mypy2,295 reporting projects
Major 2100%
Python library for PyPI
A typed Python library for PyPI in a src layout, built with uv and make. A py.typed marker, strict mypy, pytest with Hypothesis property tests on the newest and oldest supported Python, and a wheel and sdist checked with twine and installed in a clean environment.
What done means
Your agent follows the brief, then runs stacks verify without weakening or skipping checks. What happens next
Declared steps: install, lint, typecheck, test, test-min, build, smoke, readme-filled. View commands
Use this stack
Paste the prompt into the coding agent working on your project.
Uses the stack’s default fragments. Review the brief with your agent.Uses stated defaults and omits deploy, release, and app fragments unless explicitly requested.
View prompt
Use the python-library stack for this project.
1. Run npx @steamfield/stacks show python-library --json and check that it fits the project. If it does not, explain why before changing files.
2. Run npx @steamfield/stacks new python-library and follow the brief it prints.
3. From the generated project directory, run npx @steamfield/stacks verify. Fix failures without weakening or skipping verification steps.
4. Summarize what changed and the verification result. Quote published stats only when they are available, including their interval and sample size.
The stacks docs, written for agents, are at https://stacks.steamfield.io/llms.txt.
Use the python-library stack for a quick local experiment.
1. Run npx @steamfield/stacks show python-library --json and check that it fits the project. If it does not, explain why before changing files.
2. Run npx @steamfield/stacks new python-library --sandbox and follow the brief it prints.
3. From the generated project directory, run npx @steamfield/stacks verify. Fix failures without weakening or skipping verification steps.
4. Summarize what changed and the verification result. Quote published stats only when they are available, including their interval and sample size.
The stacks docs, written for agents, are at https://stacks.steamfield.io/llms.txt.
Or use the terminal
npx @steamfield/stacks new python-librarynpx @steamfield/stacks new python-library --sandbox| Step | Phase | Layer | Command |
|---|---|---|---|
| install | setup | install | make install |
| lint | check | lint | make lint |
| typecheck | check | typecheck | make typecheck |
| test | check | test | make coverage |
| test-min | check | test | make test-min |
| build | check | build | make build |
| smoke | check | test | make smoke |
| readme-filled | check | check | test -s README.md && ! grep -n 'stacks:fill' README.md |
Usage and outcomes
Usage over time
Showing 180 days of history.
History
The 28-day green rate at each weekly observation. Gaps mean the sample was too small to publish.
Shaded band: 95% Wilson interval. Dashed rules: content changes. Missing observations remain gaps.
Stacks projects · 28 days through 4 Nov 2026. Counts rounded to 5.
Data table
| Through | Green rate | Projects | Content change |
|---|---|---|---|
| 5 Jul 2026 | hidden: too few projects | – | – |
| 12 Jul 2026 | 79% (74–84%, n=275) | 390 | – |
| 19 Jul 2026 | 78% (74–81%, n=570) | 830 | – |
| 26 Jul 2026 | 78% (75–80%, n=965) | 1,450 | – |
| 2 Aug 2026 | 77% (75–79%, n=1,465) | 2,205 | – |
| 9 Aug 2026 | 76% (74–78%, n=1,725) | 2,575 | – |
| 16 Aug 2026 | 77% (75–79%, n=2,000) | 2,975 | – |
| 23 Aug 2026 | 77% (75–79%, n=2,270) | 3,285 | – |
| 30 Aug 2026 | 78% (76–79%, n=2,440) | 3,505 | – |
| 6 Sept 2026 | 77% (76–79%, n=2,615) | 3,790 | – |
| 13 Sept 2026 | 77% (76–79%, n=2,765) | 4,005 | – |
| 20 Sept 2026 | 77% (75–78%, n=2,935) | 4,290 | – |
| 27 Sept 2026 | 76% (75–78%, n=3,045) | 4,480 | – |
| 4 Oct 2026 | 76% (75–78%, n=3,270) | 4,780 | – |
| 11 Oct 2026 | 76% (75–77%, n=3,495) | 5,055 | – |
| 18 Oct 2026 | 76% (75–78%, n=3,580) | 5,195 | – |
| 25 Oct 2026 | 76% (75–78%, n=3,740) | 5,435 | – |
| 1 Nov 2026 | 77% (76–79%, n=3,885) | 5,660 | – |
Weekly projects by preset
Non-overlapping seven-day project counts, grouped by the preset used to start the project.
