blob: 31d39153de36727d5320da3614226296afd122de [file] [edit]
<!doctype html>
<html lang="en" dir="ltr" class="plugin-enableRedirectsPlugin plugin-id-default" data-has-hydrated="false">
<head>
<meta charset="UTF-8">
<meta name="generator" content="Docusaurus v3.7.0">
<title data-rh="true">Verify AI-written Python with Pyrefly | Pyrefly</title><meta data-rh="true" name="viewport" content="width=device-width,initial-scale=1"><meta data-rh="true" name="twitter:card" content="summary_large_image"><meta data-rh="true" property="og:url" content="https://pyrefly.org/realpython-social1/"><meta data-rh="true" property="og:locale" content="en"><meta data-rh="true" name="docusaurus_locale" content="en"><meta data-rh="true" name="docusaurus_tag" content="default"><meta data-rh="true" name="docsearch:language" content="en"><meta data-rh="true" name="docsearch:docusaurus_tag" content="default"><meta data-rh="true" property="og:title" content="Verify AI-written Python with Pyrefly | Pyrefly"><meta data-rh="true" name="description" content="Catch type bugs in code your AI agent writes. Pyrefly is an open-source Python type checker built in Rust, fast enough to keep up with your agent&#x27;s inference loop."><meta data-rh="true" property="og:description" content="Catch type bugs in code your AI agent writes. Pyrefly is an open-source Python type checker built in Rust, fast enough to keep up with your agent&#x27;s inference loop."><link data-rh="true" rel="canonical" href="https://pyrefly.org/realpython-social1/"><link data-rh="true" rel="alternate" href="https://pyrefly.org/realpython-social1/" hreflang="en"><link data-rh="true" rel="alternate" href="https://pyrefly.org/realpython-social1/" hreflang="x-default"><link rel="alternate" type="application/rss+xml" href="/blog/rss.xml" title="Pyrefly RSS Feed">
<link rel="alternate" type="application/atom+xml" href="/blog/atom.xml" title="Pyrefly Atom Feed">
<link rel="preconnect" href="https://www.google-analytics.com">
<link rel="preconnect" href="https://www.googletagmanager.com">
<script async src="https://www.googletagmanager.com/gtag/js?id=G-GSX14JC495"></script>
<script>function gtag(){dataLayer.push(arguments)}window.dataLayer=window.dataLayer||[],gtag("js",new Date),gtag("config","G-GSX14JC495",{anonymize_ip:!0})</script>
<link rel="stylesheet" href="/stylex.css">
<link rel="icon" href="/img/Pyrefly-Symbol.svg" type="image/svg" sizes="32x32" media="(prefers-color-scheme: light)">
<link rel="icon" href="/img/Pyrefly-Symbol-Invert.svg" type="image/svg" sizes="32x32" media="(prefers-color-scheme: dark)">
<meta property="og:image" content="/img/Pyrefly-Preview-Symbol.png">
<meta property="og:image:width" content="1200">
<meta property="og:image:height" content="630">
<meta property="og:image:type" content="image/png">
<link rel="api-catalog" href="/.well-known/api-catalog" type="application/linkset+json">
<link rel="alternate" type="text/plain" href="/llms.txt" title="LLM-friendly documentation index">
<link rel="alternate" type="text/plain" href="/llms-full.txt" title="Complete documentation content">
<link rel="agent-skills" href="/.well-known/agent-skills/index.json" type="application/json">
<link rel="stylesheet" href="/css/code-block-buttons.css">
