Json-render ink

Ink terminal renderer for json-render that turns JSON specs into interactive terminal UIs. Use when working with @json-render/ink, building terminal UIs from JSON, creating terminal component catalogs, or rendering AI-generated specs in the terminal.

install

source · Clone the upstream repo

git clone https://github.com/vercel-labs/json-render

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/vercel-labs/json-render "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/ink" ~/.claude/skills/vercel-labs-json-render-ink && rm -rf "$T"

manifest: skills/ink/SKILL.md

source content

@json-render/ink

Ink terminal renderer that converts JSON specs into interactive terminal component trees with standard components, data binding, visibility, actions, and dynamic props.

Quick Start

import { defineCatalog } from "@json-render/core";
import { schema } from "@json-render/ink/schema";
import {
  standardComponentDefinitions,
  standardActionDefinitions,
} from "@json-render/ink/catalog";
import { defineRegistry, Renderer, type Components } from "@json-render/ink";
import { z } from "zod";

// Create catalog with standard + custom components
const catalog = defineCatalog(schema, {
  components: {
    ...standardComponentDefinitions,
    CustomWidget: {
      props: z.object({ title: z.string() }),
      slots: [],
      description: "Custom widget",
    },
  },
  actions: standardActionDefinitions,
});

// Register only custom components (standard ones are built-in)
const { registry } = defineRegistry(catalog, {
  components: {
    CustomWidget: ({ props }) => <Text>{props.title}</Text>,
  } as Components<typeof catalog>,
});

// Render
function App({ spec }) {
  return (
    <JSONUIProvider initialState={{}}>
      <Renderer spec={spec} registry={registry} />
    </JSONUIProvider>
  );
}

Spec Structure (Flat Element Map)

The Ink schema uses a flat element map with a root key:

{
  "root": "main",
  "elements": {
    "main": {
      "type": "Box",
      "props": { "flexDirection": "column", "padding": 1 },
      "children": ["heading", "content"]
    },
    "heading": {
      "type": "Heading",
      "props": { "text": "Dashboard", "level": "h1" },
      "children": []
    },
    "content": {
      "type": "Text",
      "props": { "text": "Hello from the terminal!" },
      "children": []
    }
  }
}

Standard Components

Layout

```
Box
```
- Flexbox layout container (like a terminal
```
<div>
```
). Use for grouping, spacing, borders, alignment. Default flexDirection is row.
```
Text
```
- Text output with optional styling (color, bold, italic, etc.)
```
Newline
```
- Inserts blank lines. Must be inside a Box with flexDirection column.
```
Spacer
```
- Flexible empty space that expands along the main axis.

Content

```
Heading
```
- Section heading (h1: bold+underlined, h2: bold, h3: bold+dimmed, h4: dimmed)
```
Divider
```
- Horizontal separator with optional centered title
```
Badge
```
- Colored inline label (variants: default, info, success, warning, error)
```
Spinner
```
- Animated loading spinner with optional label
```
ProgressBar
```
- Horizontal progress bar (0-1)
```
Sparkline
```
- Inline chart using Unicode block characters
```
BarChart
```
- Horizontal bar chart with labels and values
```
Table
```
- Tabular data with headers and rows
```
List
```
- Bulleted or numbered list
```
ListItem
```
- Structured list row with title, subtitle, leading/trailing text
```
Card
```
- Bordered container with optional title
```
KeyValue
```
- Key-value pair display
```
Link
```
- Clickable URL with optional label
```
StatusLine
```
- Status message with colored icon (info, success, warning, error)
```
Markdown
```
- Renders markdown text with terminal styling

Interactive

```
TextInput
```
- Text input field (events: submit, change)
```
Select
```
- Selection menu with arrow key navigation (events: change)
```
MultiSelect
```
- Multi-selection with space to toggle (events: change, submit)
```
ConfirmInput
```
- Yes/No confirmation prompt (events: confirm, deny)
```
Tabs
```
- Tab bar navigation with left/right arrow keys (events: change)

Visibility Conditions

Use

visible

on elements to show/hide based on state. Syntax:

{ "$state": "/path" }

{ "$state": "/path", "eq": value }

{ "$state": "/path", "not": true }

{ "$and": [cond1, cond2] }

for AND,

{ "$or": [cond1, cond2] }

for OR.

Dynamic Prop Expressions

Any prop value can be a data-driven expression resolved at render time:

{ "$state": "/state/key" }
- reads from state model (one-way read)
{ "$bindState": "/path" }
- two-way binding: use on the natural value prop of form components
{ "$bindItem": "field" }
- two-way binding to a repeat item field

{ "$cond": <condition>, "$then": <value>, "$else": <value> }
- conditional value

{ "$template": "Hello, ${/name}!" }
- interpolates state values into strings

Components do not use a

statePath

prop for two-way binding. Use

{ "$bindState": "/path" }

on the natural value prop instead.

