咨询：能否通过iOS Callkit SDK向SIP URI发起呼叫？

From what I've dug into and tested firsthand, iOS CallKit does not natively support directly dialing SIP URIs.

Here's a clear breakdown of the situation:

• CallKit's core role is to integrate third-party VoIP apps with the system's native call interface—think showing incoming call alerts, syncing with the Phone app's recent calls list, etc. It doesn't come with built-in tools to parse SIP URIs or initiate SIP calls on its own.
• While you can combine CallKit with a dedicated SIP library (like PJSIP or Linphone) to build a full VoIP app that handles SIP calls, there’s no way to trigger a SIP URI dial directly through the CallKit framework itself. Apple hasn’t exposed any public API for this specific use case.
• Your failed attempts make total sense—Apple’s official CallKit documentation never mentions support for SIP URI dialing, and there’s no hidden or standard interface to enable this behavior.

If you need to implement SIP calling on iOS, you’ll have to build out the SIP client logic using a specialized library, then wrap that logic with CallKit to deliver a native call experience. But direct SIP URI dialing via CallKit alone isn’t feasible right now.

内容的提问来源于stack exchange，提问作者Jørgen