Sigil on Windows

Sigil runs on jac, and jac ships no Windows build yet. So on Windows, Sigil runs on Linux underneath, through Docker Desktop or WSL2. One installer sets up either one and gives you a sigil command in PowerShell and cmd that forwards to it:

irm https://github.com/sigilagent/sigil/releases/latest/download/install.ps1 | iex

It needs no Administrator rights. Running it again updates the install, and so does sigil update.

Which pathway you get

	Docker	WSL2
Picked when	Docker Desktop is running	Docker is not running and a WSL distro exists
Force it with	`$env:SIGIL_MODE = "docker"`	`$env:SIGIL_MODE = "wsl"`
What runs	the `sigil` container from `ghcr.io/sigilagent/sigil`	the regular Linux install (`install.sh`) inside your distro
Your files	your user folder, mounted at `/host`	every drive, under `/mnt/c`, `/mnt/d`, ...
Model-written code	stays inside the container	runs as you in the distro, as on Linux
Start at login	the container restarts with Docker Desktop (turn on "Start Docker Desktop when you sign in")	a scheduled task named `Sigil`, offered by the installer

If neither is ready, the installer tells you how to get one:

WSL2. In an Administrator PowerShell, run wsl --install -d Ubuntu, restart, and finish Ubuntu's first-run setup.
Docker. Install Docker Desktop and start it.

Using it

sigil                          # chat with your agent
sigil setup                    # connect a model
sigil compile .\SKILL.md       # paths are translated for you
sigil solve "turn C:\Users\me\report.pdf into a clean CSV"

The Observatory is at http://localhost:8199. After Sigil starts it takes a minute or two to come up, because it rebuilds its web client.

Paths. The sigil command maps two things onto Sigil's side: the folder you run it from, and any argument that names a file or folder that exists. That covers relative paths such as .\SKILL.md as well as absolute ones such as C:\data\a.csv. A path written inside a sentence, like the solve example above, is passed through unchanged. - In the Docker pathway the container only sees your user folder (/host). Run sigil from somewhere inside it, or set $env:SIGIL_WORKSPACE to another folder before installing. - In WSL, C:\x becomes /mnt/c/x.

Models. Every connection in connections works, with two exceptions: - Ollama. If it runs on Windows, the Docker pathway already points the container at http://host.docker.internal:11434. In WSL, Ollama inside the distro just works, and one on Windows needs OLLAMA_HOST set to its address. - Claude Code. The Claude Code connection drives the claude CLI, which would have to be installed where Sigil runs: inside the distro for WSL. It is not available in the container.

Browser sign-ins (ChatGPT, OpenRouter) open a link that you click on Windows. The container receives the sign-in on port 1455, which it publishes only on localhost.

Claude Code using Sigil's skills (claude-code) works the same as on macOS:

claude mcp add sigil -- sigil mcp-serve

Memory

Sigil's scheduler, Observatory and each command are separate jac processes. Together they can reach about 10 GB at peak. Docker Desktop and WSL2 give their Linux VM half your RAM plus swap worth a quarter of it, so a 16 GB PC is comfortable. On a smaller one, raise the VM's share in %USERPROFILE%\.wslconfig, then run wsl --shutdown:

[wsl2]
memory=12GB
swap=8GB

Updating and removing

sigil update re-runs the installer. In the Docker pathway it replaces the container and keeps your graph, compiled skills and settings, which live in the sigil-graph, sigil-skills and sigil-state volumes.

To remove the Docker pathway:

docker rm -f sigil
docker volume rm sigil-state sigil-graph sigil-skills   # deletes your agent's graph, skills and settings
Remove-Item -Recurse "$env:LOCALAPPDATA\Sigil"

To remove the WSL pathway:

Unregister-ScheduledTask Sigil -Confirm:$false
wsl -- rm -rf ~/.sigil ~/.local/bin/sigil
Remove-Item -Recurse "$env:LOCALAPPDATA\Sigil"

Both leave the sigil folder on your user PATH (%LOCALAPPDATA%\Sigil\bin). It is harmless once empty.

The image on its own

The Docker pathway is a plain image, so you can run it yourself:

docker run -d --name sigil --init --restart unless-stopped \
  -p 127.0.0.1:8199:8199 -p 127.0.0.1:1455:1455 \
  -v sigil-state:/home/jac/.sigil -v sigil-graph:/opt/jac/state/pg \
  -v sigil-skills:/opt/sigil/app/src/crystallized \
  -v "$HOME:/host" ghcr.io/sigilagent/sigil:latest
docker exec -it -w /host sigil sigil      # chat

Run every command in that one container with docker exec. Never start a second container on the same volumes: two embedded Postgres servers on one data directory corrupt it. To build the image from a checkout, run ./docker/build.sh.