Add Anthropic prompt caching (direct + via OpenRouter)

Caches the system prompt/tools and growing conversation history via
cache_control breakpoints, cutting cost and latency on repeated turns.
Covers both the regular chat path and the tool-calling loop
(chatWithToolMessages), which has its own request-building code and was
initially missed. Cost calculation now accounts for cache write/read
pricing instead of treating all input tokens as full price. Verified
live: cache reads grow turn-over-turn in oAI.log.

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

.gitignore

@@ -4,6 +4,7 @@
 
 ## User settings
 xcuserdata/
+xcshareddata/
 
 ## compatibility with Xcode 8 and earlier (ignoring not required starting Xcode 9)
 *.xcscmblueprint

DEVELOPMENT.md

@@ -72,17 +72,6 @@ oAI/
 
 ## Building
 
-### Build Scripts
-
-| Script | Architecture | Output |
-|--------|-------------|--------|
-| `build.sh` | Apple Silicon (arm64) | Installs directly to `/Applications` |
-| `build-dmg.sh` | Apple Silicon (arm64) | `oAI-<version>-AppleSilicon.dmg` on Desktop |
-| `build-dmg-universal.sh` | Universal (arm64 + x86_64) | `oAI-<version>-Universal.dmg` on Desktop |
-| `build_nb/sv/da/de/en.sh` | Apple Silicon (arm64) | Build + launch in specific language |
-
-All scripts: find Developer ID cert, clean-build via `xcodebuild`, re-sign with `codesign --options runtime --timestamp`, verify. Version is read from `MARKETING_VERSION` in `project.pbxproj`.
-
 ### Manual Build Commands
 
 ```bash

README.md

@@ -332,9 +332,6 @@ This means you are free to use, study, modify, and distribute oAI, but any modif
 
 See [LICENSE](LICENSE) for the full license text, or visit [gnu.org/licenses/agpl-3.0](https://www.gnu.org/licenses/agpl-3.0.html).
 
-## Development
-
-See [DEVELOPMENT.md](DEVELOPMENT.md) for project structure, build scripts, database schema, and contribution guidelines.
 
 ## Author
 
@@ -344,9 +341,6 @@ See [DEVELOPMENT.md](DEVELOPMENT.md) for project structure, build scripts, datab
 - Blog: [https://blog.rune.pm](https://blog.rune.pm)
 - Gitlab.pm: [@rune](https://gitlab.pm/rune)
 
-## Contributing
-
-Contributions are welcome! See [DEVELOPMENT.md](DEVELOPMENT.md) for build instructions and project structure.
 
 ---
 

oAI.xcodeproj/xcshareddata/xcschemes/oAI.xcscheme

@@ -1,79 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<Scheme
-   LastUpgradeVersion = "2620"
-   version = "1.7">
-   <BuildAction
-      parallelizeBuildables = "YES"
-      buildImplicitDependencies = "YES"
-      buildArchitectures = "Automatic">
-      <BuildActionEntries>
-         <BuildActionEntry
-            buildForTesting = "YES"
-            buildForRunning = "YES"
-            buildForProfiling = "YES"
-            buildForArchiving = "YES"
-            buildForAnalyzing = "YES">
-            <BuildableReference
-               BuildableIdentifier = "primary"
-               BlueprintIdentifier = "A550A6612F3B72EA00136F2B"
-               BuildableName = "oAI.app"
-               BlueprintName = "oAI"
-               ReferencedContainer = "container:oAI.xcodeproj">
-            </BuildableReference>
-         </BuildActionEntry>
-      </BuildActionEntries>
-   </BuildAction>
-   <TestAction
-      buildConfiguration = "Debug"
-      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
-      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      shouldUseLaunchSchemeArgsEnv = "YES"
-      shouldAutocreateTestPlan = "YES">
-   </TestAction>
-   <LaunchAction
-      buildConfiguration = "Debug"
-      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
-      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      language = "en"
-      launchStyle = "0"
-      useCustomWorkingDirectory = "NO"
-      ignoresPersistentStateOnLaunch = "NO"
-      debugDocumentVersioning = "YES"
-      debugServiceExtension = "internal"
-      allowLocationSimulation = "YES">
-      <BuildableProductRunnable
-         runnableDebuggingMode = "0">
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "A550A6612F3B72EA00136F2B"
-            BuildableName = "oAI.app"
-            BlueprintName = "oAI"
-            ReferencedContainer = "container:oAI.xcodeproj">
