App Hotkeys and Custom Shortcuts in Lit

App hotkeys are optional. Plain @hotkey and HotkeyController are enough until you need a cheat sheet for your whole app, or a screen where users change hotkeys. They register a hotkey while its element is connected, so a cheat sheet built from live registrations misses hotkeys on routes that have not rendered yet, and a settings screen has nowhere to change them. App hotkeys solve both: you declare every hotkey in one place, publish them with provideAppHotkeys, and attach callbacks where the work happens. Users can then customize any of them, and your app decides how to save their choices.

A declaration holds a hotkey's id, default hotkey, metadata, and options. It never holds a callback. @hotkey and HotkeyController still attach the callbacks.

Declare app hotkeys#

Use defineAppHotkeys in a module that contains only declarations. Keep it free of components and handlers, because it loads with your app shell:

// app-hotkeys.ts
import { defineAppHotkeys } from '@tanstack/lit-hotkeys'

export const appHotkeys = defineAppHotkeys({
  'doc.save': { hotkey: 'Mod+S', meta: { name: 'Save', group: 'Document' } },
  'doc.find': {
    hotkey: 'Mod+F',
    meta: { name: 'Find', group: 'Document' },
    scope: 'editor',
  },
  'nav.home': {
    hotkey: ['G', 'H'],
    meta: { name: 'Go home', group: 'Navigation' },
    options: { timeout: 800 },
  },
  'palette.open': { hotkey: null, meta: { name: 'Command palette' } },
})

declare module '@tanstack/lit-hotkeys' {
  interface Register {
    appHotkeys: typeof appHotkeys
  }
}

• The object key is the app hotkey's id. Treat ids as a stable contract, because saved custom hotkeys use them as keys.
• hotkey is the default: a chord, a sequence, or null for an action without a default. An unbound app hotkey registers nothing until the user assigns one.
• options describe the hotkey itself: capture, conflictBehavior, eventType, ignoreInputs, preventDefault, stopPropagation, plus requireReset for a chord default or timeout for a sequence default. Hotkey options describes each one. Options that don't match the default's kind are type errors. Pass target and enabled where you register the hotkey.
• scope names the scope the hotkey fires in, such as 'editor'. Hotkeys outside the default 'global' scope fire only while their scope is active. Lit has no provider to activate scopes, so activate them on the hotkey manager. See Activate a scope. App hotkeys in different scopes may share a hotkey.

The Register augmentation types AppHotkeysController, the ids it accepts when changing custom hotkeys, and the CustomHotkeys type.

Provide app hotkeys#

Publish the declarations with provideAppHotkeys before your elements render:

// main.ts, before your elements render
import { provideAppHotkeys } from '@tanstack/lit-hotkeys'
import { appHotkeys } from './app-hotkeys'

provideAppHotkeys(appHotkeys)

Lit has no provider component. provideAppHotkeys creates the shared AppHotkeysStore and publishes it for controllers, decorators, and devtools. Call it once at startup; it returns { store, dispose }.

Register app hotkeys#

Pass an app hotkey wherever you pass a hotkey:

import { LitElement } from 'lit'
import { property } from 'lit/decorators.js'
import { HotkeyController, hotkey } from '@tanstack/lit-hotkeys'
import { appHotkeys } from './app-hotkeys'

class Editor extends LitElement {
  @property({ type: Boolean }) dirty = false

  @hotkey(appHotkeys['nav.home'])
  goHome() {}

  constructor() {
    super()
    this.addController(
      new HotkeyController(this, appHotkeys['doc.save'], () => this.save(), () => ({
        enabled: this.dirty,
      })),
    )
  }
}

Controllers and decorators look up the published store, so the registration follows the user's custom hotkey even though you import the declaration directly. Without provideAppHotkeys, the declared default is used.

The registration takes meta and options from the declaration. Options merge in this order: declared options, then call-site options. meta comes only from the declaration, so the cheat sheet and the registration cannot disagree. Call-site options are typed by the declared default's kind, so timeout is accepted for nav.home but not for doc.save.

When the user changes a hotkey, registered app hotkeys move to the new hotkey immediately, even if it changes from a chord to a sequence.

List app hotkeys#

AppHotkeysController.list returns every app hotkey, with its current hotkey and whether anything has registered it. Use it to build a cheat sheet that includes pages that haven't rendered. See List every app hotkey.

Customize and persist hotkeys#

TanStack Hotkeys does not store anything. Pass the user's saved custom hotkeys to provideAppHotkeys and save them when they change:

import { provideAppHotkeys } from '@tanstack/lit-hotkeys'

provideAppHotkeys(appHotkeys, {
  customHotkeys: JSON.parse(localStorage.getItem('hotkeys') ?? '{}'),
  onCustomHotkeysChange: (custom) =>
    localStorage.setItem('hotkeys', JSON.stringify(custom)),
})

• customHotkeys holds only the hotkeys that differ from the declared defaults, keyed by id. null means the user unbound that hotkey. Saving differences means users who never changed a hotkey get new defaults when you change them.
• provideAppHotkeys reads customHotkeys once, and the shared store owns the state afterwards. Saved data can outlive the code that wrote it, so unknown ids and invalid hotkeys are ignored with a warning.
• onCustomHotkeysChange receives the complete custom hotkeys after every change, ready to save. Storage can be anything: local storage, a server, or a user profile.

The hotkey recorder records Mod rather than platform-specific modifiers, so a hotkey saved on one platform works on others.

Change hotkeys#

AppHotkeysController reads and changes the user's custom hotkeys. Pair it with a recorder, so users press the hotkey they want:

import {
  AppHotkeysController,
  HotkeyRecorderController,
  formatForDisplay,
} from '@tanstack/lit-hotkeys'
import type { AppHotkeyId } from '@tanstack/lit-hotkeys'

class ShortcutRow extends LitElement {
  @property() hotkeyId!: AppHotkeyId
  private app = new AppHotkeysController(this)

  private recorder = new HotkeyRecorderController(this, () => ({
    maxSteps: Infinity,
    validate: (hotkey) => {
      const conflicts = this.app.findConflicts(this.hotkeyId, hotkey)
      return conflicts.length === 0 || `Used by ${conflicts[0]?.meta?.name}`
    },
    onRecord: (hotkey) => this.app.setCustomHotkey(this.hotkeyId, hotkey),
    onClear: () => this.app.setCustomHotkey(this.hotkeyId, null),
  }))

  render() {
    const appHotkey = this.app.appHotkeys[this.hotkeyId]
    return html`
      ${appHotkey.meta?.name}:
      ${appHotkey.hotkey ? formatForDisplay(appHotkey.hotkey) : 'Unassigned'}
      <button @click=${() => this.recorder.startRecording()}>Change</button>
      <button @click=${() => this.app.resetCustomHotkey(this.hotkeyId)}>Reset</button>
    `
  }
}

Two app hotkeys conflict when their scopes match or either is in 'global', including app hotkeys with no declared scope, and their hotkeys collide: equal chords, or one sequence starts with the other, including a sequence whose first step equals a chord. Conflicts are checked across every declaration, whether or not it is registered.

Each app hotkey's defaultHotkey holds its declared default, and isCustom in AppHotkeysController.list reports whether the effective hotkey differs from it.

provideAppHotkeys returns the AppHotkeysStore it creates. See the AppHotkeysStore reference to use it directly.