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:

server.js
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// Using Express
const express = require('express');
const app = express();
app.use(express.json());
const plaid = require('plaid');
const client = new plaid.Client({
  clientID: process.env.PLAID_CLIENT_ID,
  secret: process.env.PLAID_SECRET,
  env: plaid.environments.sandbox,
});
app.post('/create_link_token', async (request, response) => {
  try {
    // Get the client_user_id by searching for the current user
    const user = await User.find(...);
    const clientUserId = user.id;
    // Create the link_token with all of your configurations
    const tokenResponse = await client.createLinkToken({
      user: {
        client_user_id: clientUserId,
      },
      client_name: 'Plaid Test App',
      products: ["auth"],
      country_codes: ['US'],
      language: 'en',
      webhook: 'https://webhook.sample.com',
    });
    response.json(tokenResponse);
  } catch (e) {
    // Display error on client
    return response.send({ error: e.message });
  }
});

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.

 
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// 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.