-         </BuildableReference>
-      </BuildableProductRunnable>
-   </LaunchAction>
-   <ProfileAction
-      buildConfiguration = "Release"
-      shouldUseLaunchSchemeArgsEnv = "YES"
-      savedToolIdentifier = ""
-      useCustomWorkingDirectory = "NO"
-      debugDocumentVersioning = "YES">
-      <BuildableProductRunnable
-         runnableDebuggingMode = "0">
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "A550A6612F3B72EA00136F2B"
-            BuildableName = "oAI.app"
-            BlueprintName = "oAI"
-            ReferencedContainer = "container:oAI.xcodeproj">
-         </BuildableReference>
-      </BuildableProductRunnable>
-   </ProfileAction>
-   <AnalyzeAction
-      buildConfiguration = "Debug">
-   </AnalyzeAction>
-   <ArchiveAction
-      buildConfiguration = "Release"
-      revealArchiveInOrganizer = "YES">
-   </ArchiveAction>
-</Scheme>

oAI/Assets.xcassets/AccentColor.colorset/Contents.json

@@ -0,0 +1,20 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0xCA",
+          "green" : "0x7A",
+          "red" : "0x0A"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

oAI/Models/Conversation.swift

@@ -33,7 +33,7 @@ struct Conversation: Identifiable, Codable {
     var updatedAt: Date
     var primaryModel: String? // Primary model used in this conversation
 
-    init(
+    nonisolated init(
         id: UUID = UUID(),
         name: String,
         messages: [Message] = [],

oAI/Models/EmailLog.swift

@@ -44,7 +44,7 @@ struct EmailLog: Identifiable, Codable, Equatable {
     let responseTime: TimeInterval? // Time to generate response in seconds
     let modelId: String? // Model that handled the email
 
-    init(
+    nonisolated init(
         id: UUID = UUID(),
         timestamp: Date = Date(),
         sender: String,

oAI/Models/Message.swift

@@ -66,7 +66,7 @@ struct Message: Identifiable, Codable, Equatable {
     // Reasoning/thinking content (not persisted — in-memory only)
     var thinkingContent: String? = nil
 
-    init(
+    nonisolated init(
         id: UUID = UUID(),
         role: MessageRole,
         content: String,

oAI/Models/Settings.swift

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

oAI/Providers/AIProvider.swift

@@ -130,11 +130,23 @@ struct ChatResponse: Codable {
         let promptTokens: Int
         let completionTokens: Int
         let totalTokens: Int
+        let cacheCreationInputTokens: Int?
+        let cacheReadInputTokens: Int?
+
+        init(promptTokens: Int, completionTokens: Int, totalTokens: Int, cacheCreationInputTokens: Int? = nil, cacheReadInputTokens: Int? = nil) {
+            self.promptTokens = promptTokens
+            self.completionTokens = completionTokens
+            self.totalTokens = totalTokens
+            self.cacheCreationInputTokens = cacheCreationInputTokens
+            self.cacheReadInputTokens = cacheReadInputTokens
+        }
 
         enum CodingKeys: String, CodingKey {
             case promptTokens = "prompt_tokens"
             case completionTokens = "completion_tokens"
             case totalTokens = "total_tokens"
+            case cacheCreationInputTokens = "cache_creation_input_tokens"
+            case cacheReadInputTokens = "cache_read_input_tokens"
         }
     }
 

oAI/Providers/AnthropicProvider.swift

@@ -77,6 +77,15 @@ class AnthropicProvider: AIProvider {
     /// falls back to prefix matching so newly-released model variants (e.g. "claude-sonnet-4-6-20260301")
     /// still inherit the correct pricing tier.
     private static let knownModels: [ModelInfo] = [
+        // Claude Fable 5
+        ModelInfo(
+            id: "claude-fable-5",
+            name: "Claude Fable 5",
+            description: "Anthropic's creative and storytelling model",
+            contextLength: 200_000,
+            pricing: .init(prompt: 10.0, completion: 50.0),
+            capabilities: .init(vision: true, tools: true, online: true)
+        ),
         // Claude 4.x series
         ModelInfo(
             id: "claude-opus-4-6",
@@ -173,6 +182,7 @@ class AnthropicProvider: AIProvider {
     /// Pricing tiers used for fuzzy fallback matching on unknown model IDs.
