PyRank
stan-dev

cmdstanpy

CmdStanPy is a lightweight interface to Stan for Python users which provides the necessary objects and functions to compile a Stan program and fit the model to data using CmdStan.
PyPI GitHub Verified repo
No known security advisories. The current version has no OSV.dev malware reports and no critical or high-severity vulnerabilities.

cmdstanpy has 7.9M monthly downloads and 198 GitHub stars. Version 1.3.0 supports Python 3.9+, first published in 2019.

It is actively maintained under a permissive license, last released in Oct 2025.

It is built on top of numpy, pandas and stanio. It is used by 37 tracked packages, including prophet, orbit-ml and kpower-forecast.

Downloads
Day
209.9K
Week
1.5M
Month
7.9M
Stars
198
Forks
83
Issues
26
Version
1.3.0

Package Insights

What's this?
Score breakdown - each component scores 0-100, weighted by percentage
Maintenance
90
Popularity
51
Adoption
60
Community
70
Provenance
100
How the maintenance status was determined
Last commit
8 days ago
Monthly downloads
7,893,209
• Active
Activity within 30 days
Stable
Activity within 31-180 days
Minimal
Activity within 181-365 days, or no activity data
At Risk
No activity for > 365 days, but > 10,000 monthly downloads
Archived
Repository flagged as archived on GitHub
How the popularity category was determined
Monthly downloads
7,893,209
Stars
198
Stars per 1k downloads
0.03
Industry Standard
> 10,000,000 monthly downloads
• Hidden Gem
< 0.5 stars per 1k downloads and > 100,000 monthly downloads
Community Favorite
> 5 stars per 1k downloads
Rising Star
Balanced ratio of stars to downloads
Unknown
Fewer than 1,000 monthly downloads, or no star data
How download momentum is calculated
Week daily avg
220,500
Month daily avg
263,107
Momentum
-16.2%
((week_daily_avg - month_daily_avg) / month_daily_avg) * 100
Python version support tiers
requires_python
>=3.9
Cutting Edge
Minimum supported version is 3.12 or newer
• Modern
Minimum supported version is 3.9, 3.10, or 3.11
Legacy
Supports 3.8 or older (or Python 2)
Unknown
No requires_python specified or unparseable
License categories
License
BSD-3-Clause
• Permissive
MIT, Apache, BSD, ISC, Unlicense, CC0, etc.
Copyleft
GPL, LGPL, AGPL, MPL, EPL, etc.
Proprietary
Commercial, all rights reserved, custom EULAs
Unknown
No license specified, or none of the above match
How the release cadence was determined
Last release
259 days ago
Total releases
45
Releases/year
6.5
Rapid
Last release within 365 days and > 12 releases/year
• Regular
Last release within 365 days
Slow
Last release 366-730 days ago
Stalled
Last release > 730 days ago, or no releases
Unknown
No usable release date available
How contributor risk was determined
Contributors
43
Monthly downloads
7,893,209
High Load
≤ 2 contributors and ≥ 50,000 monthly downloads
Moderate Load
< 10 contributors and ≥ 500,000 monthly downloads
Low Load
< 25 contributors and ≥ 5,000,000 monthly downloads, or sole maintainer with ≥ 10,000 monthly downloads
• Balanced
Enough contributors for the package's popularity
Unknown
No contributor data available
Engagement
74
 
Issue Burden
131.3
per 1k stars
Discussions
35.4
per 1k stars
Fork Ratio
51.8%
contrib / forks
Stale Release
251d
 
PR Velocity
Quiet
 

Weekly Downloads

GitHub Stars

Not all downloads include detailed metadata. Breakdowns reflect the subset that does.

Downloads by OS

Linux 157.0K
Windows 795
macOS 254

Python Versions

3.11
36.7% 54.7K
3.12
34.0% 50.8K
3.10
23.7% 35.4K
3.9
3.5% 5.2K
3.13
2.1% 3.2K

Top Countries

1. US US
107.0K
2. IE IE
10.5K
3. DE DE
6.8K
4. NL NL
6.7K
5. IN IN
5.1K
6. AU AU
3.1K
7. GR GR
3.0K
8. FR FR
2.3K
9. SG SG
2.0K
10. JP JP
1.4K

Package Information

License
BSD-3-Clause
First Release
July 19, 2019
Last Release
8 months ago
Last Commit
1 week ago
Latest Version
1.3.0
Total Releases
45
Contributors
43
Open PRs
3
Archived
No
Author
Stan Dev Team
Python Versions
3
Wheels
py3
Tracking Since
January 6, 2026
Data Updated
July 5, 2026
Data Freshness
Fresh

Links