diff --git a/.env.hub.example b/.env.hub.example
index 6152d864..83625211 100644
--- a/.env.hub.example
+++ b/.env.hub.example
@@ -1,6 +1,11 @@
 # Builder hub environment. Copy this to .env.hub (never committed) and fill in every
 # line marked "Secret" with its own random value: openssl rand -hex 32
 
+# --- Docker Compose ----------------------------------------------------------
+# The published images deploy/compose.yml runs: rc (newest release candidate),
+# latest (newest stable), main (every merge), an exact version or a commit sha.
+BUILDER_VERSION=rc
+
 # --- Database (required) -----------------------------------------------------
 # Postgres 17. Docker Compose starts one with these values.
 DB_HOST=127.0.0.1
@@ -89,8 +94,9 @@ PRODUCT_HELLO_WORDING=
 # Agents run in sidecars. By default the hub starts them as local processes.
 # Most local sidecars running at once.
 # SIDECAR_LOCAL_MAX_ACTIVE=16
-# Optional Docker sidecars: build the image with `bun run docker:sidecar`, then set it.
-# deploy/compose.docker-sidecars.yml sets them for the hub container.
+# Optional Docker sidecars. deploy/compose.docker-sidecars.yml sets them for the hub
+# container, with the published sidecar image at BUILDER_VERSION. From source, build
+# it with `bun run docker:sidecar` and set:
 # SIDECAR_IMAGE=corbits-builder-sidecar:local
 # SIDECAR_DOCKER_HOST=unix:///var/run/docker.sock
 # The group owning the Docker socket for deploy/compose.docker-sidecars.yml: 0 on Docker Desktop.
diff --git a/README.md b/README.md
index 15e0170f..88c4503a 100644
--- a/README.md
+++ b/README.md
@@ -41,10 +41,11 @@ Set up Builder on this machine with the corbits-builder-install skill. Use Docke
 **With Docker.**
 
 ```sh
-git clone https://github.com/corbitsdev/corbits-builder.git
-cd corbits-builder
-cp .env.hub.example .env.hub   # fill in each line marked Secret
-docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml up -d --build
+mkdir builder && cd builder
+base=https://raw.githubusercontent.com/corbitsdev/corbits-builder/main
+curl -fsSLO "$base/deploy/compose.yml"
+curl -fsSL "$base/.env.hub.example" -o .env.hub   # fill in each line marked Secret
+docker compose --env-file .env.hub -f compose.yml up -d
 ```
 
