BranchesTags

Repository files navigation

WebContainer API Starter

WebContainer API is a browser-based runtime for executing Node.js applications and operating system commands. It enables you to build applications that previously required a server running.

WebContainer API is perfect for building interactive coding experiences. Among its most common use cases are production-grade IDEs, programming tutorials, or employee onboarding platforms.

How To

For an up-to-date documentation, please refer to our documentation.

Cross-Origin Isolation

WebContainer requiresSharedArrayBuffer to function. In turn, this requires your website to be cross-origin isolated. Among other things, the root document must be served with:

Cross-Origin-Embedder-Policy: require-corp
Cross-Origin-Opener-Policy: same-origin

You can check our article on the subject and our docs on browser support for more details.

Serve over HTTPS

Please note that your deployed page must be served over HTTPS. This is not necessary when developing locally, as localhost is exempt from some browser restrictions, but there is no way around it once you deploy to production.

Demo

Check the WebContainer API demo app.

Here's an example main.ts file:

import{WebContainer}from"@webcontainer/api";constfiles: FileSystemTree={"index.js": {file: {contents: "",},},};letwebcontainer: WebContainer;// add a textarea (the editor) and an iframe (a preview window) to the documentdocument.querySelector("#app").innerHTML=` <div class="container"> <div class="editor"> <textarea>I am a textarea</textarea> </div> <div class="preview"> <iframe></iframe> </div> </div>`;// the editorconsttextarea=document.querySelector("textarea");// the preview windowconstiframe=document.querySelector("iframe");window.addEventListener("load",async()=>{textarea.value=files["index.js"].file.contents;textarea.addEventListener("input",(event)=>{constcontent=event.currentTarget.value;webcontainer.fs.writeFile("/index.js",content);});// call only oncewebcontainer=awaitWebContainer.boot();awaitwebcontainer.mount(files);constexitCode=awaitinstallDependencies();if(exitCode!==0){thrownewError("Installation failed");}startDevServer();});asyncfunctioninstallDependencies(){// install dependenciesconstinstallProcess=awaitwebcontainer.spawn("npm",["install"]);installProcess.output.pipeTo(newWritableStream({write(data){console.log(data);},}));// wait for install command to exitreturninstallProcess.exit;}asyncfunctionstartDevServer(){// run `npm run start` to start the express appawaitwebcontainer.spawn("npm",["run","start"]);// wait for `server-ready` eventwebcontainer.on("server-ready",(port,url)=>{iframe.src=url;});}

Troubleshooting

Cookie blockers, either from third-party addons or built-in into the browser, can prevent WebContainer from running correctly. Check the on('error') event and our docs.

To troubleshoot other problems, check the Troubleshooting page in our docs.

License

Copyright 2023 StackBlitz, Inc.

About

No description, website, or topics provided.

Resources

Readme
Activity
Custom properties

Stars

115 stars

Watchers

10 watching

Forks

94 forks
Report repository

Releases

Packages

Used by

Contributors

Languages

, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
BranchesTags
Repository files navigation
WebContainer API Starter
WebContainer API is a browser-based runtime for executing Node.js applications and operating system commands. It enables you to build applications that previously required a server running.
WebContainer API is perfect for building interactive coding experiences. Among its most common use cases are production-grade IDEs, programming tutorials, or employee onboarding platforms.
How To
For an up-to-date documentation, please refer to our documentation.
Cross-Origin Isolation
WebContainer requiresSharedArrayBuffer to function. In turn, this requires your website to be cross-origin isolated. Among other things, the root document must be served with:
Cross-Origin-Embedder-Policy: require-corp
Cross-Origin-Opener-Policy: same-origin

