It would be extremely useful to be able to inspect and manage custom fields via the API. This would include (but not necessarily be limited to) things such as:
Retrieving/listing custom fields for a given module with information such as the field name, possible values for select/multiselect fields, etc.
Updating custom fields: adding/changing/removing allowed values for multiselect fields.
The use case for this has popped up quite a few times. Currently we have various select/multiselect fields on deals and contacts which we use for filtering in the search. These fields are also frequently updated with values from the backend, however the possible values can change semi-frequently, which requires a lot of overhead of maintaining the field’s configurations, and also tracking separately the possible values from the backend to make sure they are synchronized and that our updates don’t fail due to sending bad values.Something to note: For some cases we considered changing certain fields to text so that we can allow arbitrary values, however this greatly limits the usefulness of the given field in the search view, and this is not something we could compromise on in certain cases.