The datastore nodejs docs mention that the client library will do automatic pagination by default:
By default, google-cloud-node will automatically paginate through all of the results that match a query. However, this sample implements manual pagination using limits and cursor tokens.
What is an example of automatic pagination?
Automatic Pagination, in this context, really means that the API would retrieve all results that match your query. By setting a limit and start cursor you limit the number of rows returned to a specific page. The example sets a limit of 5 rows, and uses a start cursor, so your results never exceed more than 5 entities. If you exclude the limit and start cursor (calls to the respective methods), you would get all the results.