/ink

name: ink
description: 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.

@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 "