Public record
Software health reportschema 0.12.0 · metrics 2.10.0 · 2026-07-18 14:05 UTC

zarr-developers / zarr-python

An implementation of chunked, compressed, N-dimensional arrays for Python.

PythonMIT★ 2,021 stars⑂ 429 forkssince Dec 2015View on GitHub ↗
KindLibraryhow this is determined
#zarr#ndimensional-arrays#compressed#python

zarr-developers/zarr-python holds a health index of 98 out of 100, placing it in the Exceptional band. It scores highest on Vitality (99/100) and lowest on AI Readiness (58/100). It was last updated 1 day ago. 3 contributors account for most of its recent work.

98
overall / 100
Exceptional

Software health index

Metrics are grouped into weighted categories on one standardized 1–100 scale. Overall starts as their weighted mean, calibrated against the distribution of the public record so bands carry percentile meaning; when public evidence triggers the High-Risk Jurisdiction Policy, the rating is adjusted and receives an At Risk ceiling of 34.

98
Exceptional93-100The record's top tier (≈ top 5%); essentially all checked criteria met
Excellent80-92Strong across the board; minor gaps
Good65-79Healthy; gaps are limited and manageable
Moderate50-64Acceptable with notable gaps; review recommended
Weak35-49Material weaknesses across several areas
At Risk20-34Significant weaknesses; adoption warrants caution
Critical1-19Severe problems (abandoned, single-maintainer, no hygiene)
VitalityCommunity &AdoptionSustainability &GovernanceEngineeringQualitySecurityAI Readiness

Score profile

Each axis is a category. The shape matters more than the average — a healthy subject fills the whole shape, while a spike-and-crater profile means strength in one dimension is masking risk in another.

The weighted overall 86 is calibrated to 98 on the published index scale (record calibration 2026-08-02).

Ownership

Zarr DevelopersOrganization
219 followers44 public repossince Jan 2018

This repository is backed by an organization — shared, accountable stewardship that can outlive any single maintainer.

Package ecosystems

RegistryPackageVersionDownloads / moVersionsLast publishTags
PyPIzarr3.2.1-11674 days agopythoncompressedndimensional-arrayszarr

Metrics by category

Vitality

Is the project alive — is code being written and are releases shipping?

99Exceptional · 21% of overall

Development activity

98Exceptional
How it's scored
36/36Push recency — last push 1 days ago
33.9/36Commit cadence — 49/52 weeks with commits
18/18Commit volume — 366 commits in the last year
10/10OpenSSF Scorecard: Maintained — 30 commit(s) and 3 issue activity found in the last 90 days -- score normalized to 10
Inputs used
commits_last_year366
human_commit_share—
days_since_last_push1
active_weeks_last_year49

Release discipline

100Exceptional
How it's scored
27/27Ships releases — 100 releases published
36/36Release recency — latest release 74 days ago
27/27Release cadence — a release every ~32.7 days
0/10OpenSSF Scorecard: Signed-Releases — no data
Inputs used
releases_count100
latest_release_tagv3.2.1
releases_from_tagsno
days_since_latest_release74
mean_days_between_releases32.7
Excluded from scoring (no data or not applicable): OpenSSF Scorecard: Signed-Releases. Remaining weights renormalized.

Community & Adoption

Does the project have users, downloads, attention, and a welcoming setup for contributors?

88Excellent · 17% of overall

Popularity & adoption

84Excellent
How it's scored
53.6/60Stars — 2,021 stars
21.9/25Forks — 429 forks
8.8/15Watchers — 40 watchers
Inputs used
forks429
stars2,021
watchers40
growth_stateunverified
growth_factor_pct100
growth_unverified_reasonno_history

Community health

92Excellent
How it's scored
22.5/22.5README
22.5/22.5License — recognized license (MIT)
18/18CONTRIBUTING guide
13.5/13.5Code of conduct
0/7.2Issue template
6.3/6.3PR template
Inputs used
has_readmeyes
has_licenseyes
readme_badges—
has_contributingyes
has_issue_templateno
has_code_of_conductyes
readme_badge_services—
has_pull_request_templateyes

Sustainability & Governance

Will the project survive its people — bus factor, responsiveness, who backs it, and package upkeep?