- default
- sandbox
Stacks projects per UTC week through 4 Nov 2026. Published preset counts only; hidden cells are not zero.
Data table
| Week ending | Preset | Projects |
|---|---|---|
| 5 Jul 2026 | default | – |
| 12 Jul 2026 | default | 250 |
| 19 Jul 2026 | default | 285 |
| 26 Jul 2026 | default | 405 |
| 2 Aug 2026 | default | 495 |
| 9 Aug 2026 | default | 485 |
| 16 Aug 2026 | default | 560 |
| 23 Aug 2026 | default | 595 |
| 30 Aug 2026 | default | 625 |
| 6 Sept 2026 | default | 660 |
| 13 Sept 2026 | default | 675 |
| 20 Sept 2026 | default | 795 |
| 27 Sept 2026 | default | 760 |
| 4 Oct 2026 | default | 880 |
| 11 Oct 2026 | default | 870 |
| 18 Oct 2026 | default | 900 |
| 25 Oct 2026 | default | 925 |
| 1 Nov 2026 | default | 1,050 |
| 5 Jul 2026 | sandbox | – |
| 12 Jul 2026 | sandbox | 140 |
| 19 Jul 2026 | sandbox | 155 |
| 26 Jul 2026 | sandbox | 215 |
| 2 Aug 2026 | sandbox | 255 |
| 9 Aug 2026 | sandbox | 275 |
| 16 Aug 2026 | sandbox | 280 |
| 23 Aug 2026 | sandbox | 340 |
| 30 Aug 2026 | sandbox | 345 |
| 6 Sept 2026 | sandbox | 385 |
| 13 Sept 2026 | sandbox | 385 |
| 20 Sept 2026 | sandbox | 420 |
| 27 Sept 2026 | sandbox | 400 |
| 4 Oct 2026 | sandbox | 460 |
| 11 Oct 2026 | sandbox | 465 |
| 18 Oct 2026 | sandbox | 460 |
| 25 Oct 2026 | sandbox | 475 |
| 1 Nov 2026 | sandbox | 520 |
By preset
Green verify outcomes by the preset chosen at scaffold time.
default
76%74–78%, n=2,335
sandbox
81%79–83%, n=1,220
Stacks projects · 28 days through 4 Nov 2026. Counts rounded to 5.
Data table
| Name | Green rate | Projects |
|---|---|---|
| default | 76% (74–78%, n=2,335) | 3,435 |
| sandbox | 81% (79–83%, n=1,220) | 1,780 |
By agent
Within this stack, listed alphabetically. These are project outcomes, not an agent ranking.
claude
79%77–80%, n=1,965
codex
76%73–79%, n=865
cursor
78%74–82%, n=350
none
75%65–82%, n=100
opencode
77%70–82%, n=190
other
82%72–89%, n=80
Stacks projects · 28 days through 4 Nov 2026. Counts rounded to 5.
Data table
| Name | Green rate | Projects |
|---|---|---|
| claude | 79% (77–80%, n=1,965) | 2,900 |
| codex | 76% (73–79%, n=865) | 1,245 |
| cursor | 78% (74–82%, n=350) | 515 |
| none | 75% (65–82%, n=100) | 155 |
| opencode | 77% (70–82%, n=190) | 290 |
| other | 82% (72–89%, n=80) | 115 |
Time to green
Published time summaries on a shared minutes scale. First passing test is a median; 75% reached green by the 75th percentile.
- Verify runs to green
- 1
Stacks projects · 28 days through 4 Nov 2026. Counts rounded to 5.
Data table
| Measure | Time / runs |
|---|---|
| Median to green | 23 minutes |
| 75th percentile | 32 minutes |
| First passing test | 14 minutes |
| Verify runs to green | 1 |
Where it breaks
A run can fail more than one step. Environment failures are shown separately.
test22%
typecheck21%
test-min18%
lint11%
build10%
readme-filled6%
install6%
smoke5%
Environment blocked0%
Share of failed runs before first green. Environment blocked describes the machine, not the stack.