<script src="https://buttons.github.io/buttons.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.0/clipboard.min.js"></script>
<script src="/js/code-block-buttons.js"></script>
<script src="/js/gtag-fragment-tracking.js"></script><link rel="stylesheet" href="/assets/css/styles.eb8d0bd5.css">
<script src="/assets/js/runtime~main.f4e774ad.js" defer="defer"></script>
<script src="/assets/js/main.73583540.js" defer="defer"></script>
</head>
<body class="navigation-with-keyboard">
<script>!function(){function t(t){document.documentElement.setAttribute("data-theme",t)}var e=function(){try{return new URLSearchParams(window.location.search).get("docusaurus-theme")}catch(t){}}()||function(){try{return window.localStorage.getItem("theme")}catch(t){}}();t(null!==e?e:"dark")}(),function(){try{const n=new URLSearchParams(window.location.search).entries();for(var[t,e]of n)if(t.startsWith("docusaurus-data-")){var a=t.replace("docusaurus-data-","data-");document.documentElement.setAttribute(a,e)}}catch(t){}}()</script>
<div style="display: none; text-align: center; background-color: white; color: black;" id="internaldocs-banner"></div><div id="__docusaurus"><div role="region" aria-label="Skip to main content"><a class="skipToContent_fXgn" href="#__docusaurus_skipToContent_fallback">Skip to main content</a></div><nav aria-label="Main" class="navbar navbar--fixed-top"><div class="navbar__inner"><div class="navbar__items"><button aria-label="Toggle navigation bar" aria-expanded="false" class="navbar__toggle clean-btn" type="button"><svg width="30" height="30" viewBox="0 0 30 30" aria-hidden="true"><path stroke="currentColor" stroke-linecap="round" stroke-miterlimit="10" stroke-width="2" d="M4 7h22M4 15h22M4 23h22"></path></svg></button><a class="navbar__brand" href="/"><div class="navbar__logo"><img src="/img/Pyrefly-Symbol.svg" alt="Pyrefly Logo" class="themedComponent_mlkZ themedComponent--light_NVdE" height="24" width="24"><img src="/img/Pyrefly-Symbol-Invert.svg" alt="Pyrefly Logo" class="themedComponent_mlkZ themedComponent--dark_xIcU" height="24" width="24"></div><b class="navbar__title text--truncate">Pyrefly</b></a><a class="navbar__item navbar__link" href="/en/docs/">Docs</a><a class="navbar__item navbar__link" href="/en/docs/typing-for-python-developers/">Learn</a><a class="navbar__item navbar__link" href="/sandbox/">Sandbox</a><a class="navbar__item navbar__link" href="/en/docs/installation/">Install</a><a class="navbar__item navbar__link" href="/blog/">Blog</a></div><div class="navbar__items navbar__items--right"><a href="https://github.com/facebook/pyrefly" target="_blank" rel="noopener noreferrer" class="navbar__item navbar__link navbar__icon github__link" aria-label="GitHub"></a><a href="https://discord.gg/Cf7mFQtW7W" target="_blank" rel="noopener noreferrer" class="navbar__item navbar__link navbar__icon discord__link" aria-label="Discord"></a><div class="toggle_vylO colorModeToggle_DEke"><button class="clean-btn toggleButton_gllP toggleButtonDisabled_aARS" type="button" disabled="" title="Switch between dark and light mode (currently dark mode)" aria-label="Switch between dark and light mode (currently dark mode)" aria-live="polite" aria-pressed="true"><svg viewBox="0 0 24 24" width="24" height="24" class="lightToggleIcon_pyhR"><path