82Excellent · 23% of overall

Maintainer resilience (bus factor)

74Good
How it's scored
36/54Bus factor — 3 contributor(s) cover half of all commits
14.9/22.5Commit distribution — top contributor authored 34% of commits
13.5/13.5Contributor breadth — 100 contributors
10/10OpenSSF Scorecard: Contributors — project has 139 contributing companies or organizations
Inputs used
bus_factor3
contributors_sampled100
top_contributor_share0.337

Issue & PR responsiveness

73Good
How it's scored
31.2/42Issue resolution — 74% of issues closed
23.7/30PR acceptance — 1,844/2,339 decided PRs merged
0/13Newcomer PR acceptance — no first-time contributor's PR decided in 30d
9/15OpenSSF Scorecard: Code-Review — Found 15/24 approved changesets -- score normalized to 6
Inputs used
merged_prs1,844
open_issues390
closed_issues1,123
prs_merged_7d—
prs_decided_7d—
prs_merged_30d—
prs_decided_30d—
issue_closed_ratio0.742
closed_unmerged_prs495
first_time_authors_30d—
first_time_prs_merged_30d—
first_time_prs_decided_30d—
Excluded from scoring (no data or not applicable): Newcomer PR acceptance. Remaining weights renormalized.

Ownership & stewardship

88Excellent
How it's scored
30/30Ownership backing — organization-owned
0/20Verified domain — verified-domain status not read for this organization
16.8/25Owner reach — 219 followers of zarr-developers
24/25Track record — 44 public repos, account ~8 yr old
Inputs used
followers219
owner_typeOrganization
is_verified—
owner_loginzarr-developers
public_repos44
account_age_days3,118
Excluded from scoring (no data or not applicable): Verified domain. Remaining weights renormalized.

Package maintenance

100Exceptional
How it's scored
25/25Published & resolvable — 1 package(s) on pypi
35/35Publish recency — latest publish 74 days ago
20/20Version history — 116 published versions
20/20Not deprecated — active, not deprecated or yanked
Inputs used
packageszarr
ecosystemspypi
any_deprecatedno
min_days_since_publish74

Engineering Quality

Are baseline engineering and documentation practices in place?

92Excellent · 19% of overall

Engineering practices

94Exceptional
How it's scored
24/24CI workflows — 16 workflow(s)
24/24Tests present
16/16Linter config
9.6/9.6Pre-commit hooks
0/6.4.editorconfig
20/20OpenSSF Scorecard: CI-Tests — 30 out of 30 merged PRs checked by a CI test -- score normalized to 10
Inputs used
has_ciyes
has_testsyes
has_editorconfigno
has_linter_configyes
has_precommit_configyes

Documentation

90Excellent
How it's scored
30/30README
25/25Documentation directory
15/15Documentation / homepage site — https://zarr.readthedocs.io
10/10Repository description
10/10Topics — 4 topics
0/10Wiki
Inputs used
topicszarr, ndimensional-arrays, compressed, python
has_wikino
homepagehttps://zarr.readthedocs.io
docs_sitehttps://zarr.readthedocs.io
has_readmeyes
has_docs_diryes
has_descriptionyes

Security

Are visible security and supply-chain practices strong, without unresolved high-risk jurisdiction exposure?