You can check our article on the subject and our docs on browser support for more details.
Serve over HTTPS
Please note that your deployed page must be served over HTTPS. This is not necessary when developing locally, as localhost is exempt from some browser restrictions, but there is no way around it once you deploy to production.
Demo
Check the WebContainer API demo app.
Here's an example main.ts file:
import{WebContainer}from"@webcontainer/api";constfiles: FileSystemTree={"index.js": {file: {contents: "",},},};letwebcontainer: WebContainer;// add a textarea (the editor) and an iframe (a preview window) to the documentdocument.querySelector("#app").innerHTML=` <div class="container"> <div class="editor"> <textarea>I am a textarea</textarea> </div> <div class="preview"> <iframe></iframe> </div> </div>`;// the editorconsttextarea=document.querySelector("textarea");// the preview windowconstiframe=document.querySelector("iframe");window.addEventListener("load",async()=>{textarea.value=files["index.js"].file.contents;textarea.addEventListener("input",(event)=>{constcontent=event.currentTarget.value;webcontainer.fs.writeFile("/index.js",content);});// call only oncewebcontainer=awaitWebContainer.boot();awaitwebcontainer.mount(files);constexitCode=awaitinstallDependencies();if(exitCode!==0){thrownewError("Installation failed");}startDevServer();});asyncfunctioninstallDependencies(){// install dependenciesconstinstallProcess=awaitwebcontainer.spawn("npm",["install"]);installProcess.output.pipeTo(newWritableStream({write(data){console.log(data);},}));// wait for install command to exitreturninstallProcess.exit;}asyncfunctionstartDevServer(){// run `npm run start` to start the express appawaitwebcontainer.spawn("npm",["run","start"]);// wait for `server-ready` eventwebcontainer.on("server-ready",(port,url)=>{iframe.src=url;});}
Troubleshooting
Cookie blockers, either from third-party addons or built-in into the browser, can prevent WebContainer from running correctly. Check the on('error') event and our docs.
To troubleshoot other problems, check the Troubleshooting page in our docs.
License
Copyright 2023 StackBlitz, Inc.
About
No description, website, or topics provided.
Resources
Readme
Activity
Custom properties
Stars
115 stars
Watchers
10 watching
Forks
94 forks
Report repository
Releases
Packages
Used by
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
WebContainer API Starter
WebContainer API is a browser-based runtime for executing Node.js applications and operating system commands. It enables you to build applications that previously required a server running.
WebContainer API is perfect for building interactive coding experiences. Among its most common use cases are production-grade IDEs, programming tutorials, or employee onboarding platforms.
How To
For an up-to-date documentation, please refer to our documentation.
Cross-Origin Isolation
WebContainer requiresSharedArrayBuffer to function. In turn, this requires your website to be cross-origin isolated. Among other things, the root document must be served with:
Cross-Origin-Embedder-Policy: require-corp
Cross-Origin-Opener-Policy: same-origin

