Add Apple Intelligence provider (Phase 1 — on-device)

- New AppleFoundationProvider using FoundationModels framework (macOS 27+)
- Streaming via streamResponse(to:) → ResponseStream<String> snapshot deltas
- Session built with system prompt + conversation history injected as instructions text
- Full error mapping: context exceeded, guardrail violation, rate limit, availability states
- Settings.Provider.appleOnDevice case wired through ProviderRegistry, Color+Extensions, CreditsView
- inferProvider() detects "apple-" prefix model IDs
- Settings → General: Apple Intelligence section with live availability badge and deep link to System Settings

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

oAI/Models/Settings.swift

@@ -58,9 +58,16 @@ struct Settings: Codable {
         case anthropic
         case openai
         case ollama
+        case appleOnDevice = "apple_on_device"
 
         var displayName: String {
-            rawValue.capitalized
+            switch self {
+            case .openrouter:     return "OpenRouter"
+            case .anthropic:      return "Anthropic"
+            case .openai:         return "OpenAI"
+            case .ollama:         return "Ollama"
+            case .appleOnDevice:  return "Apple Intelligence"
+            }
         }
 
         var iconName: String {
@@ -69,6 +76,7 @@ struct Settings: Codable {
             case .anthropic:      return "brain"
             case .openai:         return "sparkles"
             case .ollama:         return "server.rack"
+            case .appleOnDevice:  return "apple.logo"
             }
         }
     }

