To retrieve issues related to a specific contact using the Redmine API, you can follow these steps. Use the following API endpoint to filter issues by contact_id:
GET /issues.json?set_filter=1&f[]=cf_<contact_field_id>&op[cf_<contact_field_id>]==&v[cf_<contact_field_id>][]=<contact_id>
Replace contact_field_id with the ID of the custom field used to store contact_id in your Redmine setup and contact_id with the specific contact’s ID.
Example Request: If the custom field ID for the contact is 21 and the contact’s ID is 46, the request would look like this:
GET /issues.json?set_filter=1&f[]=cf_21&op[cf_21]==&v[cf_21][]=46
set_filter=1: Enables filtering. f[]: Specifies the filter field (cf_21, the custom field for contact_id). op[cf_21]=: Specifies the operator (in this case, = for equality). v[cf_21][]=46: Specifies the contact ID value to filter by.
Screenshot references:
