Build separate python image for antigravity harness

cmd/ax/Dockerfile

@@ -12,14 +12,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Comprehensive AX image: the Go `ax` binary plus the Antigravity Python sidecar
-# (SDK, localharness, agent), on a Debian-based image with shell tooling for
-# skills/code execution. Used by both the ax-server (`ax serve`) and the harness
-# actor (`ax harness`, which forks the Python sidecar).
+# Multi-target AX image build:
+#   --target antigravity : python:3.13-slim + the Antigravity Python sidecar
+#                          (SDK, localharness, agent). Used by the antigravity
+#                          harness actor (`ax harness antigravity`).
+#   --target ax          : debian:stable-slim + the Go `ax` binary. Used by 
+#                          the ax-server (`ax serve`) and the Go interactions 
+#                          harness actor (`ax harness antigravity-interactions`).
 #
-# Build context: repository root. The image targets the cluster's linux/amd64
-# nodes, so it is built with `--platform linux/amd64`. For a standalone build:
-#   docker build --platform linux/amd64 -f cmd/ax/Dockerfile -t <ref> . && docker push <ref>
+# Build context: repository root. Images target the cluster's linux/amd64 nodes,
+# so build with `--platform linux/amd64`. 
+# For a standalone build:
+#   docker build --platform linux/amd64 --target antigravity -f cmd/ax/Dockerfile -t <ref> . && docker push <ref>
+#   docker build --platform linux/amd64 --target ax -f cmd/ax/Dockerfile -t <ref> . && docker push <ref>
 
 # --- Stage 1: build the ax Go binary (with the harness build tag) -------------
 FROM --platform=$BUILDPLATFORM golang:1.26 AS build
@@ -32,7 +37,8 @@ COPY . .
 RUN CGO_ENABLED=0 GOOS=${TARGETOS} GOARCH=${TARGETARCH} \
     go build -o /out/ax ./cmd/ax
 
-FROM python:3.13-slim
+# --- antigravity image -------
+FROM python:3.13-slim AS antigravity
 WORKDIR /workspace
 
 RUN apt-get update \
@@ -73,3 +79,23 @@ EXPOSE 80
 # which serves the HarnessService on :80.
 CMD ["/ax-app/ax", "harness", \
      "--host", "0.0.0.0", "--port", "80"]
+
+# --- ax image (Go-only) for the interactions harness and ax-server -----------
+FROM debian:stable-slim AS ax
+WORKDIR /workspace
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+        ca-certificates \
+        curl \
+        less \
+        procps \
+        wget \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY --from=build /out/ax /ax-app/ax
+
+EXPOSE 80
+
+CMD ["/ax-app/ax", "harness", "antigravity-interactions", \
+     "--host", "0.0.0.0", "--port", "80"]

hack/install-ax.sh

@@ -105,10 +105,13 @@ detect_container_engine() {
   fi
 }
 
-# build_ax_image builds and pushes the comprehensive ax image (the Go ax binary
-# plus the Antigravity Python sidecar) and echoes its digest-pinned reference on
-# stdout. Requires AX_IMAGE_REPO and a container engine.
-build_ax_image() {
+# _build_and_push_ax builds one target of cmd/ax/Dockerfile into ${repo}:<git-sha>,
+# pushes it, and echoes the digest-pinned reference on stdout. Args:
+#   $1 repo   - fully-qualified image repo (e.g. gcr.io/proj/ax)
+#   $2 target - Dockerfile target stage (ax | antigravity)
+# Requires AX_IMAGE_REPO and a container engine.
+_build_and_push_ax() {
+  local repo="$1" target="$2"
   if [[ -z "${AX_IMAGE_REPO:-}" ]]; then
     echo "Error: AX_IMAGE_REPO environment variable must be set" >&2
     exit 1
@@ -120,14 +123,14 @@ build_ax_image() {
     exit 1
   fi
 
-  local repo tag image digest
-  repo="${AX_IMAGE_REPO}/ax"
+  local tag image digest
   tag="$(git rev-parse --short HEAD)"
   image="${repo}:${tag}"
 
-  log_step "build_ax_image -> ${image}" >&2
+  log_step "build ${target} -> ${image}" >&2
   "${CONTAINER_ENGINE}" build \
     --platform linux/amd64 \
+    --target "${target}" \
     -f cmd/ax/Dockerfile \
     -t "${image}" \
     . 2>&1 \
@@ -156,6 +159,18 @@ build_ax_image() {
   echo "${repo}@${digest}"
 }
 
+# build_ax_image builds and pushes the Go-only ax image used by the ax-server and the
+# Go interactions harness.
+build_ax_image() {
+  _build_and_push_ax "${AX_IMAGE_REPO}/ax" ax
+}
+
+# build_ax_antigravity_image builds and pushes the antigravity image used by the
+# antigravity harness.
+build_ax_antigravity_image() {
+  _build_and_push_ax "${AX_IMAGE_REPO}/ax-antigravity" antigravity
+}
+
 build_ateom_image() {
   if [[ -n "${ATEOM_IMAGE:-}" ]]; then
     echo "${ATEOM_IMAGE}"
@@ -206,8 +221,9 @@ deploy_ax_server() {
   echo "Using GCS Bucket: ${AX_SNAPSHOTS_BUCKET}"
 
