-entering provider keys and other secrets. Provider keys, MCP servers, tools and app settings are managed in the app, not in .env.

Edit .env and run docker restart cobble to apply changes. The installer only appends missing values and keeps what is already there, apart from the port it manages.

Settings > Backups makes two kinds of copy. Database snapshots (bun-sqlite's backup command) stay in data/db/.backups and can be restored from the app. Whole-data archives are a tar.gz of the entire data/ directory, written to backups-archives/ (mounted at /backups-archives, the BACKUP_ARCHIVE_DIR setting); every entry sits under one folder named after the archive, so extracting one by hand drops a single folder. Each group can create a copy, restore from one (a listed row, or a file uploaded from the button beside Create), download it and delete it; the newest five archives are kept.

The app container is started with the Docker socket mounted and MAIN_SERVER=1, so it can create computer containers and run cron, the queue and Web Push.

Images

Every release publishes a multi-arch image to ghcr.io/moduletrace/cobble, which is what the installer pulls. Tags are latest, the release version, major.minor and the commit sha.

The same image is copied into git.tben.me/moduletrace/cobble by bun run mirror:gitea, which runs after the build over the VPN (the Gitea registry is not on the public internet, so GitHub Actions cannot reach it). Install from Gitea with --image git.tben.me/moduletrace/cobble, or build from source with docker build -t cobble:local . and --image cobble --version local --no-pull.

A release is published from a clean main with the two scripts, which tag the package.json version, push and create the release objects:

scripts/publish-github.sh   # or: bun run publish:github
scripts/publish-gitea.sh    # or: bun run publish:gitea

Both take --version VERSION, --dry-run and --yes. Only the GitHub release builds the image, and the Gitea registry is filled in afterwards, once that build has finished and from the VPN, by bun run mirror:gitea; see RELEASING.md for the full checklist.

Development

cp .env.example .env
# set ENCRYPTION_KEY and ENCRYPTION_SALT (openssl rand -hex 32)
bun install
bun run db:schema
bun run dev

Open http://localhost:7227. With no users, every page goes to /auth/signup to create the super admin. For a headless setup:

SEED_SUPER_ADMIN_PASSWORD=... bun run seed

The development server serves plain HTTP, the same as the container. To try the app from a phone, run a proxy or tunnel in front of it (see HTTPS); the installed app, Web Push and voice need that secure context.

Command	Purpose
bun run dev	Development server
bun run start	Production server on the host
bun run typecheck	Type-check
bun run test	Run the test suite
bun run check:bundle	Bundle budget after a build
bun run seed	Create the super admin from the CLI
bun run seed:bots	Add a sample crew
bun run db:schema	Sync the schema and types
bun run gen:favicon	Regenerate favicons and PWA assets

Plain Node does not work: the app runs on Bun. The stack is Bun, @moduletrace/bunext for filesystem routing, SQLite via @moduletrace/bun-sqlite, Tailwind CSS and the @moduletrace/twui component library. The model layer is one adapter over OpenAI-compatible APIs, so any compatible provider works.

See AGENTS.md for the full architecture, routes, queue, harness and data model. CI runs type-check and tests on every push and pull request; releases are built by GitHub Actions and pushed to both registries. See RELEASING.md for the release and launch checklist.

Contributing

Issues and pull requests are welcome, in English, on either GitHub or Gitea. Run bun run typecheck and bun run test before opening a pull request, and read AGENTS.md first: it documents the conventions the code follows.

License

MIT. See LICENSE.