Response field custom_key removed

What changed

Reads of this field return undefined, and the failure surfaces wherever that value is used rather than at the call.

Affects tls-certificates-and-hostnames_ssl reachable from 5 operations.

Who is affected

Code that reads Cloudflare's tls-certificates-and-hostnames_ssl objects, used by 5 Cloudflare operations.

Before and after

Code that breaks

// response.custom_key is now undefined
const custom_key = response.custom_key;

Based on Cloudflare’s published API specification. How severity is decided.