     /// Keyed by model name prefix (longest match wins).
     private static let pricingFallback: [(prefix: String, prompt: Double, completion: Double)] = [
+        ("claude-fable",  10.0, 50.0),
         ("claude-opus",   15.0, 75.0),
         ("claude-sonnet",  3.0, 15.0),
         ("claude-haiku",   0.80, 4.0),
@@ -356,6 +366,19 @@ class AnthropicProvider: AIProvider {
             }
         }
 
+        // Mark the last message with a cache breakpoint so the next loop
+        // iteration (or next turn) can reuse everything up through this one.
+        if var lastMessage = conversationMessages.popLast() {
+            if let content = lastMessage["content"] as? String {
+                lastMessage["content"] = [["type": "text", "text": content, "cache_control": ["type": "ephemeral"]]]
+            } else if var blocks = lastMessage["content"] as? [[String: Any]], var lastBlock = blocks.popLast() {
+                lastBlock["cache_control"] = ["type": "ephemeral"]
+                blocks.append(lastBlock)
+                lastMessage["content"] = blocks
+            }
+            conversationMessages.append(lastMessage)
+        }
+
         var body: [String: Any] = [
             "model": model,
             "messages": conversationMessages,
@@ -363,7 +386,9 @@ class AnthropicProvider: AIProvider {
             "stream": false
         ]
         if let systemText = systemText {
-            body["system"] = systemText
+            // Array form carries a cache breakpoint; also covers tools, which
+            // render before system in Anthropic's prefix order.
+            body["system"] = [["type": "text", "text": systemText, "cache_control": ["type": "ephemeral"]]]
         }
         if let temperature = temperature {
             body["temperature"] = temperature
@@ -430,6 +455,8 @@ class AnthropicProvider: AIProvider {
                     var currentId = ""
                     var currentModel = request.model
                     var inputTokens = 0
+                    var cacheCreationTokens: Int? = nil
+                    var cacheReadTokens: Int? = nil
 
                     for try await line in bytes.lines {
                         // Anthropic SSE: "event: ..." and "data: {...}"
@@ -449,6 +476,11 @@ class AnthropicProvider: AIProvider {
                                 currentModel = message["model"] as? String ?? request.model
                                 if let usageDict = message["usage"] as? [String: Any] {
                                     inputTokens = usageDict["input_tokens"] as? Int ?? 0
+                                    cacheCreationTokens = usageDict["cache_creation_input_tokens"] as? Int
+                                    cacheReadTokens = usageDict["cache_read_input_tokens"] as? Int
+                                    if cacheCreationTokens != nil || cacheReadTokens != nil {
+                                        Log.api.info("Anthropic stream cache usage: input=\(inputTokens), created=\(cacheCreationTokens ?? 0), read=\(cacheReadTokens ?? 0)")
+                                    }
                                 }
                             }
 
@@ -472,7 +504,13 @@ class AnthropicProvider: AIProvider {
                             var usage: ChatResponse.Usage? = nil
                             if let usageDict = event["usage"] as? [String: Any] {
                                 let outputTokens = usageDict["output_tokens"] as? Int ?? 0
-                                usage = ChatResponse.Usage(promptTokens: inputTokens, completionTokens: outputTokens, totalTokens: inputTokens + outputTokens)
+                                usage = ChatResponse.Usage(
+                                    promptTokens: inputTokens,
+                                    completionTokens: outputTokens,
+                                    totalTokens: inputTokens + outputTokens,
+                                    cacheCreationInputTokens: cacheCreationTokens,
+                                    cacheReadInputTokens: cacheReadTokens
+                                )
                             }
                             continuation.yield(StreamChunk(
                                 id: currentId,
@@ -582,6 +620,19 @@ class AnthropicProvider: AIProvider {
             }
         }
 
+        // Mark the last message with a cache breakpoint so the next turn can
+        // reuse everything up through this one as a cached prefix.
