---

Open a ZIP like a table.

cozip adds a Parquet manifest to an ordinary ZIP and puts a small fixed index at byte 0. A reader fetches the index and manifest first, then requests only the payload bytes it needs.

A cozip remains a valid ZIP file: unzip, zipfile.ZipFile, and ordinary ZIP tools still work.

Example

import tempfile
from pathlib import Path

import numpy as np
import pyarrow as pa
import rasterio
import cozip


# 1. Three tiny GeoTIFFs: all-zeros, all-ones, all-twos. (your dataset)
tmp = Path(tempfile.mkdtemp())
labels = ["zeros", "ones", "twos"]
paths = [tmp / f"{label}.tif" for label in labels]

profile = dict(driver="GTiff", dtype="uint8", count=1, width=64, height=64,
               crs="EPSG:4326", transform=rasterio.Affine.identity())
for v, p in enumerate(paths):
    with rasterio.open(p, "w", **profile) as dst:
        dst.write(np.full((64, 64), v, "uint8"), 1)

# 2. Pack with a table.
archive = str(tmp / "dataset.zip")
cozip.write(archive, pa.table({
    "path":  [str(p) for p in paths],
    "name":  [p.name for p in paths],
    "split": ["train", "val", "train"],
    "label": labels,
}))

# 3. Read manifest
manifest = cozip.read(archive)
for _, row in manifest[manifest["split"] == "train"].iterrows():
    with rasterio.open(row["cozip:location"]) as src:
        print(row["name"], src.read(1).mean())

path says where each file lives on disk. name is how it appears inside the archive. Everything else is optional metadata. The writer adds offset and size; the reader can also add cozip:location, a GDAL VSI path.

Bindings

Language	Install	Role	Docs
Python	pip install cozip	read + write	python/
R	install.packages("cozip", repos = "https://asterisk-labs.r-universe.dev")	read + write	r/
Julia	Pkg.Registry.add("https://github.com/asterisk-labs/AsteriskRegistry"); Pkg.add("Cozip")	read + write	julia/
JavaScript	npm install @asterisk-labs/cozip	reader	javascript/
C	vendor core/ (libzip + zlib bundled, zero system deps)	core writer	core/
C++ / DuckDB	INSTALL cozip FROM community; LOAD cozip;	reader via read_flat()	asterisk-labs/cozip_reader

The C library at core/ is the writer core. Its public API also provides the two-stage TACO layout/write path described in docs/taco-writer-internal.md. Python, R, and Julia use libcozip for layout and ZIP serialization. Two readers live outside that C path: the DuckDB community extension at asterisk-labs/cozip_reader exposes read_flat(url) to SQL, and javascript/ reads HTTP archives in browser and server runtimes. All follow the same SPEC.md.

Spec

See SPEC.md. Any conforming reader handles any conforming writer.

AI agent skill

Install the cozip skill so coding agents know its format rules, binding APIs and TACO writer contract.

npx skills add asterisk-labs/cozip

License

MIT.

Made with ♥ by