   # Build and push the images, capturing their digest-pinned references.
-  local ax_image ateom_image
+  local ax_image ax_antigravity_image ateom_image
   ax_image=$(build_ax_image)
+  ax_antigravity_image=$(build_ax_antigravity_image)
   ateom_image=$(build_ateom_image)
 
   # Resolve the event-log Postgres DSN. By default ax-server connects to an
@@ -241,6 +257,7 @@ deploy_ax_server() {
     -e "s|\${GEMINI_API_KEY}|${GEMINI_API_KEY}|g"
     -e "s|\${AX_SNAPSHOTS_BUCKET}|${AX_SNAPSHOTS_BUCKET}|g"
     -e "s|\${AX_IMAGE}|${ax_image}|g"
+    -e "s|\${AX_ANTIGRAVITY_IMAGE}|${ax_antigravity_image}|g"
     -e "s|\${ATEOM_IMAGE}|${ateom_image}|g"
     -e "s|\${GOOGLE_CLOUD_PROJECT}|${GOOGLE_CLOUD_PROJECT:-}|g"
     -e "s|\${AX_CONFIG_CONTENT}|${ax_config_content}|g"

manifests/README.md

@@ -18,22 +18,27 @@ The target Kubernetes cluster is assumed to have
 ### 1. Build and Deploy
 
 > [!NOTE]
-> Do not manually edit `manifests/ax-deployment.yaml`. The installation script automatically injects your `${GEMINI_API_KEY}`, `${AX_SNAPSHOTS_BUCKET}`, and the built `${AX_IMAGE}` and `${ATEOM_IMAGE}` references during deployment.
+> Do not manually edit `manifests/ax-deployment.yaml`. The installation script automatically injects your `${GEMINI_API_KEY}`, `${AX_SNAPSHOTS_BUCKET}`, and the built `${AX_IMAGE}`, `${AX_ANTIGRAVITY_IMAGE}`, and `${ATEOM_IMAGE}` references during deployment.
 
 The installation script builds the required images and applies the resolved
 manifests to your cluster:
 
-- the comprehensive **ax** image, built from `cmd/ax/Dockerfile`,
+- the **ax** image (the Go `ax` binary only), built from the `ax`
+  target of `cmd/ax/Dockerfile`; used by the ax-server and the Go interactions
+  harness,
+- the **ax-antigravity** image (the Antigravity Python
+  sidecar: SDK, localharness, agent), built from the `antigravity` target of
+  `cmd/ax/Dockerfile`; used by the antigravity harness actor,
 - the **ateom-gvisor** worker image, built with `ko` from the `go.mod` pinned
   substrate module.
 
 #### Build prerequisites
 
-The ax image bundles the antigravity SDK, installed from PyPI at build time.
-The image targets the cluster's **linux/amd64**
-nodes and is built with `--platform linux/amd64`.
+The ax-antigravity image bundles the antigravity SDK, installed from PyPI at
+build time. Both images target the cluster's **linux/amd64**
+nodes and are built with `--platform linux/amd64`.
 
-You also need a container engine to build and push the ax image. The script
+You also need a container engine to build and push the ax images. The script
 auto-detects one (preferring a **running** docker, then podman); force a choice
 with `CONTAINER_ENGINE=docker` or `CONTAINER_ENGINE=podman`:
 
@@ -45,9 +50,10 @@ with `CONTAINER_ENGINE=docker` or `CONTAINER_ENGINE=podman`:
 
 #### Registry authentication
 
-`GOOGLE_CLOUD_PROJECT` sets `AX_IMAGE_REPO=gcr.io/$GOOGLE_CLOUD_PROJECT`. The deploy pushes two
-images — the **ax** image (via your container engine) and the **ateom** image
-(via `ko`) — and both authenticate through the gcloud credential helper:
+`GOOGLE_CLOUD_PROJECT` sets `AX_IMAGE_REPO=gcr.io/$GOOGLE_CLOUD_PROJECT`. The deploy pushes three
+images — the **ax** and **ax-antigravity** images (via your container engine) and
+the **ateom** image (via `ko`) — and all authenticate through the gcloud
+credential helper:
 
 ```bash
 gcloud auth login              # authenticate gcloud

manifests/ax-deployment.yaml

@@ -50,7 +50,7 @@ spec:
   pauseImage: "gcr.io/gke-release/pause@sha256:bcbd57ba5653580ec647b16d8163cdd1112df3609129b01f912a8032e48265da"
   containers:
     - name: "axantigravity"
-      image: ${AX_IMAGE}
+      image: ${AX_ANTIGRAVITY_IMAGE}
       # Substrate ignores the image CMD/ENV/WORKDIR, so the harness command and
       # environment are specified here. `ax harness antigravity` forks the
       # Antigravity Python sidecar, which serves on port 80 because substrate