A client-library update or API-version change can affect more than compilation. Field names, optional values, error categories, pagination, and authentication behavior all belong in the review.
Start with the provider's current change notes and contract. Do not infer compatibility from a version number alone.
Make a focused comparison
List the endpoints your product actually uses. Compare required request fields, response shapes, status handling, token behavior, and cursor rules for those endpoints. Mark any changed assumptions in your boundary adapter and fixtures.
Keep optional catalog data optional unless the new contract says otherwise. A migration that starts requiring artwork or a publication date can break ordinary records that were previously valid.
For listener operations, test a complete account journey: sign in through your application, obtain the correct credential, read state, make one controlled change, and sign out. Check ownership and error paths as well as the happy path.
Prepare a release decision
Run the new client against a controlled environment before production. Use a small live smoke test where authorized. Review the old and new results side by side rather than accepting a freshly generated fixture because it came from the new code.
Choose a rollback plan that accounts for data changes. Reverting code may not safely undo a write format or migration that has already affected stored records.
After release, watch authentication errors, validation failures, and request volume. A compatible API response can still expose an application bug that increases repeated fetching.
Keep the review notes short and specific. They should explain which integration assumptions changed and what evidence supports the new behavior.