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Components / MentionInput

MentionInput

A textarea with an @-mention picker that emits both the text and the ids present in it. Edit a handle away and its id goes with it, so you never notify someone whose name is no longer in the comment. maxMentions caps the blast radius before the notification is sent.

$ npx shadcn@latest add https://input-cn.vercel.app/r/mention-input.json
Build with an agent

Hand this to Claude Code

1,561 chars

Most people reach this component through an agent rather than by reading the page. Pick how you want it wired and take a prompt that already carries the canonical value, the real prop names and the mistakes worth avoiding.

Wiring
Extras
Open in Claude Code

Nothing runs on its own. The link opens the tool with the prompt typed into the box; you read it and press Enter. If the button does nothing, Claude Code is not installed on this machine — use Copy prompt instead.

Live demo

Type @ then a letter. Delete a mention and its id goes with it.

value = "" · ids []

Constraints

Validation rules, declared as props. Each one produces its own message and its own data-rule value, so a test can assert the rule rather than the sentence.

PROPTYPEDESCRIPTION
maxLength?number—
minMentions?number—
maxMentions?numberCaps notification blast radius.

Props

PROPTYPEDESCRIPTION
peoplereadonly Person[]—
limit?numberSuggestions shown at once. Default 8.
label?ReactNodeVisible label. Supply this or `aria-label` — a field with neither has no accessible name.
hint?ReactNodeHelper text under the field. Replaced by the error message while one is showing.
layout?MentionLayout`compact` fits more people on screen; `rich` disambiguates duplicate names.
rows?number—

Shared props

Implemented identically by all eleven components. These tables are generated from the source interfaces at build time, so a renamed prop changes this page rather than quietly making it wrong.

PROPTYPEDESCRIPTION
value?TCanonical value. Controlled mode.
defaultValue?TCanonical value. Uncontrolled mode. Mutually exclusive with `value`.
onChange?(value: T) => voidEmits the canonical value — never a DOM event.
onBlur?() => voidFires when focus leaves the whole component, not between its parts.
name?stringApplied to the hidden canonical input so FormData carries the real value.
disabled?boolean—
readOnly?boolean—
required?boolean | string—
validate?(value: T) => true | stringCustom synchronous rule. Return true, or the message to display.
messages?MessageMapOverride built-in messages by rule name.
showError?ShowErrorDefault `"touched"`.
onValidityChange?(state: ValidityState) => voidReports validity upward regardless of mode.
mode?FieldModeForce a mode instead of auto-detecting. Escape hatch only.
variant?FieldVariantSurface treatment. Default `"outline"`.
size?FieldSizeDensity. Default `"default"` (32px).
id?string—
className?string—
placeholder?string—
autoFocus?boolean—
aria-label?string—
aria-labelledby?string—
aria-describedby?string—
aria-invalid?boolean | "true" | "false"—

With react-hook-form

import { useForm, Controller } from "react-hook-form"
import { zodResolver } from "@hookform/resolvers/zod"
import { mentionSchema } from "@inputcn/mention/schema"
import { MentionInput } from "@/components/ui/mention-input"
import { z } from "zod"

// The companion schema validates the CANONICAL value, so the resolver and the
// field can never disagree about what "valid" means.
const schema = z.object({ comment: mentionSchema() })

export function Example() {
  const { control } = useForm({ resolver: zodResolver(schema) })

  return (
    <Controller
      name="comment"
      control={control}
      render={({ field, fieldState }) => (
        <MentionInput
          label="Comment"
          {...field}
          aria-invalid={fieldState.invalid}
        />
      )}
    />
  )
}

With a Server Action

import { MentionInput } from "@/components/ui/mention-input"

export default function Page() {
  return (
    <form action={save}>
      <MentionInput name="comment" label="Comment" />
      <button>Save</button>
    </form>
  )
}

async function save(data: FormData) {
  "use server"
  // The hidden canonical input carries the real value, not the display text.
  const comment = data.get("comment") // { text, ids }
}

Keyboard

KEYDOES
@Opens the picker — except inside an email address.
Arrow keysMoves through the suggestions.
EnterInserts the highlighted handle and a trailing space.
EscapeCloses the picker and leaves the text alone.

Worth knowing

The textarea is not a combobox. ARIA 1.2 permits that role on an <input>, not on a multi-line control, so the suggestion count is announced through a polite live region instead.

Emits MentionValue, for example { text, ids }. Keyboard operation is covered by automated tests; screen readers have not been verified yet.

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