diff --git a/.env.shared.example b/.env.shared.example
new file mode 100644
index 0000000..ac090db
--- /dev/null
+++ b/.env.shared.example
@@ -0,0 +1,27 @@
+# ── Shared machine setup ─────────────────────────────────────────────
+# Your corporate signum / username (REQUIRED)
+# This isolates your container, config, and data from other users.
+SIGNUM=your-signum-here
+
+# ── Provider ─────────────────────────────────────────────────────────
+OPENCODE_PROVIDER=amazon-bedrock
+OPENCODE_MODEL=amazon-bedrock/eu.anthropic.claude-opus-4-6-v1
+AWS_REGION=eu-west-1
+AWS_PROFILE=default
+
+# ── Git ──────────────────────────────────────────────────────────────
+GIT_USER_NAME=Your Name
+GIT_USER_EMAIL=your.name@example.com
+
+# ── Paths (adjust to your layout) ───────────────────────────────────
+# Default: ~/src mounted as /workspace
+# WORKSPACE_PATH=~/src
+
+# SSH keys — defaults to shared ~/.ssh
+# If you have per-user keys: SSH_KEY_PATH=~/<signum>/.ssh
+# SSH_KEY_PATH=~/.ssh
+
+# ── Locale (defaults to en_US.UTF-8) ────────────────────────────────
+# LANG=sv_SE.UTF-8
+# LANGUAGE=sv_SE:sv
+# LC_ALL=sv_SE.UTF-8
diff --git a/README.md b/README.md
index 6266583..b6b5a06 100644
--- a/README.md
+++ b/README.md
@@ -271,6 +271,39 @@ volumes:
   - devbox-vscode:/home/developer/.vscode-server
 ```
 
+### Shared machine setup (multiple users, single OS account)
+
+For machines where multiple users share one OS account (e.g. a common `garage` user), a separate compose file isolates each user's config and data using a `SIGNUM` variable.
+
+Each user creates their own directory and setup:
+
+```bash
+# Replace <signum> with your username/identifier
+mkdir -p ~/<signum>/opencode-devbox
+cd ~/<signum>/opencode-devbox
+
+# Copy the shared-machine compose and env files
+cp /path/to/opencode-devbox/docker-compose.shared.yml docker-compose.yml
+cp /path/to/opencode-devbox/.env.shared.example .env
+
+# Create per-user config directory
+mkdir -p ~/<signum>/.config/opencode
+
+# Edit .env with your signum, provider, keys, etc.
+vim .env
+
+# Start
+docker compose up -d
+docker compose exec -u developer devbox-<signum> opencode
+```
+
+Each user's container, config, and named volumes are fully isolated:
+- Container name: `devbox-<signum>` (no collisions)
+- Named volumes: prefixed with the project directory name (automatic per-user isolation)
+- Opencode config: `~/<signum>/.config/opencode/` (per-user settings, OMOS config, etc.)
+
+See `docker-compose.shared.yml` and `.env.shared.example` for the full configuration.
+
 ### Rebuilding the Image
 
 `docker compose run` and `docker compose up` use the existing image — they **do not rebuild** when you change the Dockerfile or build args (e.g. updating `OPENCODE_VERSION`). Rebuild explicitly:
diff --git a/docker-compose.shared.yml b/docker-compose.shared.yml
new file mode 100644
index 0000000..28d81d5
--- /dev/null
+++ b/docker-compose.shared.yml
@@ -0,0 +1,50 @@
+# opencode-devbox docker-compose for shared machines
+#
+# For machines where multiple users share one OS account (e.g. 'garage').
+# Each user gets isolated config, data, and named volumes by setting
+# SIGNUM in their .env file.
+#
+# Setup per user:
+#   1. mkdir -p ~/<signum>/opencode-devbox && cd ~/<signum>/opencode-devbox
+#   2. cp docker-compose.shared.yml docker-compose.yml
+#   3. cp .env.shared.example .env
+#   4. Edit .env with your signum, provider, keys, etc.
+#   5. mkdir -p ~/<signum>/.config/opencode
+#   6. docker compose up -d
+#
+# Named volumes are automatically isolated per user because Docker Compose
+# prefixes them with the project directory name (e.g. opencode-devbox_devbox-data).
+# Since each user runs from ~/<signum>/opencode-devbox/, volumes don't collide.
+
+services:
+  devbox:
+    image: joakimp/opencode-devbox:latest
+    container_name: devbox-${SIGNUM:?Set SIGNUM in .env}
+    stdin_open: true
+    tty: true
+    env_file:
+      - .env
+    environment:
+      - TERM=xterm-256color
+    volumes:
+      # Host workspace — user's project directory
+      - ${WORKSPACE_PATH:-~/src}:/workspace
+
+      # SSH keys — user-specific if available, else shared
+      - ${SSH_KEY_PATH:-~/.ssh}:/home/developer/.ssh:ro
+
+      # Opencode config — per-user (persists settings across restarts)
+      - ${HOME}/${SIGNUM}/.config/opencode:/home/developer/.config/opencode
+
+      # Persist opencode data (auth, memory, session history)
+      - devbox-data:/home/developer/.local/share/opencode
+
+      # Persist uv data (Python installs)
+      - devbox-uv:/home/developer/.local/share/uv
+
+      # Optional: AWS credentials (per-user if available)
+      # - ${HOME}/${SIGNUM}/.aws:/home/developer/.aws
+
+volumes:
+  devbox-data:
+  devbox-uv: