If you’re using the Update Contact API endpoint, the value passed in the links array is what you’re setting that Contact’s Links to.

So, if you pass an empty links array - you’ll clear their list of links;

PATCH /contacts/crd_12345

{
  "links":  ]
}

But if I give it an updated list of links, it will not delete the ones not present in the new list, right?

The 'links' for a contact are always completely overwritten when you update them. The update doesn't add to the existing links; it replaces them.

For example, if your contact had links: [“123”], then:

• Updating with o] (empty) results in no links.
• Updating with o"456"] results in only link o"456"].
• To add 456 and keep 123, you must update with o"123", "456"].