oAI/Providers/AppleFoundationProvider.swift

@@ -0,0 +1,195 @@
+//
+//  AppleFoundationProvider.swift
+//  oAI
+//
+//  Apple Foundation Models provider (on-device Apple Intelligence)
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Copyright (C) 2026 Rune Olsen
+//
+// This file is part of oAI.
+//
+// oAI is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// oAI is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General
+// Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public
+// License along with oAI. If not, see <https://www.gnu.org/licenses/>.
+
+
+import Foundation
+import FoundationModels
+import os
+
+final class AppleFoundationProvider: AIProvider {
+    let name = "Apple Intelligence"
+
+    let capabilities = ProviderCapabilities(
+        supportsStreaming: true,
+        supportsVision: false,
+        supportsTools: false,
+        supportsOnlineSearch: false,
+        maxContextLength: 4096
+    )
+
+    // MARK: - Models
+
+    func listModels() async throws -> [ModelInfo] {
+        [
+            ModelInfo(
+                id: "apple-on-device",
+                name: "Apple On-Device",
+                description: "On-device Apple Intelligence model. Private, free, and works offline. 4K context window.",
+                contextLength: 4096,
+                pricing: ModelInfo.Pricing(prompt: 0, completion: 0),
+                capabilities: ModelInfo.ModelCapabilities(
+                    vision: false,
+                    tools: false,
+                    online: false
+                )
+            )
+        ]
+    }
+
+    func getModel(_ id: String) async throws -> ModelInfo? {
+        try await listModels().first { $0.id == id }
+    }
+
+    func getCredits() async throws -> Credits? { nil }
+
+    // MARK: - Streaming chat
+
+    func streamChat(request: ChatRequest) -> AsyncThrowingStream<StreamChunk, Error> {
+        AsyncThrowingStream { continuation in
+            Task {
+                do {
+                    let session = try self.makeSession(for: request)
+                    let prompt = self.lastUserMessage(from: request)
+
+                    // streamResponse(to: String) → ResponseStream<String>
+                    // Each snapshot.content is the full accumulated text so far (snapshot model).
+                    // We compute deltas by comparing each snapshot to the previous.
+                    let stream = session.streamResponse(to: prompt)
+                    var lastContent = ""
+
+                    for try await snapshot in stream {
+                        let current = snapshot.content
+                        if current.count > lastContent.count {
+                            let delta = String(current.dropFirst(lastContent.count))
+                            continuation.yield(StreamChunk(
+                                id: UUID().uuidString,
+                                model: request.model,
+                                delta: StreamChunk.Delta(content: delta, role: "assistant"),
+                                finishReason: nil,
+                                usage: nil
+                            ))
+                            lastContent = current
+                        }
+                    }
+
+                    continuation.yield(StreamChunk(
+                        id: UUID().uuidString,
+                        model: request.model,
+                        delta: StreamChunk.Delta(content: nil, role: nil),
+                        finishReason: "stop",
+                        usage: nil
+                    ))
+                    continuation.finish()
+
+                } catch let genError as LanguageModelSession.GenerationError {
+                    continuation.finish(throwing: self.mapGenerationError(genError))
+                } catch {
+                    continuation.finish(throwing: error)
+                }
+            }
+        }
+    }
+
+    // MARK: - Non-streaming chat
+
+    func chat(request: ChatRequest) async throws -> ChatResponse {
+        let session = try makeSession(for: request)
+        let prompt = lastUserMessage(from: request)
+        let response: LanguageModelSession.Response<String> = try await session.respond(to: prompt)
+        return ChatResponse(
+            id: UUID().uuidString,
+            model: request.model,
+            content: response.content,
+            role: "assistant",
+            finishReason: "stop",
+            usage: nil,
+            created: Date()
+        )
+    }
+
+    // MARK: - Tool messages (not supported in Phase 1)
+
+    func chatWithToolMessages(model: String, messages: [[String: Any]], tools: [Tool]?, maxTokens: Int?, temperature: Double?) async throws -> ChatResponse {
+        throw ProviderError.unknown("Tool calling requires Apple Foundation Models Phase 3.")
+    }
+
+    // MARK: - Session construction
+
+    private func makeSession(for request: ChatRequest) throws -> LanguageModelSession {
+        guard case .available = SystemLanguageModel.default.availability else {
+            throw availabilityError()
+        }
+
+        // Build instructions: system prompt + prior conversation turns as formatted text.
+        // Foundation Models sessions don't accept a message array — we inject history inline.
+        var instructions = request.systemPrompt ?? ""
+        let priorMessages = request.messages.dropLast().filter { $0.role != .system }
+
+        if !priorMessages.isEmpty {
+            let history = priorMessages
+                .map { m -> String in
+                    let label = m.role == .user ? "User" : "Assistant"
+                    return "\(label): \(m.content)"
+                }
+                .joined(separator: "\n")
+            instructions += "\n\nConversation so far:\n\(history)\n\nContinue from here."
+        }
+
+        return instructions.isEmpty
+            ? LanguageModelSession()
+            : LanguageModelSession(instructions: instructions)
+    }
+
+    private func lastUserMessage(from request: ChatRequest) -> String {
+        request.messages.last(where: { $0.role == .user })?.content ?? ""
+    }
+
+    // MARK: - Error mapping
+
+    private func availabilityError() -> Error {
+        switch SystemLanguageModel.default.availability {
+        case .unavailable(.deviceNotEligible):
+            return ProviderError.unknown("This Mac doesn't support Apple Intelligence. Apple Silicon is required.")
+        case .unavailable(.appleIntelligenceNotEnabled):
+            return ProviderError.unknown("Apple Intelligence is not enabled. Open System Settings → Apple Intelligence to turn it on.")
+        case .unavailable(.modelNotReady):
+            return ProviderError.unknown("Apple Intelligence model is still downloading. Please wait and try again.")
+        default:
+            return ProviderError.unknown("Apple Intelligence is not available on this device.")
+        }
+    }
+
+    private func mapGenerationError(_ error: LanguageModelSession.GenerationError) -> Error {
+        switch error {
+        case .exceededContextWindowSize:
+            return ProviderError.unknown("Apple Intelligence context limit exceeded (4,096 tokens). Start a new chat or enable Progressive Summarization in Settings → Advanced.")
+        case .rateLimited:
+            return ProviderError.rateLimitExceeded
+        case .guardrailViolation:
+            return ProviderError.unknown("Apple Intelligence declined to respond to this message.")
+        default:
+            return error
+        }
+    }
+}

oAI/Providers/ProviderRegistry.swift

@@ -69,6 +69,9 @@ class ProviderRegistry {
 
         case .ollama:
             provider = OllamaProvider(baseURL: settings.ollamaEffectiveURL)
+
+        case .appleOnDevice:
+            provider = AppleFoundationProvider()
         }
         
