[Skip to content](#main-content) [![Jx Suite](/favicon.svg) Suite](/)Search⌘KESC Jump to [Install Jx Studio](/docs/start/install)[Build your first project](/docs/start/first-project)[Document format](/docs/framework/concepts/documents)[Formula catalog](/docs/framework/reference/formulas) ↵ select↑↓ navigateesc close [Studio](/studio)[Framework](/framework)[Templates](/templates)[Compare](/compare)[Docs](/docs/start/first-project)[GitHub](https://github.com/jxsuite/jx)[Download](/download) ✕ [Studio](/studio)[Framework](/framework)[Templates](/templates)[Compare](/compare)[Docs](/docs/start/first-project)[GitHub](https://github.com/jxsuite/jx) Color scheme [Download](/download) ☰ Docs menu Start here[Overview](/docs/start/)Get started[Install Jx Studio](/docs/start/install/)[Your first project](/docs/start/first-project/)[A tour of Jx Studio](/docs/start/studio-tour/)Tutorials[Tutorial: interactive component](/docs/start/first-component/)[Tutorial: blog with collections](/docs/start/first-collection/)[Video tutorials](/docs/start/videos/)Coming from another tool[Coming from WordPress](/docs/start/coming-from-wordpress/)[Coming from Webflow or Framer](/docs/start/coming-from-webflow/)[Coming from Wix or Squarespace](/docs/start/coming-from-wix/)[Coming from Lovable or Builder.io](/docs/start/coming-from-ai-builders/)Studio[Overview](/docs/studio/)[The desktop app](/docs/studio/desktop/)The workspace[Overview](/docs/studio/interface/)[Welcome screen](/docs/studio/interface/welcome-screen/)[Editors and views](/docs/studio/interface/modes/)[The canvas](/docs/studio/interface/canvas/)[Documents and panes](/docs/studio/interface/tabs/)[Quick Access](/docs/studio/interface/quick-access/)[Keyboard shortcuts](/docs/studio/interface/shortcuts/)[Preferences](/docs/studio/interface/preferences/)[Languages](/docs/studio/interface/languages/)[Problems and progress](/docs/studio/interface/problems-and-progress/)[Commands](/docs/studio/interface/commands/)Projects[Overview](/docs/studio/projects/)[Create a project](/docs/studio/projects/create/)[Pages, layouts, components](/docs/studio/projects/pages-layouts-components/)[The Content workspace](/docs/studio/projects/browse/)[Starter templates](/docs/studio/projects/starters/)[Media](/docs/studio/projects/media/)[Content types](/docs/studio/projects/content-types/)[Project settings](/docs/studio/projects/settings/)[Dependencies and imports](/docs/studio/projects/dependencies/)Edit mode[Overview](/docs/studio/editing/)[Writing and formatting](/docs/studio/editing/writing/)[Slash commands](/docs/studio/editing/slash-commands/)[Frontmatter and metadata](/docs/studio/editing/frontmatter/)[Grid mode](/docs/studio/editing/grid/)Design mode[Overview](/docs/studio/design/)[Outline](/docs/studio/design/layers/)[Insert](/docs/studio/design/elements/)[Content tab](/docs/studio/design/properties/)[Style inspector](/docs/studio/design/style-inspector/)[Breakpoints](/docs/studio/design/breakpoints/)[States and selectors](/docs/studio/design/states-and-selectors/)[Design tokens](/docs/studio/design/tokens/)[Project Styles](/docs/studio/design/stylebook/)[Working with components](/docs/studio/design/components/)[Repeaters](/docs/studio/design/repeaters/)Logic[Overview](/docs/studio/logic/)[Formulas and expressions](/docs/studio/logic/formulas/)[Formula workspace](/docs/studio/logic/formula-workspace/)[Statements](/docs/studio/logic/statements/)[Logic tab](/docs/studio/logic/events/)[Data](/docs/studio/logic/data/)[Data sources](/docs/studio/logic/data-sources/)[Code editing](/docs/studio/logic/code/)Databases[Overview](/docs/studio/data/)[Connections](/docs/studio/data/connections/)[Data tables](/docs/studio/data/tables/)[Data grid](/docs/studio/data/grid/)[Auth and secrets](/docs/studio/data/auth-and-secrets/)AI