---

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 and karu bundled; the reader links libcurl and OpenSSL)	core writer + Flat reader	core/
DuckDB (optional)	INSTALL cozip FROM community; LOAD cozip;	SQL over stored files	asterisk-labs/cozip_reader

core/ writes archives and reads Flat manifests through the vendored karu. Python, R and Julia use that library; javascript/ has its own HTTP reader. The optional cozip_reader extension queries stored files with SQL. The C API also supports TACO writing. All follow 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.

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