fill="currentColor" d="M12,9c1.65,0,3,1.35,3,3s-1.35,3-3,3s-3-1.35-3-3S10.35,9,12,9 M12,7c-2.76,0-5,2.24-5,5s2.24,5,5,5s5-2.24,5-5 S14.76,7,12,7L12,7z M2,13l2,0c0.55,0,1-0.45,1-1s-0.45-1-1-1l-2,0c-0.55,0-1,0.45-1,1S1.45,13,2,13z M20,13l2,0c0.55,0,1-0.45,1-1 s-0.45-1-1-1l-2,0c-0.55,0-1,0.45-1,1S19.45,13,20,13z M11,2v2c0,0.55,0.45,1,1,1s1-0.45,1-1V2c0-0.55-0.45-1-1-1S11,1.45,11,2z M11,20v2c0,0.55,0.45,1,1,1s1-0.45,1-1v-2c0-0.55-0.45-1-1-1C11.45,19,11,19.45,11,20z M5.99,4.58c-0.39-0.39-1.03-0.39-1.41,0 c-0.39,0.39-0.39,1.03,0,1.41l1.06,1.06c0.39,0.39,1.03,0.39,1.41,0s0.39-1.03,0-1.41L5.99,4.58z M18.36,16.95 c-0.39-0.39-1.03-0.39-1.41,0c-0.39,0.39-0.39,1.03,0,1.41l1.06,1.06c0.39,0.39,1.03,0.39,1.41,0c0.39-0.39,0.39-1.03,0-1.41 L18.36,16.95z M19.42,5.99c0.39-0.39,0.39-1.03,0-1.41c-0.39-0.39-1.03-0.39-1.41,0l-1.06,1.06c-0.39,0.39-0.39,1.03,0,1.41 s1.03,0.39,1.41,0L19.42,5.99z M7.05,18.36c0.39-0.39,0.39-1.03,0-1.41c-0.39-0.39-1.03-0.39-1.41,0l-1.06,1.06 c-0.39,0.39-0.39,1.03,0,1.41s1.03,0.39,1.41,0L7.05,18.36z"></path></svg><svg viewBox="0 0 24 24" width="24" height="24" class="darkToggleIcon_wfgR"><path fill="currentColor" d="M9.37,5.51C9.19,6.15,9.1,6.82,9.1,7.5c0,4.08,3.32,7.4,7.4,7.4c0.68,0,1.35-0.09,1.99-0.27C17.45,17.19,14.93,19,12,19 c-3.86,0-7-3.14-7-7C5,9.07,6.81,6.55,9.37,5.51z M12,3c-4.97,0-9,4.03-9,9s4.03,9,9,9s9-4.03,9-9c0-0.46-0.04-0.92-0.1-1.36 c-0.98,1.37-2.58,2.26-4.4,2.26c-2.98,0-5.4-2.42-5.4-5.4c0-1.81,0.89-3.42,2.26-4.4C12.92,3.04,12.46,3,12,3L12,3z"></path></svg></button></div><div class="navbarSearchContainer_Bca1"><div class="navbar__search"><span aria-label="expand searchbar" role="button" class="search-icon" tabindex="0"></span><input id="search_input_react" type="search" placeholder="Loading..." aria-label="Search" class="navbar__search-input search-bar" disabled=""></div></div></div></div><div role="presentation" class="navbar-sidebar__backdrop"></div></nav><div id="__docusaurus_skipToContent_fallback" class="main-wrapper mainWrapper_z2l0"><section id="header-section" class="x78zum5 xdt5ytf xl56j7k x6s0dn4 x98rzlu x1n2onr6 x1ybamxr x9i3lb7"><div class="container"><header class="xh8yej3 x5yr21d xb3r6kr xf6mfmo x1q8uoa4 x12ajmao x1qy935m x1eqz52 xiuzu7u xvmahel x8x9d4c xack27t x1159mfc"><div class="xrvj5dj x1o61qjw x1keyc1r x6s0dn4 x1nj45vr xs9t9wa"><div style="opacity:0"><section class="x78zum5 xdt5ytf x6s0dn4 x2b8uid xg01cxk x1wd8k3y x1w2xznu x1ho0ttd"><img src="/img/Pyrefly-Brandmark.svg" alt="Pyrefly Logo" class="x129qt2x xc8tqf8 x1avslx0 themedComponent_mlkZ themedComponent--light_NVdE"><img src="/img/Pyrefly-Brandmark-Invert.svg" alt="Pyrefly Logo" class="x129qt2x xc8tqf8 x1avslx0 themedComponent_mlkZ themedComponent--dark_xIcU"><h1 class="xzfcrpp xat24cr x1u7k74 xiuzu7u x1qf6e5x">Catch type bugs in code your AI agent writes</h1></section></div><div style="opacity:0"><section class="xg01cxk xh3jouh xg9xeqz x1p40xyo"><ol class="xe8uvvx x1cdrkyh x1ghz6dp x1717udv x78zum5 xdt5ytf xj3jsk1"><li class="x1wqpnmw x1n2onr6 x1hi4g37 x1mj4i3h x1hmns74 x1wlytlt x1r4gw3q x1d9ydfu x1nhnfej x9msap3 x1wu5ye1 x86xft9 x1kv3yhc x1tne634 x19afmco xxe6s46"><h2 class="x117nqv4 xhbfen4 x37zpob x1jchvi3">Install Pyrefly</h2><div class="xh8yej3 x78zum5 xdt5ytf x6s0dn4 xl56j7k x1jpgh95 x1p40xyo x1ojkfpl x1hc1fzr x1ihime0 