---
updatedAt: 2025-07-21T18:54:21.000Z
agentTools:
  projectIndex: https://docs.crezco.com/llms.txt
---

# Versioning

Learn about API versions and specifying a specific version

# Current version

The current version of the Crezco API is `2025-01-31`

# How to specify a specific version

Versioning is handled using the Crezco-Version header. Where the header contains no version information the default version of the API will be used, currently `2025-01-31`. To use a specific version of the API set the header as follows`Crezco-Version: yyyy-MM-dd`, where the value is an ISO 8601 date when the API was released. For example:

`Crezco-Version: 2025-01-31` - use the version of the API released end of January 2025

Backward incompatible changes will result in a new version of the API being released. The version number will correspond to the date of the release.

# Not setting the version in the header

When the header is set to a value that is not supported in the called API you will receive a `406 - Not Acceptable` response. The body will contain a representation of the valid versions that the API supports.