--- title: Flake schemas: making flake outputs extensible | daily.dev description: Flake schemas are a proposed extension mechanism for Nix flakes that allows flakes to declare their own output types in a discoverable, tool-friendly way.... canonical: https://daily.dev/posts/flake-schemas-making-flake-outputs-extensible-1vagmpfep twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Flake schemas: making flake outputs extensible | daily.dev og:description: Flake schemas are a proposed extension mechanism for Nix flakes that allows flakes to declare their own output types in a discoverable, tool-friendly way.... og:url: https://daily.dev/posts/flake-schemas-making-flake-outputs-extensible-1vagmpfep og:image: https://api.daily.dev/og/posts/1vAGmpfEp.png og:image:alt: Flake schemas: making flake outputs extensible 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. # Flake schemas: making flake outputs extensible **[Determinate Systems](https://daily.dev/sources/determinate-systems)** · 4 min read · 0 upvotes · 0 comments ## Summary Flake schemas are a proposed extension mechanism for Nix flakes that allows flakes to declare their own output types in a discoverable, tool-friendly way. Currently, tools like `nix flake show` and `nix flake check` only understand a fixed set of built-in output types, leaving custom outputs opaque. With flake schemas, a flake defines a `schemas` output containing functions that enumerate and validate its outputs. This enables tools like the Nix CLI and FlakeHub to display and check any output type generically, without a central registry. A pull request has been submitted to the Nix project to add schema support, and future work includes making flake outputs configurable via the CLI. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#nixos](https://daily.dev/tags/nixos) [View this post on daily.dev](https://daily.dev/posts/flake-schemas-making-flake-outputs-extensible-1vagmpfep) ```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":"Flake schemas: making flake outputs extensible","url":"https://daily.dev/posts/flake-schemas-making-flake-outputs-extensible-1vagmpfep","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/flake-schemas-making-flake-outputs-extensible-1vagmpfep"},"datePublished":"2026-07-26T07:48:25.753Z","dateModified":"2026-07-26T07:50:24.677Z","description":"Flake schemas are a proposed extension mechanism for Nix flakes that allows flakes to declare their own output types in a discoverable, tool-friendly way....","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/3c1225b91b553781eff09d7d50a2fd3e?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/3c1225b91b553781eff09d7d50a2fd3e?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Determinate Systems","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":"Determinate Systems","logo":"https://media.daily.dev/image/upload/s--E2qrkc9w--/c_limit,w_256/f_auto,q_auto/v1785052094/logos/determinate-systems?_a=BAMAMicg0","url":"https://daily.dev/sources/determinate-systems"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/flake-schemas-making-flake-outputs-extensible-1vagmpfep","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"nixos","timeRequired":"PT4M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Determinate Systems","item":"https://daily.dev/sources/determinate-systems"},{"@type":"ListItem","position":3,"name":"Flake schemas: making flake outputs extensible"}]} ```