xapusii"><pre class="xznfmru xgv0goc xrrrfcd x1sxouoy xmx98tf x5yr21d x78zum5 xdt5ytf x1dti6c x11qee0y x11gisft xh8yej3 x12oqio5 xiuzu7u x1crhz8b x1anpbxc x1n2onr6 x126k92a xj0a0fe x1jchvi3"><code><span class="x87ps6o">$ </span>pip install pyrefly &amp;&amp; pyrefly init</code><button class="x10l6tqk xndqk7f x1pzoy33 x1gs6z28 xjbqb8w xiuzu7u x1277o0a" title="Copy to clipboard"><svg width="20" height="20" viewBox="340 364 14 15" xmlns="http://www.w3.org/2000/svg"><path fill="currentColor" d="M342 375.974h4v.998h-4v-.998zm5-5.987h-5v.998h5v-.998zm2 2.994v-1.995l-3 2.993 3 2.994v-1.996h5v-1.995h-5zm-4.5-.997H342v.998h2.5v-.997zm-2.5 2.993h2.5v-.998H342v.998zm9 .998h1v1.996c-.016.28-.11.514-.297.702-.187.187-.422.28-.703.296h-10c-.547 0-1-.452-1-.998v-10.976c0-.546.453-.998 1-.998h3c0-1.107.89-1.996 2-1.996 1.11 0 2 .89 2 1.996h3c.547 0 1 .452 1 .998v4.99h-1v-2.995h-10v8.98h10v-1.996zm-9-7.983h8c0-.544-.453-.996-1-.996h-1c-.547 0-1-.453-1-.998 0-.546-.453-.998-1-.998-.547 0-1 .452-1 .998 0 .545-.453.998-1 .998h-1c-.547 0-1 .452-1 .997z" fill-rule="evenodd"></path></svg></button></pre></div><div class="x78zum5 x1q0g3np x1a02dak x883omv xh8yej3 x1anpbxc"><a href="https://marketplace.visualstudio.com/items?itemName=meta.pyrefly" target="_blank" class="x12lumcd xuxw1ft x2kcbxv x12oqio5 x1ilz85p x19fix8x x150bn4r x117nqv4 x1ypdohk x1ng1d19 x2b8uid x14m1sg7 xcs2p6m x14ow2ja x1jchvi3">Get VSCode Extension</a><a href="https://open-vsx.org/extension/meta/pyrefly" target="_blank" class="x12lumcd xuxw1ft x2kcbxv x12oqio5 x1ilz85p xjbqb8w xiuzu7u x117nqv4 x1ypdohk x1ng1d19 x2b8uid x10fs14w xcs2p6m x14ow2ja x1jchvi3">Get OpenVSX Extension</a></div></li><li class="x1wqpnmw x1n2onr6 x1hi4g37 x1mj4i3h x1hmns74 x1wlytlt x1r4gw3q x1d9ydfu x1nhnfej x9msap3 x1wu5ye1 x86xft9 x1kv3yhc x1tne634 x19afmco xxe6s46"><h2 class="x117nqv4 xhbfen4 x37zpob x1jchvi3">Tell your agent to use it</h2><p class="xat24cr x1evy7pa xiuzu7u x1jchvi3">Add a skill file so your agent runs<!-- --> <code>pyrefly check</code> before it calls a task done, or a Stop hook if it needs more convincing.<!-- --> <a href="/blog/pyrefly-agentic-loop" class="x14qql8p x1bvjpef xdnqva9 x1pz6rqt xddl0ns">Read the setup guide</a>.</p></li><li class="x1wqpnmw x1n2onr6 x1hi4g37 x1mj4i3h x1hmns74 x1wlytlt x1r4gw3q x1d9ydfu x1nhnfej x9msap3 x1wu5ye1 x86xft9 x1kv3yhc x1tne634 x19afmco xxe6s46"><h2 class="x117nqv4 xhbfen4 x37zpob x1jchvi3">Let it fix what Pyrefly finds</h2><p class="xat24cr x1evy7pa xiuzu7u x1jchvi3">Errors come back fast and specific enough to act on, so your agent can correct itself and re-check before the code ever reaches you.</p></li></ol></section></div></div><section><li id="firefly" class="x3ct3a4 x16rqkct x19fix8x x170jfvy x1fsd2vl xg01cxk x10l6tqk x15sbw6u x4rx2xt x470at9 xzhg0zl xvxyf3w x1sqp6r9 x1sqc0ei xh8hsg6 x6207ys"></li><li id="firefly" class="x3ct3a4 x16rqkct x19fix8x x170jfvy x1fsd2vl xg01cxk x10l6tqk x15sbw6u x4rx2xt x470at9 xzhg0zl xvxyf3w x1sqp6r9 x1sqc0ei xh8hsg6 x6207ys"></li><li id="firefly" class="x3ct3a4 x16rqkct x19fix8x x170jfvy x1fsd2vl xg01cxk x10l6tqk x15sbw6u x4rx2xt x470at9 xzhg0zl xvxyf3w x1sqp6r9 x1sqc0ei xh8hsg6 x6207ys"></li><li id="firefly" class="x3ct3a4 x16rqkct x19fix8x x170jfvy x1fsd2vl xg01cxk x10l6tqk x15sbw6u x4rx2xt x470at9 