Client lifecycle

Create one JanuaryClient per signed-in user and share it across screens. Each client has its own native client and token cache and never changes user. On sign-out or an account switch, dispose the client and create a new one. Do the same if the user's timezone changes.

In React

import { useEffect, useState } from 'react';
import { JanuaryClient } from '@januaryai/react-native';
import { tokenProvider } from './januaryTokenProvider';

/** The signed-in user's client; undefined while signed out. */
export function useJanuaryClient(userId: string | undefined) {
  const [client, setClient] = useState<JanuaryClient>();

  useEffect(() => {
    if (!userId) return;
    const next = new JanuaryClient({
      endUserId: userId,
      timezone: Intl.DateTimeFormat().resolvedOptions().timeZone,
      clientTokenProvider: tokenProvider,
    });
    setClient(next);
    return () => {
      setClient(undefined);
      next.dispose();
    };
  }, [userId]);

  return client;
}

Call the hook once, in the component that owns the signed-in session, and pass the client down through a context. It creates a client for each end-user ID and disposes it when the ID changes or the component unmounts.

Don't create the client in useMemo. Strict Mode runs effect cleanups once in development, which would dispose a client the next render still uses. Don't create it at module scope either: the constructor throws when the native module isn't linked (Troubleshooting).

Disposal

dispose() releases the native client and stops its token requests. After that, every call rejects with This JanuaryClient has been disposed.. Calling dispose() again does nothing.