Do I need to refetch the item accounts manually after a connection is updated through the update flow?
The Plaid docs mention:
When an Item is restored from the ITEM_LOGIN_REQUIRED state via update mode, if it has been initialized with a product that sends Item webhooks (such as Transactions or Investments), the next webhook fired for the Item will include data for all missed information back to the last time Plaid made a successful connection to the Item.
Do I need to manually, if the upgrade was successful, receive the onSuccess() callback and then call the plaid /accounts/get endpoint here to refetch all the accounts that are out-of-date (in my db) or will there be a webhook code fired to notify me that the accounts need to be refetched?
I mostly want to update the account balances in my db.
This question is really more broadly about account balance updating in Plaid, not so much about update mode itself.
When background balance updates occur is going to depend on which Plaid products you are using. There is no single, Plaid-wide webhook that fires when account balances are updated.
Products that trigger regular balance updates (like, as mentioned in the example, Transactions and Investments) have their own specific webhooks. If you get an update webhook from those products, it means that the balance provided by /accounts/get was also updated. But if you aren't using one of those products, you probably aren't going to be receiving regular, automatic balance updates, update mode or no.* You can still trigger an active balance update at any time by using the paid endpoint /accounts/balance/get.
*I think that, technically, Signal also triggers these updates, although there is no Signal-specific webhook for this.