+        if var lastMessage = apiMessages.popLast() {
+            if let content = lastMessage["content"] as? String {
+                lastMessage["content"] = [["type": "text", "text": content, "cache_control": ["type": "ephemeral"]]]
+            } else if var blocks = lastMessage["content"] as? [[String: Any]], var lastBlock = blocks.popLast() {
+                lastBlock["cache_control"] = ["type": "ephemeral"]
+                blocks.append(lastBlock)
+                lastMessage["content"] = blocks
+            }
+            apiMessages.append(lastMessage)
+        }
+
         var body: [String: Any] = [
             "model": request.model,
             "messages": apiMessages,
@@ -590,7 +641,10 @@ class AnthropicProvider: AIProvider {
         ]
 
         if let systemText = systemText {
-            body["system"] = systemText
+            // Array form (rather than a plain string) carries a cache breakpoint.
+            // Per Anthropic's render order (tools -> system -> messages), this
+            // single breakpoint caches the tool definitions too.
+            body["system"] = [["type": "text", "text": systemText, "cache_control": ["type": "ephemeral"]]]
         }
         if let temperature = request.temperature {
             body["temperature"] = temperature
@@ -665,6 +719,11 @@ class AnthropicProvider: AIProvider {
         let usageDict = json["usage"] as? [String: Any]
         let inputTokens = usageDict?["input_tokens"] as? Int ?? 0
         let outputTokens = usageDict?["output_tokens"] as? Int ?? 0
+        let cacheCreationTokens = usageDict?["cache_creation_input_tokens"] as? Int
+        let cacheReadTokens = usageDict?["cache_read_input_tokens"] as? Int
+        if cacheCreationTokens != nil || cacheReadTokens != nil {
+            Log.api.info("Anthropic cache usage: input=\(inputTokens), created=\(cacheCreationTokens ?? 0), read=\(cacheReadTokens ?? 0)")
+        }
 
         return ChatResponse(
             id: id,
@@ -675,7 +734,9 @@ class AnthropicProvider: AIProvider {
             usage: ChatResponse.Usage(
                 promptTokens: inputTokens,
                 completionTokens: outputTokens,
-                totalTokens: inputTokens + outputTokens
+                totalTokens: inputTokens + outputTokens,
+                cacheCreationInputTokens: cacheCreationTokens,
+                cacheReadInputTokens: cacheReadTokens
             ),
             created: Date(),
             toolCalls: toolCalls.isEmpty ? nil : toolCalls

oAI/Providers/AppleFoundationProvider.swift

@@ -1,195 +0,0 @@
-//
-//  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/OpenRouterModels.swift

@@ -48,6 +48,11 @@ struct OpenRouterChatRequest: Codable {
     let toolChoice: String?
     let modalities: [String]?
     let reasoning: ReasoningAPIConfig?
+    let cacheControl: CacheControl?
+
+    struct CacheControl: Codable {
+        let type: String
+    }
 
     struct APIMessage: Codable {
         let role: String
@@ -138,6 +143,7 @@ struct OpenRouterChatRequest: Codable {
         case toolChoice = "tool_choice"
         case modalities
         case reasoning
+        case cacheControl = "cache_control"
     }
 }
 
@@ -225,11 +231,23 @@ struct OpenRouterChatResponse: Codable {
         let promptTokens: Int
         let completionTokens: Int
         let totalTokens: Int
+        let promptTokensDetails: PromptTokensDetails?
+
+        struct PromptTokensDetails: Codable {
+            let cachedTokens: Int?
+            let cacheWriteTokens: Int?
+
+            enum CodingKeys: String, CodingKey {
+                case cachedTokens = "cached_tokens"
+                case cacheWriteTokens = "cache_write_tokens"
+            }
+        }
 
         enum CodingKeys: String, CodingKey {
             case promptTokens = "prompt_tokens"
             case completionTokens = "completion_tokens"
             case totalTokens = "total_tokens"
+            case promptTokensDetails = "prompt_tokens_details"
         }
     }
 }

oAI/Providers/OpenRouterProvider.swift

@@ -198,6 +198,11 @@ class OpenRouterProvider: AIProvider {
         }
         if let maxTokens = maxTokens { body["max_tokens"] = maxTokens }
         if let temperature = temperature { body["temperature"] = temperature }
+        // Anthropic models require an explicit cache_control opt-in on OpenRouter;
+        // other providers cache automatically.
