Cloud Functions

Call a function by name

firekitCallable wraps a Cloud Function in a typed, reactive caller. Pass the function name as registered in Firebase.

import { firekitCallable } from 'svelte-firekit';

// Type parameters: <InputType, OutputType>
const sendWelcome = firekitCallable<{ userId: string }, { sent: boolean }>('sendWelcomeEmail');

// Call the function
const result = await sendWelcome.call({ userId: 'abc123' });
console.log(result.sent); // true

Instance properties

Property	Type	Description
loading	boolean	true while the call is in flight
error	Error | null	Set if the function call fails
result	OutputType | null	The resolved return value of the last call

Using in a component

<script lang="ts">
  import { firekitCallable } from 'svelte-firekit';

  const invite = firekitCallable<{ email: string }, { success: boolean }>('inviteUser');

  let email = $state('');

  async function handleInvite() {
    await invite.call({ email });
  }
</script>

<input bind:value={email} type="email" placeholder="[email protected]" />

<button onclick={handleInvite} disabled={invite.loading}>
  {invite.loading ? 'Sending…' : 'Send Invite'}
</button>

{#if invite.error}
  <p class="error">{invite.error.message}</p>
{/if}

{#if invite.result?.success}
  <p>Invite sent!</p>
{/if}

Call a function by URL

Use firekitCallableFromURL when you need to call a function at a specific endpoint (e.g. a different region, or a non-default Firebase project).

import { firekitCallableFromURL } from 'svelte-firekit';

const fn = firekitCallableFromURL<{ message: string }, { reply: string }>(
  'https://us-east1-my-project.cloudfunctions.net/myFunction'
);

const result = await fn.call({ message: 'hello' });

firekitCallableFromURL exposes the same loading, error, and result properties as firekitCallable.

Error handling

Firebase Functions errors include a code and details field. Cast to FunctionsError for typed access:

import type { FunctionsError } from 'firebase/functions';

try {
  await myFn.call(input);
} catch (err) {
  const fnErr = err as FunctionsError;
  console.log(fnErr.code);    // e.g. 'functions/permission-denied'
  console.log(fnErr.details); // custom error payload from the function
}