---
title: Versioning and deprecation | SendHQ Docs
description: Understand major URL versions, compatible additions, deprecation notices, and sunset windows.
canonical: https://sendhq.cc/docs/versioning
last-updated: 2026-09-07
---
# 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.