An API response may not contain all the data
An automation exports a list and finishes without errors. The file opens, the columns line up and everything looks right. But that does not prove that every record is there: the process may have read only the first page of the API.
One page is not the whole collection
Many services return data in batches to limit the size of each response. Microsoft Graph, for example, can apply server-side paging without the application asking for it. Its documentation explains that a response includes @odata.nextLink when another page is available.
With this service, follow the complete returned URL until the next-page link is no longer present. Do not extract part of it and rebuild the request: it may contain information needed to continue the same query. Other APIs use cursors or different mechanisms, so read the contract for the specific endpoint.
Define what complete means
Before feeding the result into a report, define the collection you need, including filters and permissions. Reading every page of a query does not grant access to data the account cannot see or fix an incorrect filter.
Record the pages read, the items received and the point at which traversal ended. If the service supplies a total, check what it counts and its scope before comparing it. In Graph, a page can contain zero items, so you still need to interpret the paging state.
Test a case larger than the first page
A small dataset can hide the error during testing. Use authorised test data that exceeds one page and check identifiers from both the start and the end. Include an interruption halfway through: the process should not present a partial result as a finished export.
If a query fails, keep its progress and the reason it stopped without exposing continuation links in public logs. Define how to resume according to the provider’s rules. The aim is not a file that looks complete, but an explanation of why traversal finished and which data it covers.