assistant[Overview](/docs/studio/ai/)[The AI assistant](/docs/studio/ai/chat/)[Document assistant](/docs/studio/ai/document-assistant/)Publish[Overview](/docs/studio/publish/)[Source control](/docs/studio/publish/source-control/)[GitHub](/docs/studio/publish/github/)[Cloudflare Pages](/docs/studio/publish/cloudflare/)[Other hosts](/docs/studio/publish/other-hosts/)[Redirects](/docs/studio/publish/redirects/)[Real-time collaboration](/docs/studio/publish/collaboration/)Framework[Overview](/docs/framework/)Concepts[Documents](/docs/framework/concepts/documents/)[Elements](/docs/framework/concepts/elements/)[Components](/docs/framework/concepts/components/)[Props and scope](/docs/framework/concepts/props-and-scope/)[State](/docs/framework/concepts/state/)[Reactivity](/docs/framework/concepts/reactivity/)[References](/docs/framework/concepts/references/)[Expressions](/docs/framework/concepts/expressions/)[Statements](/docs/framework/concepts/statements/)[Functions and sidecars](/docs/framework/concepts/functions/)[Styling](/docs/framework/concepts/styling/)[Color schemes](/docs/framework/concepts/color-schemes/)[Popovers and overlays](/docs/framework/concepts/overlays/)[Accessibility](/docs/framework/concepts/accessibility/)[Lists and iteration](/docs/framework/concepts/lists/)[Data prototypes](/docs/framework/concepts/data-prototypes/)[Timing](/docs/framework/concepts/timing/)[Dynamic switching](/docs/framework/concepts/switching/)[Security](/docs/framework/concepts/security/)Site architecture[Overview](/docs/framework/site/)[project.json](/docs/framework/site/project-json/)[Routing](/docs/framework/site/routing/)[Layouts](/docs/framework/site/layouts/)[Content collections](/docs/framework/site/content-collections/)[Jx Markdown](/docs/framework/site/jx-markdown/)[Obsidian vault as content](/docs/framework/site/obsidian-vault/)[Relationships](/docs/framework/site/relationships/)[SEO and metadata](/docs/framework/site/seo/)[Locales and languages](/docs/framework/site/i18n/)[Images](/docs/framework/site/images/)[Redirects](/docs/framework/site/redirects/)[Feeds](/docs/framework/site/feeds/)[Site search](/docs/framework/site/search/)[Build output and adapters](/docs/framework/site/deployment/)How compilation works[Overview](/docs/framework/build/)[The dev server](/docs/framework/build/dev-server/)[CLI commands](/docs/framework/build/cli/)Working with agents[Overview](/docs/framework/agents/)[Authoring rules for agents](/docs/framework/agents/authoring-rules/)[Machine-readable docs](/docs/framework/agents/machine-readable/)Reference[Overview](/docs/framework/reference/)[Formula catalog](/docs/framework/reference/formulas/)[Operator reference](/docs/framework/reference/operators/)Extending[Overview](/docs/extending/)Extensions[Extension anatomy](/docs/extending/extensions/anatomy/)[Schema composition](/docs/extending/extensions/schema-composition/)[Custom classes](/docs/extending/extensions/classes/)[Custom formats](/docs/extending/extensions/formats/)[Capability methods](/docs/extending/extensions/capabilities/)[Project sections](/docs/extending/extensions/project-sections/)[Server mounts](/docs/extending/extensions/server/)[Connectors](/docs/extending/extensions/connectors/)[Search indexes](/docs/extending/extensions/search/)[Security and secrets](/docs/extending/extensions/security/)[Tutorial: a TOML format](/docs/extending/extensions/tutorial-toml-format/)[Tutorial: a guestbook](/docs/extending/extensions/tutorial-guestbook/)[First-party extensions](/docs/extending/extensions/first-party/)Embedding[Overview](/docs/extending/embedding/)[Hosting the Studio assets](/docs/extending/embedding/hosting/)[Writing a platform adapter](/docs/extending/embedding/platform-adapter/)[The backend protocol](/docs/extending/embedding/backend-protocol/)[Dev