Handling an invalid Link Token

Catch the error in the onExit callback and refetch a new link_token for the next time the user opens Link

Occasionally, the end user may invalidate the existing link_token that was used to open Link by taking too long to go through the flow (30+ minutes), or attempting too many invalid logins. If this happens, Link will exit with an INVALID_LINK_TOKEN error code.

To allow your user to open Link again, recognize the error in the onExit callback, fetch a new link_token, and use it to reinitialize Link. You can obtain a new link_token by making another /link/token/create request:

app.post('/api/create_link_token', async function (request, response) {
  // Get the client_user_id by searching for the current user
  const user = await User.find(...);
  const clientUserId = user.id;
  const request = {
    user: {
      // This should correspond to a unique id for the current user.
      client_user_id: clientUserId,
    },
    client_name: 'Plaid Test App',
    products: ['auth'],
    language: 'en',
    webhook: 'https://webhook.example.com',
    redirect_uri: 'https://domainname.com/oauth-page.html',
    country_codes: ['US'],
  };
  try {
    const createTokenResponse = await client.linkTokenCreate(request);
    response.json(createTokenResponse.data);
  } catch (error) {
    // handle error
  }
});

For the Link web integration, reinitializing Link means creating a new iframe. To avoid stacking iframes for each Link initialization, you can clean up the old iframe by calling the destroy() method on the Plaid Link handler.

// Initialize Link with a new link_token each time.
const configs = {
  token: (await $.post('/create_link_token')).link_token,
  onSuccess: (public_token, metadata) => {
    // Send the public_token to your app server.
  },
  onExit: (err, metadata) => {
    // The user exited the Link flow with an INVALID_LINK_TOKEN error.
    // This can happen if the token expires or the user has attempted
    // too many invalid logins.
    if (err != null && err.error_code === 'INVALID_LINK_TOKEN') {
      linkHandler.destroy();
      linkHandler = Plaid.create({
        ...configs,
        // Fetch a new link_token because the old one was invalidated.
        token: (await $.post('/create_link_token')).link_token,
      });
    }
    // metadata contains the most recent API request ID and the
    // Link session ID. Storing this information is helpful
    // for support.
  },
};

let linkHandler = Plaid.create(configs);

When the user is ready, they will be able to reopen Link and go through the authentication process again.