You can check our article on the subject and our docs on browser support for more details.
Serve over HTTPS
Please note that your deployed page must be served over HTTPS. This is not necessary when developing locally, as localhost is exempt from some browser restrictions, but there is no way around it once you deploy to production.
Demo
Check the WebContainer API demo app.
Here's an example main.ts file:
import{WebContainer}from"@webcontainer/api";constfiles: FileSystemTree={"index.js": {file: {contents: "",},},};letwebcontainer: WebContainer;// add a textarea (the editor) and an iframe (a preview window) to the documentdocument.querySelector("#app").innerHTML=` <div class="container"> <div class="editor"> <textarea>I am a textarea</textarea> </div> <div class="preview"> <iframe></iframe> </div> </div>`;// the editorconsttextarea=document.querySelector("textarea");// the preview windowconstiframe=document.querySelector("iframe");window.addEventListener("load",async()=>{textarea.value=files["index.js"].file.contents;textarea.addEventListener("input",(event)=>{constcontent=event.currentTarget.value;webcontainer.fs.writeFile("/index.js",content);});// call only oncewebcontainer=awaitWebContainer.boot();awaitwebcontainer.mount(files);constexitCode=awaitinstallDependencies();if(exitCode!==0){thrownewError("Installation failed");}startDevServer();});asyncfunctioninstallDependencies(){// install dependenciesconstinstallProcess=awaitwebcontainer.spawn("npm",["install"]);installProcess.output.pipeTo(newWritableStream({write(data){console.log(data);},}));// wait for install command to exitreturninstallProcess.exit;}asyncfunctionstartDevServer(){// run `npm run start` to start the express appawaitwebcontainer.spawn("npm",["run","start"]);// wait for `server-ready` eventwebcontainer.on("server-ready",(port,url)=>{iframe.src=url;});}
Troubleshooting
Cookie blockers, either from third-party addons or built-in into the browser, can prevent WebContainer from running correctly. Check the on('error') event and our docs.
To troubleshoot other problems, check the Troubleshooting page in our docs.
License
Copyright 2023 StackBlitz, Inc.
About
No description, website, or topics provided.
Resources
Readme
Activity
Custom properties
Stars
115 stars
Watchers
10 watching
Forks
94 forks
Report repository
Releases
Packages
Used by
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
WebContainer API Starter
WebContainer API is a browser-based runtime for executing Node.js applications and operating system commands. It enables you to build applications that previously required a server running.
WebContainer API is perfect for building interactive coding experiences. Among its most common use cases are production-grade IDEs, programming tutorials, or employee onboarding platforms.
How To
For an up-to-date documentation, please refer to our documentation.
Cross-Origin Isolation
WebContainer requiresSharedArrayBuffer to function. In turn, this requires your website to be cross-origin isolated. Among other things, the root document must be served with:
Cross-Origin-Embedder-Policy: require-corp
Cross-Origin-Opener-Policy: same-origin

You can check our article on the subject and our docs on browser support for more details.
Serve over HTTPS
Please note that your deployed page must be served over HTTPS. This is not necessary when developing locally, as localhost is exempt from some browser restrictions, but there is no way around it once you deploy to production.
Demo
Check the WebContainer API demo app.
Here's an example main.ts file:
import{WebContainer}from"@webcontainer/api";constfiles: FileSystemTree={"index.js": {file: {contents: "",},},};letwebcontainer: WebContainer;// add a textarea (the editor) and an iframe (a preview window) to the documentdocument.querySelector("#app").innerHTML=` <div class="container"> <div class="editor"> <textarea>I am a textarea</textarea> </div> <div class="preview"> <iframe></iframe> </div> </div>`;// the editorconsttextarea=document.querySelector("textarea");// the preview windowconstiframe=document.querySelector("iframe");window.addEventListener("load",async()=>{textarea.value=files["index.js"].file.contents;textarea.addEventListener("input",(event)=>{constcontent=event.currentTarget.value;webcontainer.fs.writeFile("/index.js",content);});// call only oncewebcontainer=awaitWebContainer.boot();awaitwebcontainer.mount(files);constexitCode=awaitinstallDependencies();if(exitCode!==0){thrownewError("Installation failed");}startDevServer();});asyncfunctioninstallDependencies(){// install dependenciesconstinstallProcess=awaitwebcontainer.spawn("npm",["install"]);installProcess.output.pipeTo(newWritableStream({write(data){console.log(data);},}));// wait for install command to exitreturninstallProcess.exit;}asyncfunctionstartDevServer(){// run `npm run start` to start the express appawaitwebcontainer.spawn("npm",["run","start"]);// wait for `server-ready` eventwebcontainer.on("server-ready",(port,url)=>{iframe.src=url;});}
Troubleshooting
Cookie blockers, either from third-party addons or built-in into the browser, can prevent WebContainer from running correctly. Check the on('error') event and our docs.
To troubleshoot other problems, check the Troubleshooting page in our docs.
License
Copyright 2023 StackBlitz, Inc.
About
No description, website, or topics provided.
Resources
Readme
Activity
Custom properties
Stars
115 stars
Watchers
10 watching
Forks
94 forks
Report repository
Releases
Packages
Used by
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
BranchesTags
Repository files navigation
WebContainer API Starter
WebContainer API is a browser-based runtime for executing Node.js applications and operating system commands. It enables you to build applications that previously required a server running.
WebContainer API is perfect for building interactive coding experiences. Among its most common use cases are production-grade IDEs, programming tutorials, or employee onboarding platforms.
How To
For an up-to-date documentation, please refer to our documentation.
Cross-Origin Isolation
WebContainer requiresSharedArrayBuffer to function. In turn, this requires your website to be cross-origin isolated. Among other things, the root document must be served with:
Cross-Origin-Embedder-Policy: require-corp
Cross-Origin-Opener-Policy: same-origin