 Open http://localhost:8000. Ports, logs and running on a server are in
diff --git a/deploy/compose.build.yml b/deploy/compose.build.yml
new file mode 100644
index 00000000..7bc5931f
--- /dev/null
+++ b/deploy/compose.build.yml
@@ -0,0 +1,12 @@
+# Builds the hub from this checkout instead of pulling the published image:
+#   docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml -f deploy/compose.build.yml up -d --build
+x-build: &build
+  image: corbits-builder-hub:local
+  build:
+    context: .
+    dockerfile: deploy/Dockerfile
+    target: hub
+
+services:
+  hub: *build
+  setup: *build
diff --git a/deploy/compose.docker-sidecars.yml b/deploy/compose.docker-sidecars.yml
index 66e8ef00..3cf42871 100644
--- a/deploy/compose.docker-sidecars.yml
+++ b/deploy/compose.docker-sidecars.yml
@@ -1,11 +1,21 @@
 # Lets the hub also start sidecars as containers on the host's Docker daemon:
 #   docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml -f deploy/compose.docker-sidecars.yml up -d
-# Build the image on that daemon first with `bun run docker:sidecar`.
+# `sidecar-image` pulls SIDECAR_IMAGE onto that daemon before the hub starts;
+# `docker compose pull` refreshes it after a channel change.
+# From source, `bun run docker:sidecar` builds corbits-builder-sidecar:local;
+# set SIDECAR_IMAGE to that.
 # Access to the socket is root on the host.
 services:
+  sidecar-image:
+    image: ${SIDECAR_IMAGE:-ghcr.io/corbitsdev/corbits-builder-sidecar:${BUILDER_VERSION:-rc}}
+    entrypoint: ["true"]
+    restart: "no"
   hub:
+    depends_on:
+      sidecar-image:
+        condition: service_completed_successfully
     environment:
-      SIDECAR_IMAGE: ${SIDECAR_IMAGE:-corbits-builder-sidecar:local}
+      SIDECAR_IMAGE: ${SIDECAR_IMAGE:-ghcr.io/corbitsdev/corbits-builder-sidecar:${BUILDER_VERSION:-rc}}
       SIDECAR_DOCKER_HOST: unix:///var/run/docker.sock
     # The group that owns the socket inside the container: 0 on Docker Desktop,
     # the host's docker group id (`getent group docker`) on Linux.
diff --git a/deploy/compose.yml b/deploy/compose.yml
index 4f60a477..711859c2 100644
--- a/deploy/compose.yml
+++ b/deploy/compose.yml
@@ -1,12 +1,11 @@
-# Run from the repo root with `--project-directory .` so compose keeps the
-# repo-named project and resolves paths from the root, and `--env-file .env.hub`
-# so the values below interpolate from it:
+# Runs the published images. Pass `--env-file .env.hub` so the values below,
+# BUILDER_VERSION among them, interpolate from it. From a checkout, run from the
+# repo root with `--project-directory .`; anywhere else, keep .env.hub beside
+# this file:
 #   docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml up -d
+# deploy/compose.build.yml builds the images from source instead.
 x-hub: &hub
-  build:
-    context: .
-    dockerfile: deploy/Dockerfile
-    target: hub
+  image: ghcr.io/corbitsdev/corbits-builder-hub:${BUILDER_VERSION:-rc}
   env_file: .env.hub
   environment:
     DB_HOST: db
@@ -42,8 +41,6 @@ services:
       timeout: 3s
       retries: 30
   hub:
-    # No image name: Compose tags it after the project, so two checkouts never
-    # share one image.
     <<: *hub
     ports:
       - "127.0.0.1:${PORT:-8000}:${PORT:-8000}"
diff --git a/docs/SELF_HOST.md b/docs/SELF_HOST.md
index de1c2f77..b27f2e88 100644
--- a/docs/SELF_HOST.md
+++ b/docs/SELF_HOST.md
@@ -5,16 +5,23 @@ in [DEV.md](https://github.com/corbitsdev/corbits-builder/blob/main/docs/DEV.md)
 You need Docker with Compose and an API key or subscription login for at least
 one [model provider](#models).
 
-`deploy/compose.yml` runs Postgres 17 and the hub, which applies the
-migrations, then serves the API and the UI. Run every compose command from the
-repo root.
+`deploy/compose.yml` runs Postgres 17 and the published hub image, which
+applies the migrations, then serves the API and the UI. It needs no clone.
 
-## Configure
+## Install
 
 ```sh
-cp .env.hub.example .env.hub
+mkdir builder && cd builder
+base=https://raw.githubusercontent.com/corbitsdev/corbits-builder/main
+curl -fsSLO "$base/deploy/compose.yml"
+curl -fsSL "$base/.env.hub.example" -o .env.hub
 ```
 
+Replace `main` with a release tag (`v<version>`) to pin these files to that
+release. Every command below runs from this folder.
+
+## Configure
+
 Give each secret `.env.hub` marks its own random value, for example from
 `openssl rand -hex 32`; Builder refuses to start without them. Losing or
 changing the encryption keys makes stored provider keys unreadable. Every other
@@ -26,6 +33,11 @@ people open, and `HUB_PUBLIC_URL`, `HUB_API_ORIGIN` and `UI_PUBLIC_URL` when
 they differ from it. If a port is taken, `PORT` moves Builder (default `8000`)
 and `DB_PORT` the database (default `5433`).
 
+`BUILDER_VERSION` picks the published images
+(`ghcr.io/corbitsdev/corbits-builder-hub` and `-sidecar`): `rc` (default, the
+newest release candidate), `latest` (the newest stable release), `main` (every
+merge), an exact version such as `0.1.0-rc.1`, or a full commit sha.
+
 ## Models
 
 Connect a provider in the UI under **Settings → Providers**, or set its key in
@@ -47,9 +59,9 @@ How profiles map models to roles is in
 ## Run it
 
 ```sh
-docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml up -d --build   # start or update
-docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml logs -f hub     # follow the logs
-docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml down            # stop, keep the data
+docker compose --env-file .env.hub -f compose.yml up -d          # start
+docker compose --env-file .env.hub -f compose.yml logs -f hub    # follow the logs
+docker compose --env-file .env.hub -f compose.yml down           # stop, keep the data
 ```
 
