Large API collections should be read in pages with a durable progress strategy. Data can change during the sync, so a simple page number loop may miss or repeat records depending on the API.
IN THIS ARTICLE
Information to have ready
Identify the provider’s pagination method, stable identifiers and ordering guarantees. Decide whether the sync is a snapshot, incremental update or reconciliation.
01 Choose safe pagination for large API synchronizations
Follow the API’s returned cursor, next link or documented offset method. Do not construct an undocumented page mechanism from assumptions.
Use a suitable page size within the provider’s limits and process records with stable identifiers. Make local updates tolerate repeated records.
Persist progress only after the relevant page work is safely committed. Keep enough state to resume after a process restart without losing the current page.
Handle records added, changed or removed during the run according to the API’s consistency model. Use timestamps or sync tokens only when their semantics are documented.
After the run, reconcile totals or known boundary records where practical and record the time through which the sync is considered complete.
02 Example: resume a paginated catalogue after page two
Imagine an API returns 250 items in pages of 100. Its documented response supplies a next link similar to the header below. Follow the provider’s actual link or cursor format; the demonstration cursor is not a value to send to a live integration.
Link: <https://api.example.com/v1/items?cursor=NEXT_CURSOR>; rel="next"Commit the first 100 local records, then save the next cursor. Repeat for the second page. If the worker stops while saving the final 50, resume from the last committed cursor and upsert records by their stable provider IDs. Validate that returned links remain within the authorised API origin before forwarding credentials.
Expected result: The resumed run finishes with 250 distinct records, not 300 from a duplicated page or 200 from a prematurely advanced checkpoint. A missing next link ends pagination only under the provider’s documented rules.
Confirm the expected result
Test a multi-page collection, a restart midway and a record changed during the run. Confirm the local result neither duplicates stable records nor silently skips a failed page.
Troubleshoot unexpected results
If records disappear between offset pages, inspect changing sort order or deletions. A cursor or provider-supported incremental mechanism may be more appropriate when available.
A common question
Does reaching the final page prove every record is current?
It proves the pagination completed under that API’s behavior. Freshness and consistency still depend on concurrent changes and the sync design.