You can check our article on the subject and our docs on browser support for more details.
Serve over HTTPS
Please note that your deployed page must be served over HTTPS. This is not necessary when developing locally, as localhost is exempt from some browser restrictions, but there is no way around it once you deploy to production.
Demo
Check the WebContainer API demo app.
Here's an example main.ts file:
import{WebContainer}from"@webcontainer/api";constfiles: FileSystemTree={"index.js": {file: {contents: "",},},};letwebcontainer: WebContainer;// add a textarea (the editor) and an iframe (a preview window) to the documentdocument.querySelector("#app").innerHTML=` <div class="container"> <div class="editor"> <textarea>I am a textarea</textarea> </div> <div class="preview"> <iframe></iframe> </div> </div>`;// the editorconsttextarea=document.querySelector("textarea");// the preview windowconstiframe=document.querySelector("iframe");window.addEventListener("load",async()=>{textarea.value=files["index.js"].file.contents;textarea.addEventListener("input",(event)=>{constcontent=event.currentTarget.value;webcontainer.fs.writeFile("/index.js",content);});// call only oncewebcontainer=awaitWebContainer.boot();awaitwebcontainer.mount(files);constexitCode=awaitinstallDependencies();if(exitCode!==0){thrownewError("Installation failed");}startDevServer();});asyncfunctioninstallDependencies(){// install dependenciesconstinstallProcess=awaitwebcontainer.spawn("npm",["install"]);installProcess.output.pipeTo(newWritableStream({write(data){console.log(data);},}));// wait for install command to exitreturninstallProcess.exit;}asyncfunctionstartDevServer(){// run `npm run start` to start the express appawaitwebcontainer.spawn("npm",["run","start"]);// wait for `server-ready` eventwebcontainer.on("server-ready",(port,url)=>{iframe.src=url;});}
Troubleshooting
Cookie blockers, either from third-party addons or built-in into the browser, can prevent WebContainer from running correctly. Check the on('error') event and our docs.
To troubleshoot other problems, check the Troubleshooting page in our docs.
License
Copyright 2023 StackBlitz, Inc.
About
No description, website, or topics provided.
Resources
Readme
Activity
Custom properties
Stars
115 stars
Watchers
10 watching
Forks
94 forks
Report repository
Releases
Packages
Used by
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
WebContainer API Starter
WebContainer API is a browser-based runtime for executing Node.js applications and operating system commands. It enables you to build applications that previously required a server running.
WebContainer API is perfect for building interactive coding experiences. Among its most common use cases are production-grade IDEs, programming tutorials, or employee onboarding platforms.
How To
For an up-to-date documentation, please refer to our documentation.
Cross-Origin Isolation
WebContainer requiresSharedArrayBuffer to function. In turn, this requires your website to be cross-origin isolated. Among other things, the root document must be served with:
Cross-Origin-Embedder-Policy: require-corp
Cross-Origin-Opener-Policy: same-origin

