diff --git a/Dockerfile b/Dockerfile
index 4e4628db5..d03af8146 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -75,6 +75,7 @@ RUN --mount=type=cache,target=/usr/local/cargo/registry \
 FROM python:${PYTHON_VERSION}-slim AS runtime-slim-base
 
 ARG RUNTIME_USER=nonroot
+ARG RUNTIME_HOME=/home/nonroot
 ARG PYTHON_SITE_PACKAGES
 
 RUN apt-get update && \
@@ -97,12 +98,19 @@ RUN mkdir -p /home/nonroot /data && \
     fi
 
 USER ${RUNTIME_USER}
-WORKDIR /home/nonroot
+WORKDIR ${RUNTIME_HOME}
 
 ENV HEADROOM_HOST=0.0.0.0 \
     PYTHONUNBUFFERED=1 \
     PYTHONDONTWRITEBYTECODE=1
 
+# Declare ~/.headroom as a volume so Docker (and ACA) can attach persistent
+# storage here.  Bare `docker run` gets an anonymous volume as a fallback so
+# state is never silently written to the ephemeral container layer.
+# RUNTIME_HOME defaults to /home/nonroot (the published image default); pass
+# --build-arg RUNTIME_HOME=/root when building with RUNTIME_USER=root.
+VOLUME ${RUNTIME_HOME}/.headroom
+
 EXPOSE 8787
 
 HEALTHCHECK --interval=30s --timeout=5s --start-period=20s --retries=3 \
@@ -137,4 +145,4 @@ ENTRYPOINT ["python3", "-m", "headroom.cli", "proxy"]
 CMD ["--host", "0.0.0.0", "--port", "8787"]
 
 # Default published image remains python-slim runtime
-FROM runtime-slim-base AS runtime
+FROM runtime-slim-base AS runtime
\ No newline at end of file
diff --git a/docker-compose.yml b/docker-compose.yml
index a3a30316e..dbb8b0f9e 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -9,6 +9,8 @@ services:
       # - OPENAI_TARGET_API_URL=https://api.x.ai
     ports:
       - "8787:8787"
+    volumes:
+      - headroom_workspace:/home/nonroot/.headroom
     healthcheck:
       test: ["CMD", "curl", "--fail", "--silent", "http://127.0.0.1:8787/readyz"]
       interval: 30s
@@ -46,5 +48,6 @@ services:
       - NEO4J_apoc_import_file_use__neo4j__config=true
 
 volumes:
+  headroom_workspace:    # persists proxy_savings, memory.db, session_stats, toin across image updates
   qdrant_data:
-  neo4j_data:
+  neo4j_data:
\ No newline at end of file