--- title: "CerteroX API" canonical: "https://ai-docs.certero.com/space/CUP/118654329/CerteroX%20API" format: markdown --- --- With the release of CerteroX v9, the API now supports both **READ** and **WRITE** functionality. The attached guide provides basic instruction on using the API. > ℹ️ **API capabilities by version** > ℹ️ > ℹ️ What the API supports depends on your Certero version. Please check yours before integrating. > ℹ️ > ℹ️ [Certero v9 onwards] **Read & write-back.** Everything in v8, plus write-back for User-Defined Fields (UDFs) and User-Defined Assets (UDAs) **only** — create and update them via the API. > ℹ️ > ℹ️ [Certero v8] **Read-only.** Query and export data only. Nothing can be written back to Certero through the API. --- ## Changelog Updates to the Certero API and this guide. Most recent first. | When | Version | Type | Change | | --- | --- | --- | --- | | June 2026 | Certero v9 | [New] | **Write-back API introduced.** The API can now create and update User-Defined Fields (UDFs) and User-Defined Assets (UDAs) — the only writable items; all other endpoints remain read-only. Part of the Certero v9 release, which also introduces new AI functionality and bug fixes. | | 28th January 2022 | Certero v8 | [New] | Initial release of the read-only API alongside Certero v8. API guide published with authentication and basic usage instructions. |