You can check our article on the subject and our docs on browser support for more details.
Serve over HTTPS
Please note that your deployed page must be served over HTTPS. This is not necessary when developing locally, as localhost is exempt from some browser restrictions, but there is no way around it once you deploy to production.
Demo
Check the WebContainer API demo app.
Here's an example main.ts file:
import{WebContainer}from"@webcontainer/api";constfiles: FileSystemTree={"index.js": {file: {contents: "",},},};letwebcontainer: WebContainer;// add a textarea (the editor) and an iframe (a preview window) to the documentdocument.querySelector("#app").innerHTML=` <div class="container"> <div class="editor"> <textarea>I am a textarea</textarea> </div> <div class="preview"> <iframe></iframe> </div> </div>`;// the editorconsttextarea=document.querySelector("textarea");// the preview windowconstiframe=document.querySelector("iframe");window.addEventListener("load",async()=>{textarea.value=files["index.js"].file.contents;textarea.addEventListener("input",(event)=>{constcontent=event.currentTarget.value;webcontainer.fs.writeFile("/index.js",content);});// call only oncewebcontainer=awaitWebContainer.boot();awaitwebcontainer.mount(files);constexitCode=awaitinstallDependencies();if(exitCode!==0){thrownewError("Installation failed");}startDevServer();});asyncfunctioninstallDependencies(){// install dependenciesconstinstallProcess=awaitwebcontainer.spawn("npm",["install"]);installProcess.output.pipeTo(newWritableStream({write(data){console.log(data);},}));// wait for install command to exitreturninstallProcess.exit;}asyncfunctionstartDevServer(){// run `npm run start` to start the express appawaitwebcontainer.spawn("npm",["run","start"]);// wait for `server-ready` eventwebcontainer.on("server-ready",(port,url)=>{iframe.src=url;});}
Troubleshooting
Cookie blockers, either from third-party addons or built-in into the browser, can prevent WebContainer from running correctly. Check the on('error') event and our docs.
To troubleshoot other problems, check the Troubleshooting page in our docs.
License
Copyright 2023 StackBlitz, Inc.
About
No description, website, or topics provided.
Resources
Readme
Activity
Custom properties
Stars
115 stars
Watchers
10 watching
Forks
94 forks
Report repository
Releases
Packages
Used by
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
WebContainer API Starter
WebContainer API is a browser-based runtime for executing Node.js applications and operating system commands. It enables you to build applications that previously required a server running.
WebContainer API is perfect for building interactive coding experiences. Among its most common use cases are production-grade IDEs, programming tutorials, or employee onboarding platforms.
How To
For an up-to-date documentation, please refer to our documentation.
Cross-Origin Isolation
WebContainer requiresSharedArrayBuffer to function. In turn, this requires your website to be cross-origin isolated. Among other things, the root document must be served with:
Cross-Origin-Embedder-Policy: require-corp
Cross-Origin-Opener-Policy: same-origin

You can check our article on the subject and our docs on browser support for more details.
Serve over HTTPS
Please note that your deployed page must be served over HTTPS. This is not necessary when developing locally, as localhost is exempt from some browser restrictions, but there is no way around it once you deploy to production.
Demo
Check the WebContainer API demo app.
Here's an example main.ts file:
import{WebContainer}from"@webcontainer/api";constfiles: FileSystemTree={"index.js": {file: {contents: "",},},};letwebcontainer: WebContainer;// add a textarea (the editor) and an iframe (a preview window) to the documentdocument.querySelector("#app").innerHTML=` <div class="container"> <div class="editor"> <textarea>I am a textarea</textarea> </div> <div class="preview"> <iframe></iframe> </div> </div>`;// the editorconsttextarea=document.querySelector("textarea");// the preview windowconstiframe=document.querySelector("iframe");window.addEventListener("load",async()=>{textarea.value=files["index.js"].file.contents;textarea.addEventListener("input",(event)=>{constcontent=event.currentTarget.value;webcontainer.fs.writeFile("/index.js",content);});// call only oncewebcontainer=awaitWebContainer.boot();awaitwebcontainer.mount(files);constexitCode=awaitinstallDependencies();if(exitCode!==0){thrownewError("Installation failed");}startDevServer();});asyncfunctioninstallDependencies(){// install dependenciesconstinstallProcess=awaitwebcontainer.spawn("npm",["install"]);installProcess.output.pipeTo(newWritableStream({write(data){console.log(data);},}));// wait for install command to exitreturninstallProcess.exit;}asyncfunctionstartDevServer(){// run `npm run start` to start the express appawaitwebcontainer.spawn("npm",["run","start"]);// wait for `server-ready` eventwebcontainer.on("server-ready",(port,url)=>{iframe.src=url;});}
Troubleshooting
Cookie blockers, either from third-party addons or built-in into the browser, can prevent WebContainer from running correctly. Check the on('error') event and our docs.
To troubleshoot other problems, check the Troubleshooting page in our docs.
License
Copyright 2023 StackBlitz, Inc.
About
No description, website, or topics provided.
Resources
Readme
Activity
Custom properties
Stars
115 stars
Watchers
10 watching
Forks
94 forks
Report repository
Releases
Packages
Used by
Contributors
Languages

