Migration Guide Template for Product Teams

Track migration completion through your API logs. Monitor the ratio of v1 to v2 API calls over time. When v1 traffic drops to zero (or close to it), migration is complete. For large customers, proactive outreach from your CS team is more reliable than waiting for them to self-migrate.

Offer a time-boxed extension (2-4 weeks, not indefinite). Assign a support engineer to their case. If they are on an enterprise plan, involve their account manager. Document the extension in writing so both sides have a clear record.

Auto-migration is preferable when possible, but only if it can be done without data loss and without breaking existing integrations. For schema changes that alter behavior (not just field names), manual migration is safer because it requires the customer to validate their specific use case. Offer a self-service migration tool as a middle ground.

2-4 weeks after the published deadline as a grace period. Monitor v1 traffic during this window. Contact any remaining v1 users directly. After the grace period, return 410 Gone responses with a link to this migration guide.

Standalone. The deprecation notice is a communication document (what, why, when). The migration guide is a technical document (how). Link between them but keep them separate. Developers will bookmark the migration guide and refer to it repeatedly. They will read the deprecation notice once. ---