server internals](/docs/extending/embedding/dev-server/)[Embedding the runtime in your app](/docs/extending/embedding/runtime-host/)[Writing assistant tools](/docs/extending/embedding/assistant-harness/)UI kit[The Jx UI kit](/docs/extending/ui-kit/)Reference[Protocol routes](/docs/extending/reference/studio-routes/)[Implementation status](/docs/extending/reference/implementation-status/)[Spec changelog](/docs/extending/reference/spec-changelog/)[Standards alignment](/docs/extending/reference/standards/)Contributing[Working in the monorepo](/docs/extending/contributing/monorepo/)[Contributing to these docs](/docs/extending/contributing/docs/)[AI assistant evals](/docs/extending/contributing/ai-evals/) # Documents > **Studio writes this format for you.** Every page and component you build in Studio is saved as one of these files. Open the [Code editor](/docs/studio/logic/code) to see the raw source of whatever document you have open. A Jx document is a single `.json` file that describes one piece of user interface: its structure, its styling, the state it holds, and the behavior attached to it. The tree of JSON objects mirrors the DOM, the browser's own object model, so property names like `tagName` and `textContent` mean exactly what they mean to a browser. Simple documents are fully self-describing: no template language, no companion script file. The smallest complete document: ```json shiki ``` ## Root fields Every document is a JSON object with up to six top-level fields: | Field | Required | Description | | ---------- | ----------- | --------------------------------------------------------------------------------------------------------------------------------------- | | `$schema` | Recommended | Schema the file is checked against: the dialect URI, or the project's generated bundle (below) | | `$id` | Recommended | Component identifier, used by tooling | | `$defs` | Optional | Pure JSON Schema type definitions, tooling only, never rendered | | `state` | Optional | Reactive state: values, computed entries, functions, and data sources. See [State](/docs/framework/concepts/state) | | `tagName` | Required | HTML tag name for the root element | | `children` | Optional | Array of child [elements](/docs/framework/concepts/elements), text nodes, and [repeaters](/docs/framework/concepts/lists), mixed freely | Only `tagName` is required. A document can also carry `$media` (named breakpoints, see [Styling](/docs/framework/concepts/styling)) and `$elements` (custom-element dependencies, see [Components](/docs/framework/concepts/components)). Note `https://jxsuite.com/schema/v1` names the dialect, which is what you want for a document that travels on its own. Inside a project, point `$schema` at the `document.schema.json` that [`jx schema`](/docs/framework/build/cli) writes into the project root instead. That bundle is the core schema *plus* every enabled extension's contributions, so your editor's autocomplete and `jx validate` are reading the same rules. See [Schema composition](/docs/extending/extensions/schema-composition) . The pointer is resolved relative to the file that carries it, so it needs one `../` per folder level: `"../document.schema.json"` from `pages/index.json` , `"../../document.schema.json"` from `pages/blog/post.json` . Too few and it points at a file that does not exist, which every validator reports as an unresolvable schema rather than as a document error. ## `$defs`, the type definitions `$defs` holds pure JSON Schema 2020-12 type definitions. They exist for tooling (validation, autocomplete, Studio's input controls) and produce nothing at runtime: ```json shiki ``` State entries reference these types with `$ref` (`{ "$ref": "#/$defs/Count" }`). `$defs` entries never contain `default`, `$prototype`, or