Call Other's APIs on User's Behalf

//...
//... existing code
// Get the refresh token from Auth0 session
export const getRefreshToken = async () => {
  const session = await auth0.getSession();
  return session?.tokenSet?.refreshToken;
};

import { initApiPassthrough } from "langgraph-nextjs-api-passthrough";

import { getRefreshToken } from "@/lib/auth0";

export const { GET, POST, PUT, PATCH, DELETE, OPTIONS, runtime } =
  initApiPassthrough({
    apiUrl: process.env.LANGGRAPH_API_URL,
    baseRoute: "chat/",
    bodyParameters: async (req, body) => {
      if (
        req.nextUrl.pathname.endsWith("/runs/stream") &&
        req.method === "POST"
      ) {
        return {
          ...body,
          config: {
            configurable: {
              _credentials: {
                refreshToken: await getRefreshToken(),
              },
            },
          },
        };
      }

      return body;
    },
  });

//...
import { GmailSearch } from "@langchain/community/tools/gmail";
import { getAccessToken, withGoogleConnection } from "./auth0-ai";

//... existing code

// Provide the access token to the Gmail tools
const gmailParams = {
  credentials: {
    accessToken: getAccessToken,
  },
};

const tools = [
  //... existing tools
  withGoogleConnection(new GmailSearch(gmailParams)),
];
//... existing code
export const agent = createReactAgent({
  llm,
  tools: new ToolNode(tools, {
    // Error handler must be disabled in order to trigger interruptions from within tools.
    handleToolErrors: false,
  }),
  // Modify the stock prompt in the prebuilt agent.
  prompt: AGENT_SYSTEM_TEMPLATE,
  store,
  checkpointer,
});

//...
import { FederatedConnectionInterruptHandler } from '@/components/auth0-ai/FederatedConnections/FederatedConnectionInterruptHandler';

//... existing code
export function ChatWindow(props: {
  //... existing code
}) {
  const [threadId, setThreadId] = useQueryState('threadId');
  const [input, setInput] = useState('');
  const chat = useStream({
    apiUrl: props.endpoint,
    assistantId: 'agent',
    threadId,
    onThreadId: setThreadId,
    onError: (e: any) => {
      console.error('Error: ', e);
      toast.error(`Error while processing your request`, { description: e.message });
    },
  });
  //... existing code
  return (
    <StickToBottom>
      <StickyToBottomContent
        className="absolute inset-0"
        contentClassName="py-8 px-2"
        content={
          chat.messages.length === 0 ? (
            <div>{props.emptyStateComponent}</div>
          ) : (
            <>
              <ChatMessages
                aiEmoji={props.emoji}
                messages={chat.messages}
                emptyStateComponent={props.emptyStateComponent}
              />
              <div className="flex flex-col max-w-[768px] mx-auto pb-12 w-full">
                <FederatedConnectionInterruptHandler interrupt={chat.interrupt} onFinish={() => chat.submit(null)} />
              </div>
            </>
          )
        }
        {/* ... existing code */}
      ></StickyToBottomContent>
    </StickToBottom>
  );
}