Public record
Software health reportschema 0.34.0 · metrics 2.10.0 · 2026-09-10 21:23 UTC

python-attrs / cattrs

Composable custom class converters for attrs, dataclasses and friends.

PythonMIT★ 1,051 stars⑂ 156 forkssince Aug 2016View on GitHub ↗
KindLibraryhow this is determined
#attrs#deserialization#serialization

python-attrs/cattrs holds a health index of 94 out of 100, placing it in the Exceptional band. It scores highest on Vitality (88/100) and lowest on AI Readiness (68/100). It was last updated 3 days ago. A single contributor accounts for most of its recent work.

94
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.

94
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 81 is calibrated to 94 on the published index scale (record calibration 2026-08-02).

Ownership

The attrs CabalOrganization · verified domain
74 followers2 public repossince Feb 2017

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

Package ecosystems

RegistryPackageVersionDownloads / moVersionsLast publishTags
PyPIcattrs26.2.049,227,912434 days agoattrsdataclassesserialization

Metrics by category

Vitality

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

88Excellent · 21% of overall

Development activity

86Excellent
How it's scored
36/36Push recency — last push 3 days ago
22.8/36Commit cadence — 33/52 weeks with commits
16.7/18Commit volume — 72 commits in the last year
10/10OpenSSF Scorecard: Maintained — 18 commit(s) and 6 issue activity found in the last 90 days -- score normalized to 10
Inputs used
commits_last_year72
human_commit_share0.93
days_since_last_push3
active_weeks_last_year33

Release discipline

92Excellent
How it's scored
27/27Ships releases — 14 releases published
36/36Release recency — latest release 4 days ago
19.8/27Release cadence — a release every ~82.1 days
0/10OpenSSF Scorecard: Signed-Releases — no data
Inputs used
releases_count14
latest_release_tagv26.2.0
releases_from_tagsno
days_since_latest_release4
mean_days_between_releases82.1
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?

87Excellent · 17% of overall

Popularity & adoption

74Good
How it's scored
49/60Stars — 1,051 stars
18.3/25Forks — 156 forks
6.7/15Watchers — 17 watchers
Inputs used
forks156
stars1,051
watchers17
growth_stateunverified
growth_factor_pct100
growth_unverified_reasonno_history

Community health

93Exceptional
How it's scored
22.5/22.5README
22.5/22.5License — recognized license (MIT)
18/18CONTRIBUTING guide
13.5/13.5Code of conduct
7.2/7.2Issue template
0/6.3PR template
Inputs used
has_readmeyes
has_licenseyes
readme_badges5
has_contributingyes
has_issue_templateyes
has_code_of_conductyes
readme_badge_servicesshields.io
has_pull_request_templateno

Ecosystem adoption (downloads)

100Exceptional
How it's scored
80/80Monthly downloads — 49,227,912 downloads/month across pypi
0/20Registry dependents — not reported by this ecosystem
Inputs used
packagescattrs
dependents—
ecosystemspypi
total_downloads—
monthly_downloads49,227,912
unverified_packages_excluded—
Excluded from scoring (no data or not applicable): Registry dependents. Remaining weights renormalized.

Sustainability & Governance

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

71Good · 23% of overall

Maintainer resilience (bus factor)

38Weak
How it's scored
9/54Bus factor — 1 contributor(s) cover half of all commits
5.1/22.5Commit distribution — top contributor authored 78% of commits
13.5/13.5Contributor breadth — 82 contributors
10/10OpenSSF Scorecard: Contributors — project has 29 contributing companies or organizations
Inputs used
bus_factor1
contributors_sampled82
top_contributor_share0.775

Issue & PR responsiveness

80Excellent
How it's scored
33.9/42Issue resolution — 81% of issues closed
26.1/30PR acceptance — 307/353 decided PRs merged
13/13Newcomer PR acceptance — 3/3 first-time contributors' PRs merged in 30d
7.5/15OpenSSF Scorecard: Code-Review — Found 9/17 approved changesets -- score normalized to 5
Inputs used
merged_prs307
open_issues79
closed_issues333
prs_merged_7d1
prs_decided_7d1
prs_merged_30d5
prs_decided_30d5
issue_closed_ratio0.808
closed_unmerged_prs46
first_time_authors_30d3
first_time_prs_merged_30d3
first_time_prs_decided_30d3