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

Skip to content
BranchesTags
Repository files navigation
WebContainer API Starter
WebContainer API is a browser-based runtime for executing Node.js applications and operating system commands. It enables you to build applications that previously required a server running.
WebContainer API is perfect for building interactive coding experiences. Among its most common use cases are production-grade IDEs, programming tutorials, or employee onboarding platforms.
How To
For an up-to-date documentation, please refer to our documentation.
Cross-Origin Isolation
WebContainer requiresSharedArrayBuffer to function. In turn, this requires your website to be cross-origin isolated. Among other things, the root document must be served with:
Cross-Origin-Embedder-Policy: require-corp
Cross-Origin-Opener-Policy: same-origin

You can check our article on the subject and our docs on browser support for more details.
Serve over HTTPS
Please note that your deployed page must be served over HTTPS. This is not necessary when developing locally, as localhost is exempt from some browser restrictions, but there is no way around it once you deploy to production.
Demo
Check the WebContainer API demo app.
Here's an example main.ts file:
import{WebContainer}from"@webcontainer/api";constfiles: FileSystemTree={"index.js": {file: {contents: "",},},};letwebcontainer: WebContainer;// add a textarea (the editor) and an iframe (a preview window) to the documentdocument.querySelector("#app").innerHTML=` <div class="container"> <div class="editor"> <textarea>I am a textarea</textarea> </div> <div class="preview"> <iframe></iframe> </div> </div>`;// the editorconsttextarea=document.querySelector("textarea");// the preview windowconstiframe=document.querySelector("iframe");window.addEventListener("load",async()=>{textarea.value=files["index.js"].file.contents;textarea.addEventListener("input",(event)=>{constcontent=event.currentTarget.value;webcontainer.fs.writeFile("/index.js",content);});// call only oncewebcontainer=awaitWebContainer.boot();awaitwebcontainer.mount(files);constexitCode=awaitinstallDependencies();if(exitCode!==0){thrownewError("Installation failed");}startDevServer();});asyncfunctioninstallDependencies(){// install dependenciesconstinstallProcess=awaitwebcontainer.spawn("npm",["install"]);installProcess.output.pipeTo(newWritableStream({write(data){console.log(data);},}));// wait for install command to exitreturninstallProcess.exit;}asyncfunctionstartDevServer(){// run `npm run start` to start the express appawaitwebcontainer.spawn("npm",["run","start"]);// wait for `server-ready` eventwebcontainer.on("server-ready",(port,url)=>{iframe.src=url;});}
Troubleshooting
Cookie blockers, either from third-party addons or built-in into the browser, can prevent WebContainer from running correctly. Check the on('error') event and our docs.
To troubleshoot other problems, check the Troubleshooting page in our docs.
License
Copyright 2023 StackBlitz, Inc.
About
No description, website, or topics provided.
Resources
Readme
Activity
Custom properties
Stars
115 stars
Watchers
10 watching
Forks
94 forks
Report repository
Releases
Packages
Used by
Contributors
Languages