Data table
| Step | Share |
|---|---|
| readme-filled | 6% |
| typecheck | 21% |
| smoke | 5% |
| install | 6% |
| test | 22% |
| test-min | 18% |
| lint | 11% |
| build | 10% |
| Environment blocked | 0% |
What people change
Defaults people keep, and optional fragments they choose to attach.
Default, kept rate
agent-ops92%
git-hooks92%
ci-github92%
Optional, attach rate
rr19%
ce-plugin17%
Share of the window's 5,220 projects. Kept rate is 1 minus the without rate.
Data table
| Fragment | Measure | Share |
|---|---|---|
| agent-ops | Kept | 92% |
| git-hooks | Kept | 92% |
| ci-github | Kept | 92% |
| rr | Attached | 19% |
| ce-plugin | Attached | 17% |
By composition 31 fingerprints
Each row is a distinct fragment composition, with its own sample and content history.
| Composition | Green rate | Seen | Change in life |
|---|---|---|---|
| defaults + rr − agent-ops − git-hooks · 094cbad1 | hidden: too few projects | 19 Jul 2026 – 1 Nov 2026 | None |
| defaults + rr − agent-ops − ci-github · 197f07d8 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin − agent-ops − ci-github · 19cd06e2 | hidden: too few projects | 23 Aug 2026 – 1 Nov 2026 | None |
| defaults + rr − ci-github · 1df4d791 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + rr − agent-ops − ci-github − git-hooks · 39785352 | hidden: too few projects | 30 Aug 2026 – 1 Nov 2026 | None |
| defaults − agent-ops − ci-github · 415ce05b | hidden: too few projects | 19 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin + rr − git-hooks · 536ae840 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults − ci-github − git-hooks · 54403ab0 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults · 5af17c96 | 78% (76–80%, n=2,390) | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin + rr − agent-ops − ci-github · 5e881ab5 | hidden: too few projects | 9 Aug 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin − agent-ops − ci-github − git-hooks · 652b86a8 | hidden: too few projects | 11 Oct 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin + rr · 662c1112 | 78% (70–84%, n=130) | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin + rr − agent-ops · 6bf66eb2 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin + rr − agent-ops − ci-github − git-hooks · 709597d5 | hidden: too few projects | 1 Nov 2026 – 1 Nov 2026 | None |
| defaults − agent-ops · 7e285652 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin − git-hooks · 809f2102 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin − agent-ops − git-hooks · 8328ecdb | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin + rr − ci-github − git-hooks · 94a95d26 | hidden: too few projects | 19 Jul 2026 – 1 Nov 2026 | None |
| defaults − ci-github · 95135af9 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin − agent-ops · a2e300f6 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin − ci-github · a72d71ba | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults − git-hooks · b09d6f06 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + rr − agent-ops · b6b432da | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin − ci-github − git-hooks · b7920e72 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin · bb701945 | 79% (75–82%, n=500) | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + ce-plugin + rr − ci-github · bed894eb | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults − agent-ops − git-hooks · c2ba4e9f | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + rr − ci-github − git-hooks · c7374395 | hidden: too few projects | 19 Jul 2026 – 1 Nov 2026 | None |
| defaults − agent-ops − ci-github − git-hooks · d4ce1ec8 | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + rr − git-hooks · ded3d27f | hidden: too few projects | 12 Jul 2026 – 1 Nov 2026 | None |
| defaults + rr · f50e67e4 | 75% (71–79%, n=535) | 12 Jul 2026 – 1 Nov 2026 | None |
Dependencies in use
Major versions reported by this stack's projects in the 28-day window. Declared dependencies remain listed above.
pytest2,295 reporting projects
Major 9100%
pytest-cov2,295 reporting projects
Major 7100%
pytest-randomly2,295 reporting projects
Major 5100%
pytest-xdist2,295 reporting projects
Major 3100%
ruff2,295 reporting projects
Major 0.17100%
This compares projects; it isn't an effect of the dependency.
Computed 5 Nov 2026, through 4 Nov 2026. Numbers describe stacks projects, not the ecosystem.