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Versioning and deprecation
Understand major URL versions, compatible additions, deprecation notices, and sunset windows.
Stable major paths
Customer integrations use a major version in the URL, currently /api/v1. The date-based OpenAPI info.version identifies the exact published contract within that major.
Compatible changes
SendHQ may add optional request fields, response fields, enum values where the schema permits them, and new operations within v1. Clients should ignore unknown response fields and avoid treating an enum as permanently closed unless the schema says so.
Breaking changes
A breaking request, response, authentication, or behavior change requires a new major path such as /api/v2, migration documentation, and an announced transition. The current v1 API is not deprecated.
Deprecation and sunset
When a version is deprecated, SendHQ documents the replacement and migration path and returns Deprecation and Sunset headers where applicable. Deprecated versions remain available for at least 90 days after the published deprecation date unless continued operation creates an urgent security or legal risk.