# FilterChip

> Single-select filter toggle chip: a button[aria-pressed] with pill, rectangle, underline, and minimal treatments.

- Status: stable
- Group: form
- Page: https://www.digitaltableteur.com/design-system/components/filter-chip
- Contract: https://www.digitaltableteur.com/contracts/v1/FilterChip.contract.json

## When to use

Use FilterChip inside a labelled single-select filter group when a compact option must expose its active state with aria-pressed. Keep one chip pressed and use count for result totals so the accessible name stays synchronized.

Use FilterChip to filter a visible collection such as a work grid or blog archive.

## When not to use

- Do not use for navigation between panels (that is Tabs).
- Do not nest interactive content inside the label.
- Do not use FilterChip as navigation between content panels; use Tabs.
- Do not use FilterChip for multi-select token input; use MultiCombobox.

## Look-alikes

- MultiCombobox: Do not use FilterChip for multi-select token input; use MultiCombobox.
- Tabs: Do not use FilterChip as navigation between content panels; use Tabs.

## Props

| Prop | Type | Default | Description | Required |
| --- | --- | --- | --- | --- |
| `pressed` | `boolean` | none | Whether this chip's filter is active (rendered as aria-pressed). | Yes |
| `children` | `React.ReactNode` | none | Chip label (compose counts etc. inline). | Yes |
| `variant` | `"underline" \| "minimal" \| "pill" \| "rectangle"` | `pill` | Visual treatment. | No |
| `size` | `"sm" \| "md" \| "lg"` | `md` | Size token. | No |
| `count` | `number` | none | Optional count suffix, rendered as "(n)". | No |
| `className` | `string` | none | Additional CSS class names. | No |

## Variants

- Available variants: `pill`, `rectangle`, `underline`, `minimal` (default `pill`).
- Available sizes: `sm`, `md`, `lg` (default `md`).

## Invalid combinations

The contract records no invalid combinations.

## Keyboard

| Key | Behaviour |
| --- | --- |
| Tab | Moves focus to the control and on to the next focusable element. (standard) |
| Enter | Activates the focused control. (standard) |
| Space | Activates or toggles the focused control. (standard) |

Rows marked (standard) name a key the contract lists without a description; the behaviour shown is the usual one for that key.

## Rules

Every item under When not to use is a MUST NOT. MUST and SHOULD follow RFC 2119.

| Level | Rule | How it is checked |
| --- | --- | --- |
| MUST | ARIA: Aria-pressed reflects the pressed prop (toggle button, not tab) | Not yet verified: no evidence record. WCAG 4.1.2. |
| MUST | ARIA: Parents wrap chips in a labelled role=group. | Not yet verified: no evidence record. WCAG 4.1.2. |
| MUST | Required stories produce no axe violations at the configured severity. | Automated by `npm run test:stories:matrix:ci`. WCAG 2.5.8. |
| MUST | The accessibility tree (role, name, state) matches the committed snapshot for every required story. | Automated by `npm run test:stories:matrix:ci`. WCAG 1.3.1, 4.1.2. |
| MUST | The component remains legible and operable under a real browser forced-colors: active pass. | Automated by `npm run test:stories:hc`. |
| MUST | Every documented keyboard interaction works as specified. | Not yet verified: no evidence record. WCAG 2.1.1, 2.1.2. |
| MUST | A human completed an end-to-end accessibility review of this component. | Manual review, last on 2026-11-04. |
| SHOULD | Keep exactly one chip pressed in a single-select filter group. | Not stated in the contract. |

## Install and import

- Install: `npm install @digitaltableteur/react` (version 0.9.1, restricted access on npm).
- Import: `import { FilterChip } from "@digitaltableteur/react";`
- Entry point: `@digitaltableteur/react/actions` exports it too.
- Styles: import `@digitaltableteur/react/style.css` once at the app boundary.
- Also available as the custom element `<dt-filter-chip>`; see the custom elements manifest.

## Links

- Machine-readable contract (Design System Contract 1.0): https://www.digitaltableteur.com/contracts/v1/FilterChip.contract.json
- Markdown version of this page: https://www.digitaltableteur.com/design-system/components/filter-chip.md
- Component index as JSON: https://www.digitaltableteur.com/design-system/components.json
- All components: https://www.digitaltableteur.com/design-system/components
- Source: The implementation lives in a private repository. This page, its Markdown twin and the contract are generated from it at build time and are the public source of truth.