         // Cache and return
@@ -106,6 +109,8 @@ class ProviderRegistry {
             return settings.openaiAPIKey != nil && !settings.openaiAPIKey!.isEmpty
         case .ollama:
             return settings.ollamaConfigured
+        case .appleOnDevice:
+            return true  // no API key needed
         }
     }
 

oAI/Utilities/Extensions/Color+Extensions.swift

@@ -64,6 +64,7 @@ extension Color {
         case .anthropic:     return Color(hex: "#d4895a")  // Orange
         case .openai:        return Color(hex: "#10a37f")  // Green
         case .ollama:        return Color(hex: "#ffffff")  // White
+        case .appleOnDevice: return Color(hex: "#636366")  // Apple grey
         }
     }
     

oAI/ViewModels/ChatViewModel.swift

@@ -424,6 +424,8 @@ Don't narrate future actions ("Let me...") - just use the tools.
     func inferProviderPublic(from modelId: String) -> Settings.Provider? { inferProvider(from: modelId) }
 
     private func inferProvider(from modelId: String) -> Settings.Provider? {
+        // Apple Foundation Models
+        if modelId.hasPrefix("apple-") { return .appleOnDevice }
         // OpenRouter models always contain a "/" (e.g. "anthropic/claude-3-5-sonnet")
         if modelId.contains("/") { return .openrouter }
         // Anthropic direct (e.g. "claude-sonnet-4-5-20250929")

oAI/Views/Screens/CreditsView.swift

@@ -80,6 +80,17 @@ struct CreditsView: View {
                             .font(.system(size: 40))
                             .foregroundColor(.green)
                             .padding(.top)
+
+                    case .appleOnDevice:
+                        Text("Apple Intelligence")
+                            .font(.headline)
+                        Text("On-device and free — no credits or API key needed.")
+                            .font(.body)
+                            .foregroundColor(.secondary)
+                        Image(systemName: "apple.logo")
+                            .font(.system(size: 40))
+                            .foregroundColor(.secondary)
+                            .padding(.top)
                     }
                 }
 

oAI/Views/Screens/SettingsView.swift

@@ -25,6 +25,7 @@
 
 import SwiftUI
 import UniformTypeIdentifiers
+import FoundationModels
 
 struct SettingsView: View {
     @Environment(\.dismiss) var dismiss
@@ -306,6 +307,29 @@ It's better to admit "I need more information" or "I cannot do that" than to fak
             }
         }
 
+        // Apple Intelligence
+        VStack(alignment: .leading, spacing: 6) {
+            sectionHeader("Apple Intelligence")
+            formSection {
+                row("Status") {
+                    appleIntelligenceStatusBadge
+                }
+                rowDivider()
+                row("Model") {
+                    Text("On-Device (4K context)")
+                        .foregroundStyle(.secondary)
+                }
+                rowDivider()
+                row("") {
+                    Button("Open Apple Intelligence Settings") {
+                        if let url = URL(string: "x-apple.systempreferences:com.apple.preference.aisettings") {
+                            NSWorkspace.shared.open(url)
+                        }
+                    }
+                }
+            }
+        }
+
         // Features
         VStack(alignment: .leading, spacing: 6) {
             sectionHeader("Features")
@@ -2649,6 +2673,28 @@ It's better to admit "I need more information" or "I cannot do that" than to fak
         formatter.unitsStyle = .full
         return formatter.localizedString(for: date, relativeTo: .now)
     }
+
+    @ViewBuilder
+    private var appleIntelligenceStatusBadge: some View {
+        let availability = SystemLanguageModel.default.availability
+        switch availability {
+        case .available:
+            Label("Available", systemImage: "checkmark.circle.fill")
+                .foregroundStyle(.green)
+        case .unavailable(.deviceNotEligible):
+            Label("Not supported on this Mac", systemImage: "xmark.circle.fill")
+                .foregroundStyle(.red)
+        case .unavailable(.appleIntelligenceNotEnabled):
+            Label("Not enabled — open Apple Intelligence Settings", systemImage: "exclamationmark.circle.fill")
+                .foregroundStyle(.orange)
+        case .unavailable(.modelNotReady):
+            Label("Model downloading…", systemImage: "arrow.down.circle.fill")
+                .foregroundStyle(.orange)
+        default:
+            Label("Unavailable", systemImage: "questionmark.circle.fill")
+                .foregroundStyle(.secondary)
+        }
+    }
 }
 
 #Preview {