Ownership & stewardship

79Good
How it's scored
30/30Ownership backing — organization-owned
20/20Verified domain
13.5/25Owner reach — 74 followers of python-attrs
15.5/25Track record — 2 public repos, account ~9 yr old
Inputs used
followers74
owner_typeOrganization
is_verifiedyes
owner_loginpython-attrs
public_repos2
account_age_days3,490

Package maintenance

100Exceptional
How it's scored
25/25Published & resolvable — 1 package(s) on pypi
35/35Publish recency — latest publish 4 days ago
20/20Version history — 43 published versions
20/20Not deprecated — active, not deprecated or yanked
Inputs used
packagescattrs
ecosystemspypi
any_deprecatedno
min_days_since_publish4

Engineering Quality

Are baseline engineering and documentation practices in place?

86Excellent · 19% of overall

Engineering practices

84Excellent
How it's scored
24/24CI workflows — 4 workflow(s)
24/24Tests present
16/16Linter config — pyproject.toml ([tool.ruff])
0/9.6Pre-commit hooks
0/6.4.editorconfig
20/20OpenSSF Scorecard: CI-Tests — 18 out of 18 merged PRs checked by a CI test -- score normalized to 10
Inputs used
has_ciyes
has_testsyes
has_editorconfigno
has_linter_configyes
has_precommit_configno

Documentation

90Excellent
How it's scored
30/30README
25/25Documentation directory
15/15Documentation / homepage site — https://catt.rs
10/10Repository description
10/10Topics — 3 topics
0/10Wiki
Inputs used
topicsattrs, deserialization, serialization
has_wikino
homepagehttps://catt.rs
docs_sitehttps://catt.rs
has_readmeyes
has_docs_diryes
has_descriptionyes

Security

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

78Good · 16% of overall

Security posture

73Good
How it's scored
7.5/7.5Binary-Artifacts — no binaries found in the repo
0/7.5Branch-Protection — branch protection not enabled on development/release branches
2.5/2.5CI-Tests — 18 out of 18 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
3.8/7.5Code-Review — Found 9/17 approved changesets -- score normalized to 5
2.5/2.5Contributors — project has 29 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 — 18 commit(s) and 6 issue activity found in the last 90 days -- score normalized to 10
5/5Packaging — packaging workflow detected
5/5Pinned-Dependencies — all dependencies are pinned
5/5SAST — SAST tool is run on all commits
5/5Security-Policy — security policy file detected
0/7.5Signed-Releases — no data
7.5/7.5Token-Permissions — GitHub workflow tokens follow principle of least privilege
0/7.5Vulnerabilities — 17 existing vulnerabilities detected
Inputs used
sourceopenssf_scorecard
checks_evaluated17
scorecard_versionv5.5.0
checks_inconclusive1
scorecard_aggregate7.3
Excluded from scoring (no data or not applicable): Signed-Releases. Remaining weights renormalized.

Dependency advisories

100Exceptional
How it's scored
35/35Direct dependencies free of known advisories — no direct dependency carries a known advisory
25/25Indirect dependencies free of known advisories — no indirect dependency carries a known advisory
0/40No advisories left outstanding — no advisory carries a publication date
Inputs used
sourceosv
advisories0
affected_packages0
assessed_packages2
unassessed_packages0
affected_by_severitynone
direct_affected_packages0
Excluded from scoring (no data or not applicable): No advisories left outstanding. Remaining weights renormalized. Matched the pypi:cattrs@26.2.0 runtime dependency closure — what installing the published package pulls in — 2 packages. Reachability is not analyzed.

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.

68Good · 4% of overall

Agent context & guidance

32At Risk
How it's scored
0/45Agent instructions — no CLAUDE.md / AGENTS.md / editor rules
0/15Machine-readable docs (llms.txt)
32.1/40Legible commit history — 56 of 93 human commits state their intent (structured subject or explanatory body)
Inputs used
has_llms_txtno
llms_txt_url—
legible_history_share0.602
agent_instruction_files—
agent_instruction_max_bytes—

Verify loop (build / test / typecheck)