+        if model.hasPrefix("anthropic/") {
+            body["cache_control"] = ["type": "ephemeral"]
+        }
 
         var urlRequest = URLRequest(url: url)
         urlRequest.httpMethod = "POST"
@@ -388,6 +393,12 @@ class OpenRouterProvider: AIProvider {
             ReasoningAPIConfig(effort: $0.effort, exclude: $0.exclude ? true : nil)
         }
 
+        // Anthropic models require an explicit cache_control opt-in on OpenRouter;
+        // other providers (OpenAI, DeepSeek, Gemini, Grok, etc.) cache automatically.
+        let cacheControl: OpenRouterChatRequest.CacheControl? = effectiveModel.hasPrefix("anthropic/")
+            ? .init(type: "ephemeral")
+            : nil
+
         return OpenRouterChatRequest(
             model: effectiveModel,
             messages: apiMessages,
@@ -398,7 +409,8 @@ class OpenRouterProvider: AIProvider {
             tools: request.tools,
             toolChoice: request.tools != nil ? "auto" : nil,
             modalities: request.imageGeneration ? ["text", "image"] : nil,
-            reasoning: reasoningConfig
+            reasoning: reasoningConfig,
+            cacheControl: cacheControl
         )
     }
     
@@ -416,6 +428,11 @@ class OpenRouterProvider: AIProvider {
         let allImages = topLevelImages + blockImages
         let images: [Data]? = allImages.isEmpty ? nil : allImages
 
+        if let details = apiResponse.usage?.promptTokensDetails,
+           details.cachedTokens != nil || details.cacheWriteTokens != nil {
+            Log.api.info("OpenRouter cache usage: model=\(apiResponse.model), created=\(details.cacheWriteTokens ?? 0), read=\(details.cachedTokens ?? 0)")
+        }
+
         return ChatResponse(
             id: apiResponse.id,
             model: apiResponse.model,
@@ -426,7 +443,9 @@ class OpenRouterProvider: AIProvider {
                 ChatResponse.Usage(
                     promptTokens: usage.promptTokens,
                     completionTokens: usage.completionTokens,
-                    totalTokens: usage.totalTokens
+                    totalTokens: usage.totalTokens,
+                    cacheCreationInputTokens: usage.promptTokensDetails?.cacheWriteTokens,
+                    cacheReadInputTokens: usage.promptTokensDetails?.cachedTokens
                 )
             },
             created: Date(timeIntervalSince1970: TimeInterval(apiResponse.created)),
@@ -446,6 +465,11 @@ class OpenRouterProvider: AIProvider {
         let allImages = topLevelImages + blockImages
         let images: [Data]? = allImages.isEmpty ? nil : allImages
 
+        if let details = apiChunk.usage?.promptTokensDetails,
+           details.cachedTokens != nil || details.cacheWriteTokens != nil {
+            Log.api.info("OpenRouter stream cache usage: model=\(apiChunk.model), created=\(details.cacheWriteTokens ?? 0), read=\(details.cachedTokens ?? 0)")
+        }
+
         return StreamChunk(
             id: apiChunk.id,
             model: apiChunk.model,
@@ -460,7 +484,9 @@ class OpenRouterProvider: AIProvider {
                 ChatResponse.Usage(
                     promptTokens: usage.promptTokens,
                     completionTokens: usage.completionTokens,
-                    totalTokens: usage.totalTokens
+                    totalTokens: usage.totalTokens,
+                    cacheCreationInputTokens: usage.promptTokensDetails?.cacheWriteTokens,
+                    cacheReadInputTokens: usage.promptTokensDetails?.cachedTokens
                 )
             }
         )

oAI/Providers/ProviderRegistry.swift

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

oAI/Services/ConversationMergeService.swift

@@ -0,0 +1,193 @@
+//
+//  ConversationMergeService.swift
+//  oAI
+//
+//  Combine multiple saved conversations into one (simple concatenation or AI-assisted merge)
+//
+// 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 os
+
+enum CombineMode: String, Sendable {
+    case simple
+    case ai
+}
+
+enum MergeError: LocalizedError {
+    case tooFewConversations
+    case noDefaultModel
+    case noAPIKey
+    case invalidAIResponse(String)
+
+    var errorDescription: String? {
+        switch self {
+        case .tooFewConversations:
+            return "Select at least two conversations to combine."