xzhg0zl xvxyf3w x1sqp6r9 x1sqc0ei xh8hsg6 x6207ys"></li><li id="firefly" class="x3ct3a4 x16rqkct x19fix8x x170jfvy x1fsd2vl xg01cxk x10l6tqk x15sbw6u x4rx2xt x470at9 xzhg0zl xvxyf3w x1sqp6r9 x1sqc0ei xh8hsg6 x6207ys"></li></section></header></div></section><section id="ide-carousel-section" class="x78zum5 xdt5ytf xl56j7k x6s0dn4 x98rzlu x1n2onr6 x1ybamxr x9i3lb7"><div class="container"><div style="opacity:0"><div class="xpj9qch x18mflkt xn9wirt x1ilyk1c xg01cxk x1wd8k3y x1w2xznu xmx98tf"><div class="container"><h2 class="xab5occ xiuzu7u x1t84w78">Works where<!-- --> <span class="x14qql8p">you or your agent</span> <!-- -->writes Python</h2></div><div class="xb3r6kr xh8yej3 x1uumjh4"><div class="x78zum5 x6s0dn4 xezivpi x11jjemz xp2xewt x1esw782 xa4qsjk x1so62im xlp1x4z x17dzmu4"><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/vscode.svg" alt="VS Code" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/PyCharm.svg" alt="PyCharm" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/Google_Antigravity_Logo_2025.svg" alt="Google Antigravity" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/cursor_logo_light.svg" alt="Cursor" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/windsurf.svg" alt="Windsurf" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/neovim.svg" alt="Neovim" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/vscode.svg" alt="VS Code" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/PyCharm.svg" alt="PyCharm" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/Google_Antigravity_Logo_2025.svg" alt="Google Antigravity" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/cursor_logo_light.svg" alt="Cursor" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/windsurf.svg" alt="Windsurf" class="xwzfr38 x14atkfc"></div><div class="x78zum5 x6s0dn4 xl56j7k xgepmj6 xdq1jza"><img src="/img/neovim.svg" alt="Neovim" class="xwzfr38 x14atkfc"></div></div></div></div></div></div></section><section id="performance-comparison-section" class="x78zum5 xdt5ytf xl56j7k x6s0dn4 x98rzlu x1n2onr6 x1ybamxr x9i3lb7"><div class="container"><div style="opacity:0"><h2 class="x1cl2iem xiuzu7u xab5occ xg01cxk x1qgin71 xg9xeqz x1pjroqt">Performance Comparison</h2></div><div style="opacity:0"><div class="xznfmru xgv0goc xur7f20 xrrrfcd x1sxouoy x5yr21d x78zum5 xdt5ytf x1dti6c x1blgzdm x1cqdni5 xg01cxk x1wd8k3y x1w2xznu xmx98tf"><div class="x78zum5 xl56j7k x8fetqu x1t84w78 xg01cxk xg9xeqz x10a5xub"><button class="xznfmru xgv0goc xur7f20 xrrrfcd x1sxouoy xmx98tf x5yr21d x78zum5 xdt5ytf x1dti6c x11qee0y x174zr50 x1ypdohk x1neyzuf x1jchvi3 x18t7k3x x14qql8p">PyTorch</button><button class="xznfmru xgv0goc xur7f20 xrrrfcd x1sxouoy xmx98tf x5yr21d x78zum5 xdt5ytf x1dti6c x11qee0y x174zr50 x18t7k3x xiuzu7u x1ypdohk x1neyzuf x1jchvi3">Instagram</button></div><div class="xnxx81d xg01cxk xg9xeqz x10a5xub"><div class="x17r0vjz x1os0d8i">Type checking the<!-- --> <a href="https://github.com/pytorch/pytorch" target="_blank" rel="noopener noreferrer" class="x14qql8p xltytc8">PyTorch</a> <!-- -->codebase from scratch.