{"slug": "pyrefly", "name": "Pyrefly", "category": "other", "category_name": "Other software", "description": "", "recommenders": 2, "commenters": 4, "warners": 0, "score": 2.408, "rising": 2.0, "first": "2025-11-30", "latest": "2026-10-24", "why": "Currently we are working on typing our API with Tensor shapes with Pyrefly", "why_is_quote": true, "has_verdict": false, "sentiment": {"recommend": 2, "neutral": 1, "compare": 1, "warn": 0}, "spark": [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1], "listed": false, "loved": [], "caveat": "", "short_quote": "Currently we are working on typing our API with Tensor shapes with Pyrefly", "icon": false, "domain": "pyrefly.org", "github_repo": null, "official_url": "https://pyrefly.org", "pricing": "", "aliases": ["Pyrefly"], "verdict": null, "praise": [{"label": "", "summary": "", "quotes": [{"id": 803546755, "item_id": 50221672, "url": "https://news.ycombinator.com/item?id=50221672", "by": "miki123211", "date": "2026-10-24", "stance": "recommend", "quote": "purely on a type checking front, it's excellent", "excerpt": "I am a Python programmer. I love Astral; I think Ruff is great and uv is life-changing, but I don't actually like ty that much. I want my type checker to check types and to scream at me when it can't. I don't want it to do \"gradual typing\", if it is unsure about what type something is, I want that to be a failure instead of it modeling the unsureness and not showing potential errors. We live in the age of agents, hav", "context": "Python programmer", "use_case": "Python type checking", "switched_from": "", "story": "Bringing uv and ty together"}, {"id": 795251108, "item_id": 49703194, "url": "https://news.ycombinator.com/item?id=49703194", "by": "yeetypete", "date": "2026-09-14", "stance": "recommend", "quote": "Currently we are working on typing our API with Tensor shapes with Pyrefly", "excerpt": "I'm working on vision3d (https://github.com/yeetypete/vision3d) a 3D extension to torchvision. vision3d aims to elegantly extend the well-established torchvision API to 3D object detection tasks. My colleagues and I were not happy with the state of 3D object detection frameworks. Things like mmdetection3d, OpenPCDet, etc. try to do way too much than what's needed for a good 3D ML library. They even came up with their", "context": "", "use_case": "tensor shape type checking", "switched_from": "", "story": "Ask HN: What are you working on? (September 2026)"}]}], "caveats": [], "who": [{"by": "miki123211", "context": "Python programmer", "url": "https://news.ycombinator.com/item?id=50221672", "date": "2026-10-24"}], "tags": [], "use_cases": ["python type checking", "tensor shape type checking"], "compared": [{"slug": "ty", "name": "ty", "co": 3, "switched_from": 0, "switched_to": 1}, {"slug": "mypy", "name": "mypy", "co": 1, "switched_from": 1, "switched_to": 0}, {"slug": "uv", "name": "uv", "co": 3, "switched_from": 0, "switched_to": 0}, {"slug": "ruff", "name": "Ruff", "co": 3, "switched_from": 0, "switched_to": 0}], "makers": [], "threads": [{"url": "https://news.ycombinator.com/item?id=50172962", "title": "Bringing uv and ty together", "mentions": 2}, {"url": "https://news.ycombinator.com/item?id=49686380", "title": "Ask HN: What are you working on? (September 2026)", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=46100637", "title": "Ty \u2013 A fast Python type checker, written in Rust", "mentions": 1}], "sentiment_by_month": {"2025-11": {"neutral": 1}, "2025-12": {}, "2026-01": {}, "2026-02": {}, "2026-03": {}, "2026-04": {}, "2026-05": {}, "2026-06": {}, "2026-07": {}, "2026-08": {}, "2026-09": {"recommend": 1}, "2026-10": {"compare": 1, "recommend": 1}}, "quotes": [{"id": 803546755, "item_id": 50221672, "url": "https://news.ycombinator.com/item?id=50221672", "by": "miki123211", "date": "2026-10-24", "stance": "recommend", "quote": "purely on a type checking front, it's excellent", "excerpt": "I am a Python programmer. I love Astral; I think Ruff is great and uv is life-changing, but I don't actually like ty that much. I want my type checker to check types and to scream at me when it can't. I don't want it to do \"gradual typing\", if it is unsure about what type something is, I want that to be a failure instead of it modeling the unsureness and not showing potential errors. We live in the age of agents, hav", "context": "Python programmer", "use_case": "Python type checking", "switched_from": "", "story": "Bringing uv and ty together"}, {"id": 803521619, "item_id": 50220101, "url": "https://news.ycombinator.com/item?id=50220101", "by": "olive-n", "date": "2026-10-24", "stance": "compare", "quote": "pyrefly seems to me to be the furthest along with support for many common libraries", "excerpt": "The whole python tooling is experiencing kind of a renaissance with new Rust based tools taking over. These days all my project use uv for project management and ruff for linting and formatting. I believe there is no obvious default for type checking yet. I use whatever my IDE provides. So e.g. pylance in VSCode, which is build on pyright. There are currently pretty much 3 projects that I look out for: ty, zuban and ", "context": "", "use_case": "Python type checking", "switched_from": "", "story": "Bringing uv and ty together"}, {"id": 795251108, "item_id": 49703194, "url": "https://news.ycombinator.com/item?id=49703194", "by": "yeetypete", "date": "2026-09-14", "stance": "recommend", "quote": "Currently we are working on typing our API with Tensor shapes with Pyrefly", "excerpt": "I'm working on vision3d (https://github.com/yeetypete/vision3d) a 3D extension to torchvision. vision3d aims to elegantly extend the well-established torchvision API to 3D object detection tasks. My colleagues and I were not happy with the state of 3D object detection frameworks. Things like mmdetection3d, OpenPCDet, etc. try to do way too much than what's needed for a good 3D ML library. They even came up with their", "context": "", "use_case": "tensor shape type checking", "switched_from": "", "story": "Ask HN: What are you working on? (September 2026)"}, {"id": 737627219, "item_id": 46101701, "url": "https://news.ycombinator.com/item?id=46101701", "by": "bbor", "date": "2025-11-30", "stance": "neutral", "quote": "switched a few decently-sized python codebases from MyPy (which I used for years) to PyreFly", "excerpt": "Over the past few months, I've switched a few decently-sized python codebases from MyPy (which I used for years) to PyreFly (because the MyPy LSP ecosystem is somewhere between crumbling and deprecated at this point), and finally to Ty after it left beta this week. I'm now running a fully Astral-ized (rust-ized!) setup: 1. packaging with uv (instead of pip or poetry), 2. type checking with ty (instead of the default ", "context": "", "use_case": "Python type checking", "switched_from": "MyPy", "story": "Ty \u2013 A fast Python type checker, written in Rust"}]}