90Excellent
How it's scored
18/18One-command bootstrap — Justfile, docs/Makefile
22/22Automated tests
11/11Lint / format config — pyproject.toml ([tool.ruff])
11/11Static type checking — src/cattr/py.typed, src/cattrs/py.typed
10/10Reproducible environment — lockfile
0/10Demonstrated agent practice — no agent-authored commits among the last 100
8/8Automated maintenance — 7 of the last 100 commits are automated dependency updates
10/10OpenSSF Scorecard: Pinned-Dependencies — all dependencies are pinned
Inputs used
has_nixno
has_testsyes
lockfilesuv.lock
has_dockerfileno
typed_languageno
bootstrap_filesJustfile, docs/Makefile
has_devcontainerno
has_linter_configyes
typecheck_configssrc/cattr/py.typed, src/cattrs/py.typed
agent_commit_share0
toolchain_manifests—
dependency_bot_commit_share0.07

Code legibility for models

82Excellent
How it's scored
27/45Type-checkable code — Python with type-check config (src/cattr/py.typed, src/cattrs/py.typed)
55/55Manageable file sizes — 0/122 source files over 60KB
Inputs used
primary_languagePython
largest_source_bytes56,581
source_files_sampled122
oversized_source_files0

Key facts

1,051GitHub stars
82contributors
72commits, last 12 months
3days since last push
14releases
1bus factor
79open issues
PyPIpackage ecosystems

Data collection warnings

  • Star history unavailable: GitHub GraphQL error: Resource not accessible by personal access token

More detail

Star and fork history 0 ★ / 156 ⇿
0Stars
156Forks
14Releases

When each star and fork was added, collected from GitHub and bucketed by day. Cumulative growth sits directly above the daily additions it is made of, so the two read against each other: steady organic accretion looks nothing like an abrupt, short-lived burst. Where that difference is measurable, it is reported as growth authenticity.

0408012016015542016-122021-112026-09
Major 0Minor 7Patch 7

Each point covers 9 days.

OpenSSF Scorecard 7.3 / 10
7.3aggregate

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 · 2026-09-10 21:22 UTC

10Binary-Artifactsno binaries found in the repo
0Branch-Protectionbranch protection not enabled on development/release branches
10CI-Tests18 out of 18 merged PRs checked by a CI test -- score normalized to 10
0CII-Best-Practicesno effort to earn an OpenSSF best practices badge detected
5Code-ReviewFound 9/17 approved changesets -- score normalized to 5
10Contributorsproject has 29 contributing companies or organizations
10Dangerous-Workflowno dangerous workflow patterns detected
10Dependency-Update-Toolupdate tool detected
0Fuzzingproject is not fuzzed
10Licenselicense file detected
10Maintained18 commit(s) and 6 issue activity found in the last 90 days -- score normalized to 10
10Packagingpackaging workflow detected
10Pinned-Dependenciesall dependencies are pinned
10SASTSAST tool is run on all commits
10Security-Policysecurity policy file detected
n/aSigned-Releasesno releases found
10Token-PermissionsGitHub workflow tokens follow principle of least privilege
0Vulnerabilities17 existing vulnerabilities detected
Direct dependencies 3
RegistryPackageVersion constraintManifest
PyPIattrs>=25.4.0pyproject.toml
PyPItyping-extensions>=4.14.0pyproject.toml
PyPIexceptiongroup>=1.1.1pyproject.toml
All dependencies 80

Full resolved dependency set from the GitHub dependency graph: 3 direct and 77 indirect (transitive) packages. The transitive closure is complete when the repository commits a lockfile.