70Good · 16% of overall

Security posture

70Good
How it's scored
7.5/7.5Binary-Artifacts — no binaries found in the repo
0/7.5Branch-Protection — no data
2.5/2.5CI-Tests — 30 out of 30 merged PRs checked by a CI test -- score normalized to 10
0/2.5CII-Best-Practices — no effort to earn an OpenSSF best practices badge detected
4.5/7.5Code-Review — Found 15/24 approved changesets -- score normalized to 6
2.5/2.5Contributors — project has 139 contributing companies or organizations
10/10Dangerous-Workflow — no dangerous workflow patterns detected
7.5/7.5Dependency-Update-Tool — update tool detected
0/5Fuzzing — project is not fuzzed
2.5/2.5License — license file detected
7.5/7.5Maintained — 30 commit(s) and 3 issue activity found in the last 90 days -- score normalized to 10
5/5Packaging — packaging workflow detected
4.5/5Pinned-Dependencies — dependency not pinned by hash detected -- score normalized to 9
1.5/5SAST — SAST tool is not run on all commits -- score normalized to 3
0/5Security-Policy — security policy file not detected
0/7.5Signed-Releases — no data
6.8/7.5Token-Permissions — detected GitHub workflow tokens with excessive permissions
0.8/7.5Vulnerabilities — 9 existing vulnerabilities detected
Inputs used
sourceopenssf_scorecard
checks_evaluated16
scorecard_versionv5.5.0
checks_inconclusive2
scorecard_aggregate7
Excluded from scoring (no data or not applicable): Branch-Protection, Signed-Releases. Remaining weights renormalized.

AI Readiness

How well is the repo equipped to be developed and maintained with AI coding agents? Carries a deliberately small weight (4%): agent tooling is a real maintenance signal, but a repository with none can still reach 100/100.

58Moderate · 4% of overall

Agent context & guidance

1Critical
How it's scored
0/45Agent instructions — no CLAUDE.md / AGENTS.md / editor rules
0/15Machine-readable docs (llms.txt)
0/40Legible commit history — no data
Inputs used
has_llms_txtno
llms_txt_url—
legible_history_share—
agent_instruction_files—
agent_instruction_max_bytes—
Excluded from scoring (no data or not applicable): Legible commit history. Remaining weights renormalized.

Verify loop (build / test / typecheck)

76Good
How it's scored
0/18One-command bootstrap
22/22Automated tests
11/11Lint / format config
11/11Static type checking — packages/zarr-metadata/src/zarr_metadata/py.typed, src/zarr/py.typed
10/10Reproducible environment — lockfile
0/10Demonstrated agent practice — no data
5/8Automated maintenance — dependency automation configured, none observed in the sampled commits
9/10OpenSSF Scorecard: Pinned-Dependencies — dependency not pinned by hash detected -- score normalized to 9
Inputs used
has_nixno
has_testsyes
lockfilesuv.lock
has_dockerfileno
typed_languageno
bootstrap_files—
has_devcontainerno
has_linter_configyes
typecheck_configspackages/zarr-metadata/src/zarr_metadata/py.typed, src/zarr/py.typed
agent_commit_share—
toolchain_manifests—
dependency_bot_commit_share0
Excluded from scoring (no data or not applicable): Demonstrated agent practice. Remaining weights renormalized.

Code legibility for models

81Excellent
How it's scored
27/45Type-checkable code — Python with type-check config (packages/zarr-metadata/src/zarr_metadata/py.typed, src/zarr/py.typed)
53.7/55Manageable file sizes — 8/341 source files over 60KB
Inputs used
primary_languagePython
largest_source_bytes213,376
source_files_sampled341
oversized_source_files8

Machine-readable interfaces

100Exceptional
How it's scored
0/40API schema (OpenAPI/GraphQL/proto) — not applicable to this kind of software
0/20MCP server — not applicable to this kind of software
40/40Runnable examples — examples
Inputs used
example_dirsexamples
has_mcp_signalno
api_schema_files—
interfaces_expected_of—
Excluded from scoring (no data or not applicable): API schema (OpenAPI/GraphQL/proto), MCP server. Remaining weights renormalized.