Event System

Components use

emit

to fire named events. The element's

on

field maps events to action bindings:

CustomButton: ({ props, emit }) => (
  <Box>
    <Text>{props.label}</Text>
    {/* emit("press") triggers the action bound in the spec's on.press */}
  </Box>
),

{
  "type": "CustomButton",
  "props": { "label": "Submit" },
  "on": { "press": { "action": "submit" } },
  "children": []
}

Built-in Actions

setState

pushState

, and

removeState

are built-in and handled automatically:

{ "action": "setState", "params": { "statePath": "/activeTab", "value": "home" } }
{ "action": "pushState", "params": { "statePath": "/items", "value": { "text": "New" } } }
{ "action": "removeState", "params": { "statePath": "/items", "index": 0 } }

Repeat (Dynamic Lists)

Use the

repeat

field on a container element to render items from a state array:

{
  "type": "Box",
  "props": { "flexDirection": "column" },
  "repeat": { "statePath": "/items", "key": "id" },
  "children": ["item-row"]
}

Inside repeated children, use

{ "$item": "field" }

to read from the current item and

{ "$index": true }

for the current index.

Streaming

Use

useUIStream

to progressively render specs from JSONL patch streams:

import { useUIStream } from "@json-render/ink";

const { spec, send, isStreaming } = useUIStream({ api: "/api/generate" });

Server-Side Prompt Generation

Use the

./server

export to generate AI system prompts from your catalog:

import { catalog } from "./catalog";

const systemPrompt = catalog.prompt({ system: "You are a terminal assistant." });

Providers

Provider	Purpose
`StateProvider`	Share state across components (JSON Pointer paths). Accepts optional `store` prop for controlled mode.
`ActionProvider`	Handle actions dispatched via the event system
`VisibilityProvider`	Enable conditional rendering based on state
`ValidationProvider`	Form field validation
`FocusProvider`	Manage focus across interactive components
`JSONUIProvider`	Combined provider for all contexts

External Store (Controlled Mode)

Pass a

StateStore

StateProvider

(or

JSONUIProvider

) to use external state management:

import { createStateStore, type StateStore } from "@json-render/ink";

const store = createStateStore({ count: 0 });

<StateProvider store={store}>{children}</StateProvider>

store.set("/count", 1); // React re-renders automatically

When

store

is provided,

initialState

and

onStateChange

are ignored.

createRenderer (Higher-Level API)

import { createRenderer } from "@json-render/ink";
import { standardComponents } from "@json-render/ink";
import { catalog } from "./catalog";

const InkRenderer = createRenderer(catalog, {
  ...standardComponents,
  // custom component overrides here
});

// InkRenderer includes all providers (state, visibility, actions, focus)
render(
  <InkRenderer spec={spec} state={{ activeTab: "overview" }} />
);

Key Exports

Export	Purpose
`defineRegistry`	Create a type-safe component registry from a catalog
`Renderer`	Render a spec using a registry
`createRenderer`	Higher-level: creates a component with built-in providers
`JSONUIProvider`	Combined provider for all contexts
`schema`	Ink flat element map schema (includes built-in state actions)
`standardComponentDefinitions`	Catalog definitions for all standard components
`standardActionDefinitions`	Catalog definitions for standard actions
`standardComponents`	Pre-built component implementations
`useStateStore`	Access state context
`useStateValue`	Get single value from state
`useBoundProp`	Two-way binding for `$bindState` / `$bindItem` expressions
`useActions`	Access actions context
`useAction`	Get a single action dispatch function
`useOptionalValidation`	Non-throwing variant of useValidation
`useUIStream`	Stream specs from an API endpoint
`createStateStore`	Create a framework-agnostic in-memory `StateStore`
`StateStore`	Interface for plugging in external state management
`Components`	Typed component map (catalog-aware)
`Actions`	Typed action map (catalog-aware)
`ComponentContext`	Typed component context (catalog-aware)
`flatToTree`	Convert flat element map to tree structure

Terminal UI Design Guidelines

Use Box for layout (flexDirection, padding, gap). Default flexDirection is row.
Terminal width is ~80-120 columns. Prefer vertical layouts (flexDirection: column) for main structure.
Use borderStyle on Box for visual grouping (single, double, round, bold).
Use named terminal colors: red, green, yellow, blue, magenta, cyan, white, gray.
Use Heading for section titles, Divider to separate sections, Badge for status, KeyValue for labeled data, Card for bordered groups.
Use Tabs for multi-view UIs with visible conditions on child content.
Use Sparkline for inline trends and BarChart for comparing values.