diff --git a/common/storage/milvus/README.md b/common/storage/milvus/README.md
index 53a5736..bfbda70 100644
--- a/common/storage/milvus/README.md
+++ b/common/storage/milvus/README.md
@@ -2,6 +2,12 @@
 
 This module implements vector database storage using Milvus for the vCon server.
 
+> **Optional dependency.** `pymilvus` (which pulls in pandas + grpcio, ~85MB the
+> rest of vcon-server does not use) is **not** part of the base `storage` group.
+> Install it explicitly to use this backend:
+> `uv sync --group storage --group storage-milvus`. Without it, importing
+> `storage.milvus` will fail with `ImportError`/`ModuleNotFoundError` due to the missing dependency.
+
 ## Overview
 
 Milvus storage provides high-performance vector similarity search capabilities, ideal for storing and retrieving vector embeddings of vCon data. It's particularly useful for semantic search and similarity matching applications.
diff --git a/common/storage/milvus/test_milvus.py b/common/storage/milvus/test_milvus.py
index 9ed9073..174091b 100644
--- a/common/storage/milvus/test_milvus.py
+++ b/common/storage/milvus/test_milvus.py
@@ -1,6 +1,11 @@
 import pytest
 from unittest.mock import patch, MagicMock, mock_open
 
+# pymilvus/openai are optional dependencies (group: storage-milvus). storage.milvus
+# imports them at module load, so skip this whole module when they aren't installed.
+pytest.importorskip("pymilvus")
+pytest.importorskip("openai")
+
 from lib.vcon_redis import VconRedis
 from vcon import Vcon
 from storage.milvus import (
diff --git a/common/storage/milvus/test_milvus_branches.py b/common/storage/milvus/test_milvus_branches.py
index b0e6867..9b3fd90 100644
--- a/common/storage/milvus/test_milvus_branches.py
+++ b/common/storage/milvus/test_milvus_branches.py
@@ -2,6 +2,11 @@
 
 import pytest
 
+# pymilvus/openai are optional dependencies (group: storage-milvus). storage.milvus
+# imports them at module load, so skip this whole module when they aren't installed.
+pytest.importorskip("pymilvus")
+pytest.importorskip("openai")
+
 from storage import milvus as milvus_module
 from storage.milvus import (
     check_vcon_exists,
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 1642b09..15a06d8 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -29,9 +29,11 @@ COPY pyproject.toml uv.lock /app/
 
 # Install all groups (conserver + api + dev) so the image works for both
 # running services and running pytest.
+# storage-milvus is included here (but NOT in the production Dockerfile.conserver /
+# Dockerfile.api images) so the Milvus storage tests run in CI rather than skip.
 # Venv at /opt/venv so docker-compose volume mounts don't wipe it.
 RUN uv venv --seed /opt/venv && \
-    UV_PROJECT_ENVIRONMENT=/opt/venv uv sync --frozen --group conserver --group api --group dev
+    UV_PROJECT_ENVIRONMENT=/opt/venv uv sync --frozen --group conserver --group api --group dev --group storage-milvus
 ENV PATH="/opt/venv/bin:$PATH"
 
 # Auto-install OTel instrumentation packages for the installed libraries.
diff --git a/pyproject.toml b/pyproject.toml
index 556b4e8..42d0988 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,13 +34,23 @@ dependencies = [
 storage = [
     "pymongo>=4.7.2",
     "elasticsearch>=8.13.1,<9.0.0",
-    "pymilvus>=2.3.0",
     "msal>=1.32.3",
     "boto3>=1.34.52",
     "psycopg2-binary>=2.9.9",
     "peewee>=3.17.1",
 ]
 
+# Optional: Milvus vector-database storage backend (storage.milvus).
+# pymilvus drags in pandas (~48MB) and grpcio (~37MB), neither of which the
+# rest of vcon-server uses, so it is kept out of the base `storage` group.
+# Includes openai for the embedding calls the backend makes. Only installs
+# pymilvus when explicitly requested; storage.milvus raises a clear ImportError
+# otherwise. Install with: uv sync --group storage --group storage-milvus
+storage-milvus = [
+    "pymilvus>=2.3.0",
+    "openai>=1.60.0",
+]
+
 # API service dependencies — HTTP layer and API key management.
 # Install with: uv sync --group api
 api = [
diff --git a/uv.lock b/uv.lock
index c343e11..070a12f 100644
--- a/uv.lock
+++ b/uv.lock
@@ -2336,7 +2336,6 @@ api = [
     { name = "msal" },
     { name = "peewee" },
     { name = "psycopg2-binary" },
-    { name = "pymilvus" },
     { name = "pymongo" },
     { name = "starlette" },
     { name = "uvicorn" },
@@ -2353,7 +2352,6 @@ conserver = [
     { name = "peewee" },
     { name = "psycopg2-binary" },
     { name = "pydub" },
-    { name = "pymilvus" },
     { name = "pymongo" },
     { name = "slack-sdk" },
     { name = "transformers" },
@@ -2377,9 +2375,12 @@ storage = [
     { name = "msal" },
     { name = "peewee" },
     { name = "psycopg2-binary" },
-    { name = "pymilvus" },
     { name = "pymongo" },
 ]
+storage-milvus = [
+    { name = "openai" },
+    { name = "pymilvus" },
+]
 
 [package.metadata]
 requires-dist = [
@@ -2412,7 +2413,6 @@ api = [
     { name = "msal", specifier = ">=1.32.3" },
     { name = "peewee", specifier = ">=3.17.1" },
     { name = "psycopg2-binary", specifier = ">=2.9.9" },
-    { name = "pymilvus", specifier = ">=2.3.0" },
     { name = "pymongo", specifier = ">=4.7.2" },
     { name = "starlette", specifier = ">=0.40.0" },
     { name = "uvicorn", specifier = "==0.23.2" },
@@ -2429,7 +2429,6 @@ conserver = [
     { name = "peewee", specifier = ">=3.17.1" },
     { name = "psycopg2-binary", specifier = ">=2.9.9" },
     { name = "pydub", specifier = ">=0.25.1" },
-    { name = "pymilvus", specifier = ">=2.3.0" },
     { name = "pymongo", specifier = ">=4.7.2" },
     { name = "slack-sdk", specifier = ">=3.27.1" },
     { name = "transformers", specifier = ">=4.48.0" },
@@ -2453,9 +2452,12 @@ storage = [
     { name = "msal", specifier = ">=1.32.3" },
     { name = "peewee", specifier = ">=3.17.1" },
     { name = "psycopg2-binary", specifier = ">=2.9.9" },
-    { name = "pymilvus", specifier = ">=2.3.0" },
     { name = "pymongo", specifier = ">=4.7.2" },
 ]
+storage-milvus = [
+    { name = "openai", specifier = ">=1.60.0" },
+    { name = "pymilvus", specifier = ">=2.3.0" },
+]
 
 [[package]]
 name = "watchdog"