+        case .noDefaultModel:
+            return "No default model is configured. Set one in Settings → General → Default Model."
+        case .noAPIKey:
+            return "No API key configured for the default provider. Add one in Settings."
+        case .invalidAIResponse(let snippet):
+            return "The model's response could not be parsed into a conversation: \(snippet)"
+        }
+    }
+}
+
+enum ConversationMergeService {
+
+    static func merge(
+        conversationIds: [UUID],
+        name: String,
+        mode: CombineMode,
+        deleteOriginals: Bool
+    ) async throws -> Conversation {
+        guard conversationIds.count >= 2 else {
+            throw MergeError.tooFewConversations
+        }
+
+        let sources: [(Conversation, [Message])] = try conversationIds.compactMap { id in
+            try DatabaseService.shared.loadConversation(id: id)
+        }
+
+        // The model used in the merged conversation should reflect the most recently used
+        // model across the *source* conversations — never the model that performed the merge.
+        let latestModelId = sources
+            .flatMap { $0.1 }
+            .filter { $0.modelId != nil }
+            .max { $0.timestamp < $1.timestamp }?
+            .modelId
+
+        let mergedMessages: [Message]
+        switch mode {
+        case .simple:
+            mergedMessages = simpleMerge(sources)
+        case .ai:
+            mergedMessages = try await aiMerge(sources)
+        }
+
+        let newConversation = try DatabaseService.shared.saveConversation(
+            id: UUID(),
+            name: name,
+            messages: mergedMessages,
+            primaryModel: latestModelId
+        )
+
+        if deleteOriginals {
+            for id in conversationIds {
+                _ = try? DatabaseService.shared.deleteConversation(id: id)
+            }
+        }
+
+        Log.db.info("Combined \(conversationIds.count) conversations into '\(name)' (mode: \(mode.rawValue), deleteOriginals: \(deleteOriginals))")
+
+        return newConversation
+    }
+
+    private static func simpleMerge(_ sources: [(Conversation, [Message])]) -> [Message] {
+        sources.flatMap { $0.1 }.sorted { $0.timestamp < $1.timestamp }
+    }
+
+    private struct MergedTurn: Codable {
+        let role: String
+        let content: String
+    }
+
+    private static func aiMerge(_ sources: [(Conversation, [Message])]) async throws -> [Message] {
+        let settings = SettingsService.shared
+        guard let modelId = settings.defaultModel, !modelId.isEmpty else {
+            throw MergeError.noDefaultModel
+        }
+        guard let provider = ProviderRegistry.shared.getProvider(for: settings.defaultProvider) else {
+            throw MergeError.noAPIKey
+        }
+
+        let transcript = sources.map { conversation, messages -> String in
+            let body = messages.map { msg -> String in
+                let label = msg.role == .user ? "**User:**" : "**Assistant:**"
+                return "\(label) \(msg.content)"
+            }.joined(separator: "\n\n")
+            return "### Conversation: \(conversation.name)\n\n\(body)"
+        }.joined(separator: "\n\n---\n\n")
+
+        let mergePrompt = """
+        Merge the following saved conversation transcripts into a single, coherent conversation. \
+        Remove redundant or duplicate exchanges, keep the most informative answer when sources overlap, \
+        preserve important details from each source, and do not invent facts that were not in the originals.
+
+        Respond with ONLY a JSON array of message objects in logical order, each in the form \
+        {"role": "user" or "assistant", "content": "..."}. Do not include any text outside the JSON array.
