chroma-core/chroma · error · ValueError

The open_clip python package is not installed. Please instal

Error message

The open_clip python package is not installed. Please install it with `pip install open-clip-torch`. https://github.com/mlfoundations/open_clip

What it means

OpenCLIPEmbeddingFunction.__init__ does `import open_clip` and converts ImportError into ValueError pointing at `pip install open-clip-torch`. This EF embeds images and text into a shared vector space using mlfoundations' open_clip (default model ViT-B-32, checkpoint laion2b_s34b_b79k), so the package — and its heavy friends torch and pillow — must be installed before construction. The import is deferred so plain chromadb installs stay lightweight.

Source

Thrown at chromadb/utils/embedding_functions/open_clip_embedding_function.py:44

        model_name: str = "ViT-B-32",
        checkpoint: str = "laion2b_s34b_b79k",
        device: Optional[str] = "cpu",
    ) -> None:
        """
        Initialize the OpenCLIPEmbeddingFunction.

        Args:
            model_name (str, optional): The name of the model to use for embeddings.
                Defaults to "ViT-B-32".
            checkpoint (str, optional): The checkpoint to use for the model.
                Defaults to "laion2b_s34b_b79k".
            device (str, optional): The device to use for computation.
                Defaults to "cpu".
        """
        try:
            import open_clip
        except ImportError:
            raise ValueError(
                "The open_clip python package is not installed. Please install it with `pip install open-clip-torch`. https://github.com/mlfoundations/open_clip"
            )

        try:
            self._torch = importlib.import_module("torch")
        except ImportError:
            raise ValueError(
                "The torch python package is not installed. Please install it with `pip install torch`"
            )

        try:
            self._PILImage = importlib.import_module("PIL.Image")
        except ImportError:
            raise ValueError(
                "The PIL python package is not installed. Please install it with `pip install pillow`"
            )

        self.model_name = model_name

View on GitHub (pinned to aecdd12c8a)

Solutions

  1. pip install open-clip-torch (note the package name has hyphens; the import name is open_clip)
  2. Verify in the same interpreter: python -c "import open_clip; print(open_clip.__version__)"
  3. Add open-clip-torch, torch, and pillow to your lockfile together, since this EF requires all three

Example fix

// before
fn = OpenCLIPEmbeddingFunction()  # ValueError: open_clip not installed

// after (shell)
pip install open-clip-torch
// then
fn = OpenCLIPEmbeddingFunction()
Defensive patterns

Strategy: validation

Validate before calling

import importlib.util
missing = [m for m in ("open_clip", "torch", "PIL") if importlib.util.find_spec(m) is None]
if missing:
    raise SystemExit(f"OpenCLIP EF needs: pip install open-clip-torch torch pillow (missing: {missing})")
fn = OpenCLIPEmbeddingFunction()

Try / catch

try:
    fn = OpenCLIPEmbeddingFunction()
except ValueError as e:
    if "open_clip" in str(e):
        raise SystemExit("Run: pip install open-clip-torch") from e
    raise

Prevention

When it happens

Trigger: Constructing OpenCLIPEmbeddingFunction() without `pip install open-clip-torch`; venv/interpreter mismatch (open-clip-torch installed for a different Python); installing `open_clip_torch` under a different name/scope (e.g. only in a notebook kernel's env, not the app's env).

Common situations: Prototyping in a notebook (where it works) then running a script in another env (where it doesn't); Docker images that exclude GPU/CV dependencies to slim down; CI caches that skip optional deps.

Related errors

AI-assisted analysis of chroma-core/chroma@aecdd12c8a (2026-08-16). Data as JSON: /api/errors/50955b82eb1fe540. Report an issue: GitHub.