template strings; runtime values belong in `state`. ## Component or page fragment What a document *is* follows from its root `tagName` and where the file lives: - A root `tagName`**containing a hyphen** (`"my-counter"`, `"user-card"`) defines a **custom element**, a reusable [component](/docs/framework/concepts/components) that other documents instantiate by reference. - A root `tagName` that is a **plain HTML tag** (`"main"`, `"section"`) is a **page fragment**: a tree that renders in place, either as a route in a site's `pages/` directory (see [Routing](/docs/framework/site/routing)) or inlined into another document via `$ref` (see [References](/docs/framework/concepts/references)). Either kind may declare `state`; the difference is that a custom element gets its own isolated scope and a `$props` boundary (see [Props and scope](/docs/framework/concepts/props-and-scope)). ## Why plain JSON Jx documents are valid JSON, rather than JavaScript object literals, JSX, or a template DSL. That distinction is load-bearing: - JSON serializes and deserializes without executing code. - There is no `this` ambiguity; self-references are explicit `$ref` pointers. - Visual builders, IDEs, validators, and bundlers understand it natively. - JSON Schema tooling (validation, autocomplete, LSP) applies directly. The format also follows the **rule of least power**: prefer a `$ref` binding over a template expression, a template expression over a [declarative expression](/docs/framework/concepts/expressions), and a handler [function](/docs/framework/concepts/functions) only when logic cannot be expressed otherwise. ## How it works Jx is a JSON Schema dialect: any 2020-12-compatible validator can check a document against the Jx meta-schema identified by `$schema`. In development, the runtime loads the `.json` file, builds a reactive scope from `state`, and renders the tree with real DOM calls. In production, the [build](/docs/framework/build) compiles the JSON away, emitting plain JavaScript classes, static HTML, and extracted CSS. ## Rules - A document must be valid JSON: no comments, no trailing commas, no inline code (behavior lives in `state` entries as strings or structured data). - `tagName` is the only required root field; `$schema` and `$id` are recommended. - `$defs` is tooling-only: no signals, no functions, no runtime artifacts. - Jx reserves the keywords `$prototype`, `$props`, `$switch`, `$map`, `$src`, `$export`, `timing`, `default`, `body`, `arguments`, and `name` on top of the standard JSON Schema vocabulary. - One document per file; a document nests other documents only by `$ref`, never by pasting their JSON inline. ## Related - [Components](/docs/framework/concepts/components): custom elements and the component model - [Elements](/docs/framework/concepts/elements): the objects inside `children` - [State](/docs/framework/concepts/state): the four shapes of a `state` entry - [Routing](/docs/framework/site/routing): how documents in `pages/` become URLs - [Code editing](/docs/studio/logic/code): the Studio surface for raw document source ✕ Start here[Overview](/docs/start/)Get started[Install Jx Studio](/docs/start/install/)[Your first project](/docs/start/first-project/)[A tour of Jx Studio](/docs/start/studio-tour/)Tutorials[Tutorial: interactive component](/docs/start/first-component/)[Tutorial: blog with collections](/docs/start/first-collection/)[Video tutorials](/docs/start/videos/)Coming from another tool[Coming from WordPress](/docs/start/coming-from-wordpress/)[Coming from Webflow or Framer](/docs/start/coming-from-webflow/)[Coming from Wix or Squarespace](/docs/start/coming-from-wix/)[Coming from Lovable or Builder.io](/docs/start/coming-from-ai-builders/)Studio[Overview](/docs/studio/)[The desktop app](/docs/studio/desktop/)The