<span class="x1n2onr6 x1rg5ohu xet2fuk"><span class="xfifm61 xiuzu7u x1146j2 xxymvpz"></span><span class="xlshs6z x1ebloo xiuzu7u x2b8uid x1kogg8i x153ncpu xo0htta x10l6tqk x1vjfegm x1a58ea2 x1nrll8i xuuh30 xdzyupr xg01cxk x177bw73 xeaf4i8 x1vvkbs x1jchvi3"><strong>Tested using Macbook</strong><br>(10 cores: 8 performance + 2 efficiency cores, 32 GB RAM)</span></span></div><div><div class="x98rzlu x78zum5 x1o3pxnk" style="margin-bottom:20px"><div><div class="x78zum5 x4jci6i xrostsh"><span class="x1rg5ohu xwsyq91"><strong>Pyrefly</strong></span><span class="x1n2onr6 x1rg5ohu xet2fuk"><span class="xfifm61 xiuzu7u x1146j2 xxymvpz"></span><span class="xlshs6z x1ebloo xiuzu7u x2b8uid x1kogg8i x153ncpu xo0htta x10l6tqk x1vjfegm x1a58ea2 x1nrll8i xuuh30 xdzyupr xg01cxk x177bw73 xeaf4i8 x1vvkbs x1jchvi3"><strong>Command: &quot;pyrefly check&quot;</strong><br>Pyrefly uses as many threads as possible</span></span></div></div><div class="x1i0uq9b x78zum5"><div class="x1iyjqo2 x1wh8b8d x1y1aw1k"><div class="xv4ge2a x174e0gf xh8yej3 xb3r6kr" style="height:80%;width:4.827299209321681%"><div class="x5yr21d x1pjcqnp x10e4vud x1esw782 x19fix8x" style="animation-duration:2.32s;width:0%"></div></div></div><span class="x8x9d4c xxsxjwm x1hr2gdg"><strong>0.0s</strong></span></div></div><div class="x98rzlu x78zum5 x1o3pxnk" style="margin-bottom:20px"><div><div class="x78zum5 x4jci6i xrostsh"><span class="x1rg5ohu xwsyq91"><strong>Pyright</strong></span><span class="x1n2onr6 x1rg5ohu xet2fuk"><span class="xfifm61 xiuzu7u x1146j2 xxymvpz"></span><span class="xlshs6z x1ebloo xiuzu7u x2b8uid x1kogg8i x153ncpu xo0htta x10l6tqk x1vjfegm x1a58ea2 x1nrll8i xuuh30 xdzyupr xg01cxk x177bw73 xeaf4i8 x1vvkbs x1jchvi3"><strong>Command: &quot;pyright --threads=8&quot;</strong><br>8 threads yielded the best performance after testing multiple settings</span></span></div></div><div class="x1i0uq9b x78zum5"><div class="x1iyjqo2 x1wh8b8d x1y1aw1k"><div class="xv4ge2a x174e0gf xh8yej3 xb3r6kr" style="height:80%;width:73.1585518102372%"><div class="x5yr21d x1e1ffwq x1pjcqnp x10e4vud x1esw782" style="animation-duration:35.16s;width:0%"></div></div></div><span class="x8x9d4c xxsxjwm x1hr2gdg"><strong>0.0s</strong></span></div></div><div class="x98rzlu x78zum5 x1o3pxnk"><div><div class="x78zum5 x4jci6i xrostsh"><span class="x1rg5ohu xwsyq91"><strong>MyPy</strong></span><span class="x1n2onr6 x1rg5ohu xet2fuk"><span class="xfifm61 xiuzu7u x1146j2 xxymvpz"></span><span class="xlshs6z x1ebloo xiuzu7u x2b8uid x1kogg8i x153ncpu xo0htta x10l6tqk x1vjfegm x1a58ea2 x1nrll8i xuuh30 xdzyupr xg01cxk x177bw73 xeaf4i8 x1vvkbs x1jchvi3"><strong>Command: &quot;dmypy run&quot;</strong></span></span></div></div><div class="x1i0uq9b x78zum5"><div class="x1iyjqo2 x1wh8b8d x1y1aw1k"><div class="xv4ge2a x174e0gf xh8yej3 xb3r6kr" style="height:80%;width:100%"><div class="x5yr21d x1e1ffwq x1pjcqnp x10e4vud x1esw782" style="animation-duration:48.06s;width:0%"></div></div></div><span class="x8x9d4c xxsxjwm x1hr2gdg"><strong>0.0s</strong></span></div></div></div></div></div></div></div></section><section id="pyrefly-video" class="x78zum5 xdt5ytf xl56j7k x6s0dn4 x98rzlu x1n2onr6 x1ybamxr x9i3lb7 x58caik"><div class="container"><div style="opacity:0"><h2 class="x1cl2iem xiuzu7u xab5occ xg01cxk x1qgin71 xg9xeqz x1pjroqt x2b8uid">See Pyrefly in Action</h2></div><div style="opacity:0"><div class="x1blgzdm xznfmru xgv0goc xur7f20 xrrrfcd x1sxouoy x5yr21d x78zum5 xdt5ytf x1dti6c x1ap80js x19bbpc0 