 Open http://localhost:8000 (or your `PORT`), create an account, then add a
@@ -57,8 +69,13 @@ provider under **Settings → Providers**, or set a provider key in `.env.hub` b
 starting. With one provider, projects run on its profile; with several, each
 person picks one under **Settings → Profiles**
 ([how the choice works](https://github.com/corbitsdev/corbits-builder/blob/main/docs/DEV.md#model-profile-choice)).
-To update, pull the new commits and start it again; the hub applies new
-migrations as it starts.
+To update, or to switch channel after changing `BUILDER_VERSION`, pull the
+images and start it again; the hub applies new migrations as it starts:
+
+```sh
+docker compose --env-file .env.hub -f compose.yml pull
+docker compose --env-file .env.hub -f compose.yml up -d
+```
 
 Login with ChatGPT and Login with xAI finish by sending the browser to
 `localhost:1455` and `localhost:1456`, so they work only when the browser runs
@@ -73,9 +90,20 @@ To create a machine account and workspace without the UI, set the
 `BOOTSTRAP_*` values in `.env.hub` and run the `setup` service once:
 
 ```sh
-docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml --profile setup run --rm setup
+docker compose --env-file .env.hub -f compose.yml --profile setup run --rm setup
 ```
 
+## From source
+
+In a clone, `deploy/compose.build.yml` builds the hub image from the checkout
+instead of pulling it. Run from the repo root with `.env.hub` there:
+
+```sh
+docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml -f deploy/compose.build.yml up -d --build
+```
+
+`bun run docker:up` runs the same.
+
 ## Sidecars in Docker
 
 Agents run in sidecars. By default the hub starts them as processes beside
@@ -83,12 +111,13 @@ itself, inside the hub container. With `SIDECAR_IMAGE` set, it can also
 start them as containers on the Docker daemon at `SIDECAR_DOCKER_HOST`.
 
 ```sh
-docker build -f deploy/Dockerfile --target sidecar -t corbits-builder-sidecar:local .
-docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml -f deploy/compose.docker-sidecars.yml up -d --build
+curl -fsSLO https://raw.githubusercontent.com/corbitsdev/corbits-builder/main/deploy/compose.docker-sidecars.yml
+docker compose --env-file .env.hub -f compose.yml -f compose.docker-sidecars.yml up -d
 ```
 
-- Build the image on the daemon the hub uses; the hub checks that it exists
-  when it starts.
+- Compose pulls the sidecar image for your `BUILDER_VERSION` before the hub
+  starts, and `docker compose pull` refreshes it with the hub. From source, `bun run docker:sidecar` builds
+  `corbits-builder-sidecar:local`; set `SIDECAR_IMAGE` to it in `.env.hub`.
 - `deploy/compose.docker-sidecars.yml` mounts `/var/run/docker.sock` into the hub and
   adds the socket's group (`DOCKER_SOCKET_GID`: `0` on Docker Desktop, the
   host's `docker` group id on Linux). Access to that socket is root on the
diff --git a/package.json b/package.json
index 74d7c5b9..c3a86834 100644
--- a/package.json
+++ b/package.json
@@ -24,7 +24,7 @@
     "start": "exec bun --env-file=.env.hub --conditions=intx-src apps/hub/src/server.ts",
     "db:migrate": "bun --env-file=.env.hub --conditions=intx-src apps/hub/src/migrate.ts",
     "db:generate": "bun --conditions=intx-src ./node_modules/drizzle-kit/bin.cjs generate --config=apps/hub/drizzle.config.ts",
-    "docker:up": "docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml up -d --build",
+    "docker:up": "docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml -f deploy/compose.build.yml up -d --build",
     "docker:sidecar": "docker build -f deploy/Dockerfile --target sidecar -t corbits-builder-sidecar:local .",
     "auth:bootstrap": "bun --env-file=.env.hub --conditions=intx-src apps/hub/src/setup.ts",
     "auth:emulate": "bun --env-file=.env.hub scripts/google-emulate.ts",
diff --git a/skills/corbits-builder-install/SKILL.md b/skills/corbits-builder-install/SKILL.md
index e94d5466..9c79dcae 100644
--- a/skills/corbits-builder-install/SKILL.md
+++ b/skills/corbits-builder-install/SKILL.md
@@ -1,6 +1,6 @@
 ---
 name: corbits-builder-install
-description: Gets Builder running on this machine, from finding or cloning the checkout to the person signing up and connecting a model provider. Use whenever someone wants to install, set up, run, start, self-host or try Builder (Corbits Builder, corbitsdev/corbits-builder), with Docker Compose or with their own Postgres, or when a Builder checkout won't start. For driving projects through Builder's API once it runs, use operate-corbits-builder instead.
+description: Gets Builder running on this machine, from downloading the Compose files or cloning the checkout to the person signing up and connecting a model provider. Use whenever someone wants to install, set up, run, start, self-host or try Builder (Corbits Builder, corbitsdev/corbits-builder), with Docker Compose or with their own Postgres, or when a Builder checkout won't start. For driving projects through Builder's API once it runs, use operate-corbits-builder instead.
 ---
 
