iOS 27 Code Analysis Reveals Siri Can Be Replaced by Third-Party AI Models Like Claude and ChatGPT

Code analyst 'pdfu' analyzed the private frameworks of iOS 27 and macOS Golden Gate, confirming that Apple's new Siri architecture is designed to integrate deeply with third-party AI models.

Model Delegation Mechanism

Through the new Model Delegation mechanism, Claude can appear as a Siri extension just like the existing ChatGPT extension. In macOS's 'Search or Ask' bar, users can directly select AI models via the 'Ask...' context menu.

• Demo 1: Requesting to set a reminder in Apple Reminders via 'Ask Claude' results in Claude interpreting the natural language and Siri creating the actual reminder. If access to system functions is required, Claude hands the task back to Siri.
• Demo 2: In the Siri app chat window, Claude handles a request to generate a CSV file, a task impossible with Siri's native capabilities.

Server-Side Model Replacement Possibility

By configuring the inference provider in Model Manager Services, Apple's server-side Siri models can be completely replaced by other models such as GPT-5.6. In this scenario, ChatGPT receives Apple's Siri planner prompt and tool definitions, handling system action requests, personal data processing, and the generation of Siri interfaces and voice responses.

• Demo 3: It was confirmed that the ChatGPT model searches and summarizes emails on specific topics, sends messages to contacts via the Messages app, and logs the response history on the OpenAI platform web interface.

Regulatory Context and Current Limitations

This discovery aligns with the EU's Digital Markets Act, which requires Apple to provide third-party access to iOS hardware/software features for its own services. The European Commission has argued that this regulation applies to Siri as well.

Currently, the 'Ask...' feature is limited to the ChatGPT extension in the macOS 27 Golden Gate Release Candidate, and Claude is not yet supported. Additionally, the mechanism is implemented through private frameworks and is not exposed to general users.