+
+        \(transcript)
+        """
+
+        let request = ChatRequest(
+            messages: [Message(role: .user, content: mergePrompt)],
+            model: modelId,
+            stream: false,
+            maxTokens: 4000,
+            temperature: 0.3,
+            topP: nil,
+            systemPrompt: "You are a helpful assistant that merges chat conversation transcripts into one clean, coherent conversation.",
+            tools: nil,
+            onlineMode: false,
+            imageGeneration: false
+        )
+
+        let response: ChatResponse
+        do {
+            response = try await provider.chat(request: request)
+        } catch {
+            Log.api.error("Conversation merge AI call failed: \(error.localizedDescription)")
+            throw error
+        }
+
+        let turns = try parseTurns(from: response.content)
+
+        // modelId intentionally left nil here: these messages are a synthesized composite,
+        // not output from a single source model. The conversation's primaryModel (set by the
+        // caller from the source conversations) is what drives the model shown in the list.
+        let base = Date()
+        return turns.enumerated().map { index, turn in
+            Message(
+                role: turn.role == "user" ? .user : .assistant,
+                content: turn.content,
+                timestamp: base.addingTimeInterval(TimeInterval(index))
+            )
+        }
+    }
+
+    private static func parseTurns(from raw: String) throws -> [MergedTurn] {
+        var text = raw.trimmingCharacters(in: .whitespacesAndNewlines)
+        if text.hasPrefix("```") {
+            text = text.components(separatedBy: "\n").dropFirst().joined(separator: "\n")
+            if text.hasSuffix("```") {
+                text = String(text.dropLast(3))
+            }
+            text = text.trimmingCharacters(in: .whitespacesAndNewlines)
+        }
+        guard let data = text.data(using: .utf8),
+              let turns = try? JSONDecoder().decode([MergedTurn].self, from: data),
+              !turns.isEmpty else {
+            throw MergeError.invalidAIResponse(String(raw.prefix(200)))
+        }
+        return turns
+    }
+}

oAI/Services/EncryptionService.swift

@@ -31,12 +31,11 @@ import IOKit
 class EncryptionService {
     nonisolated static let shared = EncryptionService()
 
-    private let salt = "oAI-secure-storage-v1" // App-specific salt
-    private lazy var encryptionKey: SymmetricKey = {
-        deriveEncryptionKey()
-    }()
+    private let encryptionKey: SymmetricKey
 
-    private init() {}
+    private init() {
+        self.encryptionKey = Self.deriveEncryptionKey()
+    }
 
     // MARK: - Public Interface
 
@@ -73,19 +72,17 @@ class EncryptionService {
     // MARK: - Key Derivation
 
     /// Derive encryption key from machine-specific data
-    private func deriveEncryptionKey() -> SymmetricKey {
-        // Combine machine UUID + bundle ID + salt for key material
+    private static func deriveEncryptionKey() -> SymmetricKey {
         let machineUUID = getMachineUUID()
         let bundleID = Bundle.main.bundleIdentifier ?? "com.oai.oAI"
+        let salt = "oAI-secure-storage-v1"
         let keyMaterial = "\(machineUUID)-\(bundleID)-\(salt)"
-
-        // Hash to create consistent 256-bit key
         let hash = SHA256.hash(data: Data(keyMaterial.utf8))
         return SymmetricKey(data: hash)
     }
 
     /// Get machine-specific UUID (IOPlatformUUID)
-    private func getMachineUUID() -> String {
+    private static func getMachineUUID() -> String {
         // Get IOPlatformUUID from IOKit
         let platformExpert = IOServiceGetMatchingService(
             kIOMainPortDefault,

oAI/Utilities/Extensions/Color+Extensions.swift

@@ -64,7 +64,6 @@ 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/Utilities/Logging.swift

@@ -52,7 +52,7 @@ enum LogLevel: Int, Comparable, CaseIterable, Sendable {
         }
     }
 
-    static func < (lhs: LogLevel, rhs: LogLevel) -> Bool {
+    nonisolated static func < (lhs: LogLevel, rhs: LogLevel) -> Bool {
         lhs.rawValue < rhs.rawValue
     }
 }
@@ -60,7 +60,7 @@ enum LogLevel: Int, Comparable, CaseIterable, Sendable {
 // MARK: - File Logger
 
 final class FileLogger: @unchecked Sendable {
-    static let shared = FileLogger()
+    nonisolated static let shared = FileLogger()
 
     private let fileHandle: FileHandle?
     private let queue = DispatchQueue(label: "com.oai.filelogger")
@@ -70,8 +70,8 @@ final class FileLogger: @unchecked Sendable {
         return f
     }()
 
-    /// Current minimum log level (read from UserDefaults for thread safety)
-    var minimumLevel: LogLevel {
+    /// Current minimum log level (backed by UserDefaults — thread-safe).