Key facts

2,021GitHub stars
100contributors
366commits, last 12 months
1days since last push
100releases
3bus factor
390open issues
PyPIpackage ecosystems

More detail

OpenSSF Scorecard 7.0 / 10
7.0aggregate

Independent, tool-agnostic security assessment from the open-source OpenSSF Scorecard. Each check rewards a security practice, not a specific vendor's tool. Checks Scorecard could not determine are marked n/a and excluded from the security score (never counted as zero).Scorecard v5.5.0 · 2026-07-18 14:04 UTC

10Binary-Artifactsno binaries found in the repo
n/aBranch-Protectioninternal error: error during branchesHandler.setup: internal error: some github tokens can't read classic branch protection rules: https://github.com/ossf/scorecard-action/blob/main/docs/authentication/fine-grained-auth-token.md
10CI-Tests30 out of 30 merged PRs checked by a CI test -- score normalized to 10
0CII-Best-Practicesno effort to earn an OpenSSF best practices badge detected
6Code-ReviewFound 15/24 approved changesets -- score normalized to 6
10Contributorsproject has 139 contributing companies or organizations
10Dangerous-Workflowno dangerous workflow patterns detected
10Dependency-Update-Toolupdate tool detected
0Fuzzingproject is not fuzzed
10Licenselicense file detected
10Maintained30 commit(s) and 3 issue activity found in the last 90 days -- score normalized to 10
10Packagingpackaging workflow detected
9Pinned-Dependenciesdependency not pinned by hash detected -- score normalized to 9
3SASTSAST tool is not run on all commits -- score normalized to 3
0Security-Policysecurity policy file not detected
n/aSigned-Releasesno releases found
9Token-Permissionsdetected GitHub workflow tokens with excessive permissions
1Vulnerabilities9 existing vulnerabilities detected
Direct dependencies 6
RegistryPackageVersion constraintManifest
PyPIpackaging>=22.0pyproject.toml
PyPInumpy>=2pyproject.toml
PyPInumcodecs>=0.14pyproject.toml
PyPIgoogle-crc32c>=1.5pyproject.toml
PyPItyping_extensions>=4.14pyproject.toml
PyPIdonfig>=0.8pyproject.toml
All dependencies 206

Full resolved dependency set from the GitHub dependency graph: 14 direct and 192 indirect (transitive) packages. The transitive closure is complete when the repository commits a lockfile.