workspace[Overview](/docs/studio/interface/)[Welcome screen](/docs/studio/interface/welcome-screen/)[Editors and views](/docs/studio/interface/modes/)[The canvas](/docs/studio/interface/canvas/)[Documents and panes](/docs/studio/interface/tabs/)[Quick Access](/docs/studio/interface/quick-access/)[Keyboard shortcuts](/docs/studio/interface/shortcuts/)[Preferences](/docs/studio/interface/preferences/)[Languages](/docs/studio/interface/languages/)[Problems and progress](/docs/studio/interface/problems-and-progress/)[Commands](/docs/studio/interface/commands/)Projects[Overview](/docs/studio/projects/)[Create a project](/docs/studio/projects/create/)[Pages, layouts, components](/docs/studio/projects/pages-layouts-components/)[The Content workspace](/docs/studio/projects/browse/)[Starter templates](/docs/studio/projects/starters/)[Media](/docs/studio/projects/media/)[Content types](/docs/studio/projects/content-types/)[Project settings](/docs/studio/projects/settings/)[Dependencies and imports](/docs/studio/projects/dependencies/)Edit mode[Overview](/docs/studio/editing/)[Writing and formatting](/docs/studio/editing/writing/)[Slash commands](/docs/studio/editing/slash-commands/)[Frontmatter and metadata](/docs/studio/editing/frontmatter/)[Grid mode](/docs/studio/editing/grid/)Design mode[Overview](/docs/studio/design/)[Outline](/docs/studio/design/layers/)[Insert](/docs/studio/design/elements/)[Content tab](/docs/studio/design/properties/)[Style inspector](/docs/studio/design/style-inspector/)[Breakpoints](/docs/studio/design/breakpoints/)[States and selectors](/docs/studio/design/states-and-selectors/)[Design tokens](/docs/studio/design/tokens/)[Project Styles](/docs/studio/design/stylebook/)[Working with components](/docs/studio/design/components/)[Repeaters](/docs/studio/design/repeaters/)Logic[Overview](/docs/studio/logic/)[Formulas and expressions](/docs/studio/logic/formulas/)[Formula workspace](/docs/studio/logic/formula-workspace/)[Statements](/docs/studio/logic/statements/)[Logic tab](/docs/studio/logic/events/)[Data](/docs/studio/logic/data/)[Data sources](/docs/studio/logic/data-sources/)[Code editing](/docs/studio/logic/code/)Databases[Overview](/docs/studio/data/)[Connections](/docs/studio/data/connections/)[Data tables](/docs/studio/data/tables/)[Data grid](/docs/studio/data/grid/)[Auth and secrets](/docs/studio/data/auth-and-secrets/)AI assistant[Overview](/docs/studio/ai/)[The AI assistant](/docs/studio/ai/chat/)[Document assistant](/docs/studio/ai/document-assistant/)Publish[Overview](/docs/studio/publish/)[Source control](/docs/studio/publish/source-control/)[GitHub](/docs/studio/publish/github/)[Cloudflare Pages](/docs/studio/publish/cloudflare/)[Other hosts](/docs/studio/publish/other-hosts/)[Redirects](/docs/studio/publish/redirects/)[Real-time collaboration](/docs/studio/publish/collaboration/)Framework[Overview](/docs/framework/)Concepts[Documents](/docs/framework/concepts/documents/)[Elements](/docs/framework/concepts/elements/)[Components](/docs/framework/concepts/components/)[Props and scope](/docs/framework/concepts/props-and-scope/)[State](/docs/framework/concepts/state/)[Reactivity](/docs/framework/concepts/reactivity/)[References](/docs/framework/concepts/references/)[Expressions](/docs/framework/concepts/expressions/)[Statements](/docs/framework/concepts/statements/)[Functions and sidecars](/docs/framework/concepts/functions/)[Styling](/docs/framework/concepts/styling/)[Color schemes](/docs/framework/concepts/color-schemes/)[Popovers and overlays](/docs/framework/concepts/overlays/)[Accessibility](/docs/framework/concepts/accessibility/)[Lists and iteration](/docs/framework/concepts/lists/)[Data prototypes](/docs/framework/concepts/data-prototypes/)[Timing](/docs/framework/concepts/timing/)[Dynamic