--- title: Datasette Apps: Host custom HTML applications inside... description: Simon Willison announces datasette-apps, a new Datasette plugin that lets users host self-contained HTML+JavaScript applications inside Datasette via tightly... canonical: https://daily.dev/posts/datasette-apps-host-custom-html-applications-inside-datasette-brgstofsz twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Datasette Apps: Host custom HTML applications inside Datasette | daily.dev og:description: Simon Willison announces datasette-apps, a new Datasette plugin that lets users host self-contained HTML+JavaScript applications inside Datasette via tightly... og:url: https://daily.dev/posts/datasette-apps-host-custom-html-applications-inside-datasette-brgstofsz og:image: https://api.daily.dev/og/posts/brgStofSZ.png og:image:alt: Datasette Apps: Host custom HTML applications inside Datasette og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Datasette Apps: Host custom HTML applications inside Datasette **[Simon Willison](https://daily.dev/sources/simonwillison)** · 9 min read · 0 upvotes · 0 comments ## Summary Simon Willison announces datasette-apps, a new Datasette plugin that lets users host self-contained HTML+JavaScript applications inside Datasette via tightly sandboxed iframes. Apps can run read-only SQL queries against Datasette databases and optionally perform write operations through pre-defined stored queries. Security is enforced via iframe sandbox attributes combined with injected Content Security Policy headers, preventing cookie access, localStorage access, and external HTTP requests. The plugin supports LLM-assisted app creation through a copyable prompt that includes database schema context. A notable security vulnerability discovered during development—where a low-privilege user could exfiltrate data from admin sessions via CSP allow-listing—was caught by Claude Fable 5 and fixed with a new permission model. The project evolved from an attempt to build a Claude Artifacts-like mechanism for Datasette Agent into a standalone feature enabling rich, interactive data applications. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Datasette Agent](https://daily.dev/posts/datasette-agent-jkkzcqsbj) · Simon Willison · 0 upvotes · 0 comments - [Ship internal applications from your AI Agent with Datadog Apps](https://daily.dev/posts/ship-internal-applications-from-your-ai-agent-with-datadog-apps-kkslnlam2) · Datadog · 1 upvotes · 0 comments - [Fueling visual insights with MCP applications for complex data analysis](https://daily.dev/posts/fueling-visual-insights-with-mcp-applications-for-complex-data-analysis-dnbfvlzyv) · Dynatrace · 1 upvotes · 0 comments - [Claude can write complete Datasette plugins now](https://daily.dev/posts/claude-can-write-complete-datasette-plugins-now-8webhykse) · Simon Willison · 4 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security), [#javascript](https://daily.dev/tags/javascript), [#datasette](https://daily.dev/tags/datasette) [View this post on daily.dev](https://daily.dev/posts/datasette-apps-host-custom-html-applications-inside-datasette-brgstofsz) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Datasette Apps: Host custom HTML applications inside Datasette","url":"https://daily.dev/posts/datasette-apps-host-custom-html-applications-inside-datasette-brgstofsz","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/datasette-apps-host-custom-html-applications-inside-datasette-brgstofsz"},"datePublished":"2026-06-19T00:06:53.229Z","dateModified":"2026-06-19T00:07:16.210Z","description":"Simon Willison announces datasette-apps, a new Datasette plugin that lets users host self-contained HTML+JavaScript applications inside Datasette via tightly...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/aee3762e292f67d9340aec1566989aa8?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/aee3762e292f67d9340aec1566989aa8?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Simon Willison","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Simon Willison","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/cf12b897300740218b35f49a6309ec5b","url":"https://daily.dev/sources/simonwillison"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/datasette-apps-host-custom-html-applications-inside-datasette-brgstofsz","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"security,javascript,datasette","timeRequired":"PT9M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Simon Willison","item":"https://daily.dev/sources/simonwillison"},{"@type":"ListItem","position":3,"name":"Datasette Apps: Host custom HTML applications inside Datasette"}]} ```