Make sentence_transformers an optional dependency

examples/amazon_s3_embedding/main.py

@@ -1,3 +1,13 @@
+"""
+This example uses SentenceTransformerEmbed which requires the optional sentence-transformers dependency.
+
+Install with:
+    pip install 'cocoindex[sentence-transformers]'
+
+Or install the dependency directly:
+    pip install sentence-transformers
+"""
+
 from dotenv import load_dotenv
 from psycopg_pool import ConnectionPool
 import cocoindex

examples/code_embedding/main.py

@@ -1,3 +1,13 @@
+"""
+This example uses SentenceTransformerEmbed which requires the optional sentence-transformers dependency.
+
+Install with:
+    pip install 'cocoindex[sentence-transformers]'
+
+Or install the dependency directly:
+    pip install sentence-transformers
+"""
+
 from dotenv import load_dotenv
 from psycopg_pool import ConnectionPool
 from pgvector.psycopg import register_vector

examples/fastapi_server_docker/main.py

@@ -1,3 +1,13 @@
+"""
+This example uses SentenceTransformerEmbed which requires the optional sentence-transformers dependency.
+
+Install with:
+    pip install 'cocoindex[sentence-transformers]'
+
+Or install the dependency directly:
+    pip install sentence-transformers
+"""
+
 import cocoindex
 import uvicorn
 from dotenv import load_dotenv

examples/gdrive_text_embedding/main.py

@@ -1,3 +1,13 @@
+"""
+This example uses SentenceTransformerEmbed which requires the optional sentence-transformers dependency.
+
+Install with:
+    pip install 'cocoindex[sentence-transformers]'
+
+Or install the dependency directly:
+    pip install sentence-transformers
+"""
+
 from dotenv import load_dotenv
 from psycopg_pool import ConnectionPool
 import cocoindex

examples/pdf_embedding/main.py

@@ -1,3 +1,13 @@
+"""
+This example uses SentenceTransformerEmbed which requires the optional sentence-transformers dependency.
+
+Install with:
+    pip install 'cocoindex[sentence-transformers]'
+
+Or install the dependency directly:
+    pip install sentence-transformers
+"""
+
 import cocoindex
 import os
 import tempfile

examples/text_embedding/main.py

@@ -1,3 +1,13 @@
+"""
+This example uses SentenceTransformerEmbed which requires the optional sentence-transformers dependency.
+
+Install with:
+    pip install 'cocoindex[sentence-transformers]'
+
+Or install the dependency directly:
+    pip install sentence-transformers
+"""
+
 from dotenv import load_dotenv
 from psycopg_pool import ConnectionPool
 from pgvector.psycopg import register_vector

examples/text_embedding_qdrant/main.py

@@ -1,3 +1,13 @@
+"""
+This example uses SentenceTransformerEmbed which requires the optional sentence-transformers dependency.
+
+Install with:
+    pip install 'cocoindex[sentence-transformers]'
+
+Or install the dependency directly:
+    pip install sentence-transformers
+"""
+
 from dotenv import load_dotenv
 from qdrant_client import QdrantClient
 import cocoindex

pyproject.toml

@@ -10,7 +10,6 @@ authors = [{ name = "CocoIndex", email = "cocoindex.io@gmail.com" }]
 readme = "README.md"
 requires-python = ">=3.11"
 dependencies = [
-    "sentence-transformers>=3.3.1",
     "click>=8.1.8",
     "rich>=14.0.0",
     "python-dotenv>=1.1.0",
@@ -31,6 +30,7 @@ features = ["pyo3/extension-module"]
 [project.optional-dependencies]
 test = ["pytest"]
 dev = ["ruff", "pre-commit"]
+sentence-transformers = ["sentence-transformers>=3.3.1"]
 
 [tool.mypy]
 python_version = "3.11"

python/cocoindex/functions.py

@@ -12,6 +12,14 @@
 if TYPE_CHECKING:
     import sentence_transformers
 
+# Check if sentence_transformers is available
+try:
+    import sentence_transformers
+
+    _SENTENCE_TRANSFORMERS_AVAILABLE = True
+except ImportError:
+    _SENTENCE_TRANSFORMERS_AVAILABLE = False
+
 
 class ParseJson(op.FunctionSpec):
     """Parse a text into a JSON object."""
@@ -58,6 +66,10 @@ class SentenceTransformerEmbed(op.FunctionSpec):
 
         model: The name of the SentenceTransformer model to use.
         args: Additional arguments to pass to the SentenceTransformer constructor. e.g. {"trust_remote_code": True}
+
+    Note:
+        This function requires the optional sentence-transformers dependency.
+        Install it with: pip install 'cocoindex[sentence-transformers]'
     """
 
     model: str
@@ -72,6 +84,14 @@ class SentenceTransformerEmbedExecutor:
     _model: "sentence_transformers.SentenceTransformer"
 
     def analyze(self, text: Any) -> type:
+        if not _SENTENCE_TRANSFORMERS_AVAILABLE:
+            raise ImportError(
+                "sentence_transformers is required for SentenceTransformerEmbed function. "
+                "Install it with one of these commands:\n"
+                "  pip install 'cocoindex[sentence-transformers]'\n"
+                "  pip install sentence-transformers"
+            )
+
         import sentence_transformers  # pylint: disable=import-outside-toplevel
 
         args = self.spec.args or {}