# Versioning

The version is in the address: `https://api.nepzio.com/v1/`.

## Within v1

Changes are **additive only**:

- new endpoints, optional parameters and fields;
- new values in lists of choices;
- new webhook events and error codes.

Nothing your code relies on is removed or renamed, no field changes its type, no always-present field becomes optional, and no endpoint you use gains a required input.

Our build checks every change against the published contract and refuses one that would break an integration.

## A new version

A change that would break integrations waits for `/v2/`. Before then:

- `v2` is announced at least **12 months** before `v1` stops;
- responses from anything going away carry `Deprecation` and `Sunset` headers (RFC 8594);
- everyone with an active key is emailed.

## What's new

Every change is listed in the [changelog](/changelog), also available as an [RSS feed](/changelog.xml).