RegistryPackageVersionRelation
PyPIdonfig—direct
PyPIdonfig0.8.1.post1direct
PyPIgoogle-crc32c—direct
PyPIgoogle-crc32c1.8.0direct
PyPInumcodecs—direct
PyPInumcodecs0.12.1direct
PyPInumcodecs0.16.5direct
PyPInumpy—direct
PyPInumpy1.26.4direct
PyPInumpy2.5.0direct
PyPIpackaging—direct
PyPIpackaging26.2direct
PyPItyping-extensions—direct
PyPItyping-extensions4.16.0direct
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PyPIcffi2.0.0indirect
PyPIcfn-lint1.51.0indirect
PyPIcharset-normalizer3.4.7indirect
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PyPIcoverage—indirect
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PyPIfsspec—indirect
PyPIfsspec2023.12.2indirect
PyPIfsspec2026.6.0indirect
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PyPIhatchling—indirect
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PyPIimagesize2.0.0indirect
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PyPIjmespath1.1.0indirect
PyPIjoserfc1.6.8indirect
PyPIjsonpatch1.33indirect
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PyPIjsonpointer3.1.1indirect
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PyPIjsonschema-specifications2025.9.1indirect
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PyPImergedeep1.3.4indirect
PyPImike—indirect
PyPImike2.2.0indirect
PyPImkdocs—indirect
PyPImkdocs1.6.1indirect
PyPImkdocs-autorefs1.4.4indirect
PyPImkdocs-get-deps0.2.2indirect
PyPImkdocs-jupyter—indirect
PyPImkdocs-material—indirect
PyPImkdocs-material9.7.6indirect
PyPImkdocs-material-extensions1.3.1indirect
PyPImkdocs-redirects—indirect
PyPImkdocs-redirects1.2.3indirect
PyPImkdocstrings—indirect
PyPImkdocstrings1.0.4indirect
PyPImkdocstrings-python—indirect
PyPImkdocstrings-python2.0.5indirect
PyPImoto—indirect
PyPImoto5.2.2indirect
PyPImpmath1.3.0indirect
PyPImsgpack1.2.1indirect
PyPImsgpack-python0.5.6indirect
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PyPImypy2.1.0indirect
PyPImypy-extensions1.1.0indirect
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PyPInumpydoc1.10.0indirect
PyPIobstore—indirect
PyPIobstore0.11.0indirect
PyPIopenapi-schema-validator0.8.1indirect
PyPIopenapi-spec-validator0.8.5indirect
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PyPIpathlib-abc0.5.2indirect
PyPIpathspec1.1.1indirect
PyPIpillow12.2.0indirect
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PyPIproperdocs1.6.7indirect
PyPIpy-cpuinfo9.0.0indirect
PyPIpy-partiql-parser0.6.3indirect
PyPIpycparser3.0indirect
PyPIpydantic—indirect
PyPIpydantic2.12.5indirect
PyPIpydantic-core2.41.5indirect
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PyPIpygments-ansi-color0.3.0indirect
PyPIpymdown-extensions10.21.3indirect
PyPIpymongo4.6.3indirect
PyPIpyparsing3.3.2indirect
PyPIpytest8.1.1indirect
PyPIpytest9.1.1indirect
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PyPIpytest-asyncio1.4.0indirect
PyPIpytest-benchmark5.2.3indirect
PyPIpytest-codspeed5.0.3indirect
PyPIpytest-cov5.0.0indirect
PyPIpytest-cov7.1.0indirect
PyPIpytest-doctestplus1.2.1indirect
PyPIpytest-timeout2.3.1indirect
PyPIpytest-xdist3.8.0indirect
PyPIpython-dateutil2.9.0.post0indirect
PyPIpython-dotenv1.2.2indirect
PyPIpywin32311indirect
PyPIpyyaml6.0.3indirect
PyPIpyyaml-env-tag1.1indirect
PyPIredis5.0.4indirect
PyPIreferencing0.37.0indirect
PyPIregex2026.5.9indirect
PyPIrequests2.34.2indirect
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PyPIrfc3339-validator0.1.4indirect
PyPIrich15.0.0indirect
PyPIroman-numerals4.1.0indirect
PyPIrpds-py0.30.0indirect
PyPIruff0.15.20indirect
PyPIs3fs—indirect
PyPIs3fs2023.12.2indirect
PyPIs3fs2026.6.0indirect
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PyPIsetuptools82.0.1indirect
PyPIsetuptools-scm8.0.4indirect
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PyPIsix1.17.0indirect
PyPIsnowballstemmer3.0.1indirect
PyPIsortedcontainers2.4.0indirect
PyPIsphinx9.1.0indirect
PyPIsphinxcontrib-applehelp2.0.0indirect
PyPIsphinxcontrib-devhelp2.0.0indirect
PyPIsphinxcontrib-htmlhelp2.1.0indirect
PyPIsphinxcontrib-jsmath1.0.1indirect
PyPIsphinxcontrib-qthelp2.0.0indirect
PyPIsphinxcontrib-serializinghtml2.0.0indirect
PyPIsympy1.14.0indirect
PyPItinycss21.4.0indirect
PyPItomlkit0.15.0indirect
PyPItowncrier25.8.0indirect
PyPItyper0.26.8indirect
PyPItypes-redis—indirect
PyPItypes-setuptools—indirect
PyPItyping-inspection0.4.2indirect
PyPIuniversal-pathlib0.3.10indirect
PyPIurllib32.7.0indirect
PyPIuv0.11.26indirect
PyPIverspec0.1.0indirect
PyPIwatchdog6.0.0indirect
PyPIwebencodings0.5.1indirect
PyPIwerkzeug3.1.8indirect
PyPIwrapt2.1.2indirect
PyPIxmltodict1.0.4indirect
PyPIyarl1.23.0indirect
Raw JSON report machine-readable

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Scores are signals, not warranties. They reflect publicly visible practices on GitHub — not a code audit, and not a security guarantee.

Missing data is excluded and weights renormalized, never scored as zero. Methodology is versioned and open: metrics v2.10.0, schema v0.12.0 — full methodology · metrics wiki.

How one result sits in the wider record: aggregate statistics — PyPI.