x1cqdni5 xg01cxk x1wd8k3y x1w2xznu xmx98tf"><link rel="preload" href="https://i.ytimg.com/vi/LXaFRKrTJVU/maxresdefault.jpg" as="image"><article class="yt-lite" data-title="Introducing Pyrefly: A new type checker and IDE experience for Python" style="background-image:url(https://i.ytimg.com/vi/LXaFRKrTJVU/maxresdefault.jpg);--aspect-ratio:56.25%"><button type="button" class="lty-playbtn" aria-label="Watch Introducing Pyrefly: A new type checker and IDE experience for Python"></button></article></div></div></div></section></div><footer class="footer"><div class="container container-fluid"><div class="row footer__links"><div class="col footer__col"><div class="footer__title">Community &amp; Support</div><ul class="footer__items clean-list"><li class="footer__item"><a href="https://discord.gg/Cf7mFQtW7W" target="_blank" rel="noopener noreferrer" class="footer__link-item">Join Discord<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://github.com/facebook/pyrefly" target="_blank" rel="noopener noreferrer" class="footer__link-item">Open a Github issue<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://discord.gg/MuFSdD7uCr?event=1389635637090713672" target="_blank" rel="noopener noreferrer" class="footer__link-item">Attend Office Hours<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li></ul></div><div class="col footer__col"><div class="footer__title">Follow Us</div><ul class="footer__items clean-list"><li class="footer__item"><a href="https://x.com/pyrefly_dev" target="_blank" rel="noopener noreferrer" class="footer__link-item">X (Twitter)<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://bsky.app/profile/pyrefly-dev.bsky.social" target="_blank" rel="noopener noreferrer" class="footer__link-item">Bluesky<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://mastodon.social/@pyrefly" target="_blank" rel="noopener noreferrer" class="footer__link-item">Mastodon<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li></ul></div><div class="col footer__col"><div class="footer__title">Legal</div><ul class="footer__items clean-list"><li class="footer__item"><a href="https://opensource.facebook.com/legal/privacy/" target="_blank" rel="noopener noreferrer" class="footer__link-item">Privacy<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://opensource.facebook.com/legal/terms/" target="_blank" rel="noopener noreferrer" class="footer__link-item">Terms<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://opensource.facebook.com/legal/data-policy/" target="_blank" rel="noopener noreferrer" class="footer__link-item">Data Policy<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li><li class="footer__item"><a href="https://opensource.facebook.com/legal/cookie-policy/" target="_blank" rel="noopener noreferrer" class="footer__link-item">Cookie Policy<svg width="13.5" height="13.5" aria-hidden="true" viewBox="0 0 24 24" class="iconExternalLink_nPIU"><path fill="currentColor" d="M21 13v10h-21v-19h12v2h-10v15h17v-8h2zm3-12h-10.988l4.035 4-6.977 7.07 2.828 2.828 6.977-7.07 4.125 4.172v-11z"></path></svg></a></li></ul></div></div><div class="footer__bottom text--center"><div class="footer__copyright">Copyright © 2026 Meta Platforms, Inc. Built with Docusaurus.</div></div></div></footer></div>
</body>
</html>