switching](/docs/framework/concepts/switching/)[Security](/docs/framework/concepts/security/)Site architecture[Overview](/docs/framework/site/)[project.json](/docs/framework/site/project-json/)[Routing](/docs/framework/site/routing/)[Layouts](/docs/framework/site/layouts/)[Content collections](/docs/framework/site/content-collections/)[Jx Markdown](/docs/framework/site/jx-markdown/)[Obsidian vault as content](/docs/framework/site/obsidian-vault/)[Relationships](/docs/framework/site/relationships/)[SEO and metadata](/docs/framework/site/seo/)[Locales and languages](/docs/framework/site/i18n/)[Images](/docs/framework/site/images/)[Redirects](/docs/framework/site/redirects/)[Feeds](/docs/framework/site/feeds/)[Site search](/docs/framework/site/search/)[Build output and adapters](/docs/framework/site/deployment/)How compilation works[Overview](/docs/framework/build/)[The dev server](/docs/framework/build/dev-server/)[CLI commands](/docs/framework/build/cli/)Working with agents[Overview](/docs/framework/agents/)[Authoring rules for agents](/docs/framework/agents/authoring-rules/)[Machine-readable docs](/docs/framework/agents/machine-readable/)Reference[Overview](/docs/framework/reference/)[Formula catalog](/docs/framework/reference/formulas/)[Operator reference](/docs/framework/reference/operators/)Extending[Overview](/docs/extending/)Extensions[Extension anatomy](/docs/extending/extensions/anatomy/)[Schema composition](/docs/extending/extensions/schema-composition/)[Custom classes](/docs/extending/extensions/classes/)[Custom formats](/docs/extending/extensions/formats/)[Capability methods](/docs/extending/extensions/capabilities/)[Project sections](/docs/extending/extensions/project-sections/)[Server mounts](/docs/extending/extensions/server/)[Connectors](/docs/extending/extensions/connectors/)[Search indexes](/docs/extending/extensions/search/)[Security and secrets](/docs/extending/extensions/security/)[Tutorial: a TOML format](/docs/extending/extensions/tutorial-toml-format/)[Tutorial: a guestbook](/docs/extending/extensions/tutorial-guestbook/)[First-party extensions](/docs/extending/extensions/first-party/)Embedding[Overview](/docs/extending/embedding/)[Hosting the Studio assets](/docs/extending/embedding/hosting/)[Writing a platform adapter](/docs/extending/embedding/platform-adapter/)[The backend protocol](/docs/extending/embedding/backend-protocol/)[Dev server internals](/docs/extending/embedding/dev-server/)[Embedding the runtime in your app](/docs/extending/embedding/runtime-host/)[Writing assistant tools](/docs/extending/embedding/assistant-harness/)UI kit[The Jx UI kit](/docs/extending/ui-kit/)Reference[Protocol routes](/docs/extending/reference/studio-routes/)[Implementation status](/docs/extending/reference/implementation-status/)[Spec changelog](/docs/extending/reference/spec-changelog/)[Standards alignment](/docs/extending/reference/standards/)Contributing[Working in the monorepo](/docs/extending/contributing/monorepo/)[Contributing to these docs](/docs/extending/contributing/docs/)[AI assistant evals](/docs/extending/contributing/ai-evals/) [![Jx Suite](/favicon.svg) Suite](/)The visual IDE for the web. Build any website, save it as plain files, own it forever. MIT licensed. Product [Studio](/studio)[Download](/download)[Templates](/templates)[Features](/features)[Compare](/compare)[Jx Cloud (soon)](/cloud) Developers [Docs](/docs/start/first-project)[Framework](/framework)[Get Studio](/docs/start/install)[Spec](/docs/framework)[GitHub](https://github.com/jxsuite/jx) Project [MIT License](https://github.com/jxsuite/jx/blob/main/LICENSE)[Releases](https://github.com/jxsuite/jx/releases/latest)[Privacy](/privacy)[Terms](/terms)[Support](/support) Built with Jx Suite. © 2026 Avunu LLC. Open source under the MIT License.