zarr-metadata 0.1.1

Spec-defined metadata types for Zarr v2 and v3.

zarr-metadata

Python type definitions for Zarr v2 and v3 metadata.

What this is

A typed-data package: TypedDict definitions and Literal aliases for the JSON shapes specified by the Zarr v2 and Zarr v3 specifications, plus types for zarr-extensions and a few widely-used-but-unspecified entities (e.g. consolidated metadata).

What this is for

These types describe the JSON shape of Zarr metadata. They are intended for libraries that read, write, validate, or transform Zarr metadata. Pair them with a runtime validator like pydantic to check JSON loaded from disk:

import json
from pydantic import TypeAdapter
from zarr_metadata.v3.array import ArrayMetadataV3

with open("zarr.json", "rb") as f:
    raw = json.load(f)

metadata = TypeAdapter(ArrayMetadataV3).validate_python(raw)

What this is not

• Not a parser or builder. There are no make_array_metadata(...) factories — that surface belongs to consumer libraries.
• Not a runtime validator on its own. Pair with pydantic, msgspec, or similar to enforce shapes at decode time.

Even with a runtime validator, these types only describe structural shape — they will not flag semantically invalid metadata, like a 3D v3 array whose dimension_names has 4 entries instead of 3. That's a job for downstream validator routines.

Scope

At minimum, this library supports what Zarr-Python needs: the complete Zarr v2 and v3 specs, consolidated metadata, and a subset of the metadata defined in zarr-extensions. We are generally open to contributions that add types for Zarr metadata with a published spec.

License

MIT