RegistryPackageVersionRelation
PyPIattrs25.4.0direct
PyPIexceptiongroup1.3.0direct
PyPItyping-extensions4.14.1direct
PyPIalabaster1.0.0indirect
PyPIanyio4.9.0indirect
PyPIast-serialize0.5.0indirect
PyPIbabel2.17.0indirect
PyPIbeautifulsoup44.13.4indirect
PyPIcbor25.9.0indirect
PyPIcertifi2025.6.15indirect
PyPIcharset-normalizer3.4.2indirect
PyPIclick8.2.1indirect
PyPIcolorama0.4.6indirect
PyPIcoverage7.10.0indirect
PyPIdnspython2.7.0indirect
PyPIdocutils0.21.2indirect
PyPIexecnet2.1.1indirect
PyPIfuro2024.8.6indirect
PyPIh110.16.0indirect
PyPIhypothesis6.135.26indirect
PyPIidna3.10indirect
PyPIimagesize1.4.1indirect
PyPIimmutables0.21indirect
PyPIiniconfig2.1.0indirect
PyPIjinja23.1.6indirect
PyPIlibrt0.11.0indirect
PyPImarkdown-it-py3.0.0indirect
PyPImarkupsafe3.0.2indirect
PyPImdit-py-plugins0.4.2indirect
PyPImdurl0.1.2indirect
PyPImsgpack1.2.1indirect
PyPImsgspec0.21.1indirect
PyPImypy2.1.0indirect
PyPImypy-extensions1.1.0indirect
PyPImyst-parser4.0.1indirect
PyPIorjson3.11.3indirect
PyPIpackaging25.0indirect
PyPIpathspec1.1.1indirect
PyPIpendulum3.1.0indirect
PyPIpluggy1.6.0indirect
PyPIpsutil7.0.0indirect
PyPIpy-cpuinfo9.0.0indirect
PyPIpygments2.20.0indirect
PyPIpymongo4.13.2indirect
PyPIpyperf2.9.0indirect
PyPIpytest9.0.3indirect
PyPIpytest-benchmark5.1.0indirect
PyPIpytest-typing26.3.0indirect
PyPIpytest-xdist3.8.0indirect
PyPIpython-dateutil2.9.0.post0indirect
PyPIpyyaml6.0.2indirect
PyPIrequests2.33.0indirect
PyPIroman-numerals-py3.1.0indirect
PyPIruff0.15.6indirect
PyPIsix1.17.0indirect
PyPIsniffio1.3.1indirect
PyPIsnowballstemmer3.0.1indirect
PyPIsortedcontainers2.4.0indirect
PyPIsoupsieve2.7indirect
PyPIsphinx8.1.3indirect
PyPIsphinx8.2.3indirect
PyPIsphinx-autobuild2024.10.3indirect
PyPIsphinx-basic-ng1.0.0b2indirect
PyPIsphinx-copybutton0.5.2indirect
PyPIsphinxcontrib-applehelp2.0.0indirect
PyPIsphinxcontrib-devhelp2.0.0indirect
PyPIsphinxcontrib-htmlhelp2.1.0indirect
PyPIsphinxcontrib-jsmath1.0.1indirect
PyPIsphinxcontrib-qthelp2.0.0indirect
PyPIsphinxcontrib-serializinghtml2.0.0indirect
PyPIstarlette0.47.1indirect
PyPItomli2.2.1indirect
PyPItomli-w1.2.0indirect
PyPItomlkit0.13.3indirect
PyPItzdata2025.2indirect
PyPIujson5.12.1indirect
PyPIurllib32.5.0indirect
PyPIuvicorn0.35.0indirect
PyPIwatchfiles1.1.0indirect
PyPIwebsockets15.0.1indirect
Dependency advisories 0

Installing pypi:cattrs@26.2.0 pulls in 2 packages, direct and transitive: 0 carry known advisories, of which 0 are direct dependencies.

No known advisories affect the assessed dependencies.

An advisory means the version recorded in the dependency graph falls inside an advisory’s affected range. Reachability is not analysed, and the graph includes development and test pins — a finding may concern tooling rather than shipped software.

Raw JSON report machine-readable

Feedback

Spotted something off in this report, or have thoughts to share? Wrong measurements, missed tooling, ideas, questions — anything is welcome. Every message is read and gets a response.

The message is kept through sign-in.

Related records

Inspected repositories sharing catalogue tags or ecosystems with python-attrs/cattrs. Read them side by side →

94frenck/probatio⚖️ Probatio. A modern, maintained data validation library for Python. Clean-room, MIT-licensed, drop-in reimplementation of voluptuous.Exceptional86Fatal1ty/mashumaroFast and well tested serialization libraryExcellent80rnag/dataclass-wizardSimple, elegant, wizarding tools for interacting with Python's dataclasses.Excellent77ijl/orjsonFast, correct Python JSON library supporting dataclasses, datetimes, and numpyGood96marshmallow-code/marshmallowA lightweight library for converting complex objects to and from simple Python datatypes.Exceptional94foxglove/mcapMCAP is a modular, performant, and serialization-agnostic container file format, useful for pub/sub and robotics applications.Exceptional

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 v0.34.0 — full methodology · metrics wiki.

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