 # Install Builder
@@ -17,13 +17,7 @@ instead.
 - **Keep an existing `.env.hub`.** Its keys already encrypt stored data; new ones
   lock Builder out of it.
 
-## 1. Find the checkout
-
-Work from the root of a Builder checkout (a folder with `deploy/compose.yml`).
-If the current folder is not one, ask where it is, or clone
-`https://github.com/corbitsdev/corbits-builder.git` where the person chooses.
-
-## 2. Choose a path
+## 1. Choose a path
 
 Suggest Docker Compose if `docker info` succeeds, otherwise their own Postgres 17. Let the person decide.
 
@@ -32,6 +26,25 @@ Suggest Docker Compose if `docker info` succeeds, otherwise their own Postgres 1
 | Docker Compose | Docker with Compose    | `http://localhost:8000` |
 | Own Postgres   | Bun 1.4.4, Postgres 17 | `http://localhost:5173` |
 
+## 2. Get the files
+
+**Docker Compose** runs published images and needs no clone. In a folder the
+person chooses (or the one holding their existing `compose.yml`), download
+what is missing:
+
+```sh
+base=https://raw.githubusercontent.com/corbitsdev/corbits-builder/main
+curl -fsSLO "$base/deploy/compose.yml"
+curl -fsSL "$base/.env.hub.example" -o .env.hub.example
+```
+
+In a Builder checkout, download nothing: use `--project-directory . -f deploy/compose.yml`
+wherever the steps below say `-f compose.yml`.
+
+**Own Postgres** runs from a Builder checkout (a folder with `deploy/compose.yml`
+and `package.json`). If the current folder is not one, ask where it is, or clone
+`https://github.com/corbitsdev/corbits-builder.git` where the person chooses.
+
 ## 3. Write `.env.hub` and `.env.web`
 
 If `.env.hub` exists, keep it. Otherwise `cp .env.hub.example .env.hub` and fill each
@@ -50,9 +63,9 @@ and `DB_PORT` (5433) the Compose database's. If a port is taken, set `PORT` or
 ## 4. Start Builder
 
 **Docker Compose**:
-`docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml up -d --build`
-builds and starts Builder and Postgres. It is up when the hub logs `Hub ready`
-(`docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml logs hub`).
+`docker compose --env-file .env.hub -f compose.yml up -d`
+pulls and starts Builder and Postgres. It is up when the hub logs `Hub ready`
+(`docker compose --env-file .env.hub -f compose.yml logs hub`).
 
 **Own Postgres**
 ([CONTRIBUTING.md](https://github.com/corbitsdev/corbits-builder/blob/main/CONTRIBUTING.md),
@@ -78,8 +91,8 @@ Wait for them to confirm before you call it done.
 **Docker Compose**:
 
 ```sh
-docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml stop   # stop, keep everything
-docker compose --env-file .env.hub --project-directory . -f deploy/compose.yml down   # remove containers, keep data
+docker compose --env-file .env.hub -f compose.yml stop   # stop, keep everything
+docker compose --env-file .env.hub -f compose.yml down   # remove containers, keep data
 ```
 
 `down -v` also deletes every account, project and stored key; run it only when