+    nonisolated var minimumLevel: LogLevel {
         get {
             let raw = UserDefaults.standard.integer(forKey: "logLevel")
             return LogLevel(rawValue: raw) ?? .info
@@ -95,7 +95,7 @@ final class FileLogger: @unchecked Sendable {
         fileHandle?.seekToEndOfFile()
     }
 
-    func write(_ level: LogLevel, category: String, message: String) {
+    nonisolated func write(_ level: LogLevel, category: String, message: String) {
         guard level >= minimumLevel else { return }
         queue.async { [weak self] in
             guard let self, let fh = self.fileHandle else { return }

oAI/ViewModels/ChatViewModel.swift

@@ -424,8 +424,6 @@ 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")
@@ -936,10 +934,7 @@ Don't narrate future actions ("Let me...") - just use the tools.
                             messages[index].tokens = usage.completionTokens
                             if let model = selectedModel {
                                 let hasPricing = model.pricing.prompt > 0 || model.pricing.completion > 0
-                                let cost: Double? = hasPricing
-                                    ? (Double(usage.promptTokens) * model.pricing.prompt / 1_000_000) +
-                                      (Double(usage.completionTokens) * model.pricing.completion / 1_000_000)
-                                    : nil
+                                let cost: Double? = hasPricing ? calculateCost(usage: usage, pricing: model.pricing) : nil
                                 messages[index].cost = cost
                                 sessionStats.addMessage(inputTokens: usage.promptTokens, outputTokens: usage.completionTokens, cost: cost)
                             }
@@ -1003,10 +998,7 @@ Don't narrate future actions ("Let me...") - just use the tools.
                             messages[index].tokens = usage.completionTokens
                             if let model = selectedModel {
                                 let hasPricing = model.pricing.prompt > 0 || model.pricing.completion > 0
-                                let cost: Double? = hasPricing
-                                    ? (Double(usage.promptTokens) * model.pricing.prompt / 1_000_000) +
-                                      (Double(usage.completionTokens) * model.pricing.completion / 1_000_000)
-                                    : nil
+                                let cost: Double? = hasPricing ? calculateCost(usage: usage, pricing: model.pricing) : nil
                                 messages[index].cost = cost
                                 sessionStats.addMessage(inputTokens: usage.promptTokens, outputTokens: usage.completionTokens, cost: cost)
                             }
@@ -1531,10 +1523,7 @@ Don't narrate future actions ("Let me...") - just use the tools.
                 // Calculate cost
                 if let usage = totalUsage, let model = selectedModel {
                     let hasPricing = model.pricing.prompt > 0 || model.pricing.completion > 0
-                    let cost: Double? = hasPricing
-                        ? (Double(usage.promptTokens) * model.pricing.prompt / 1_000_000) +
-                          (Double(usage.completionTokens) * model.pricing.completion / 1_000_000)
-                        : nil
+                    let cost: Double? = hasPricing ? calculateCost(usage: usage, pricing: model.pricing) : nil
                     if let index = messages.lastIndex(where: { $0.id == assistantMessage.id }) {
                         messages[index].cost = cost
                     }
@@ -2182,6 +2171,18 @@ Don't narrate future actions ("Let me...") - just use the tools.
         }
     }
 
+    /// Cost for one response's usage, accounting for Anthropic-style prompt-cache
+    /// pricing when present: cache writes cost 1.25x the base input rate, cache
+    /// reads cost 0.1x. `usage.promptTokens` is already the uncached remainder —
+    /// it does not need cache tokens subtracted from it.
+    private func calculateCost(usage: ChatResponse.Usage, pricing: ModelInfo.Pricing) -> Double {
+        let inputCost = Double(usage.promptTokens) * pricing.prompt / 1_000_000
+        let cacheReadCost = Double(usage.cacheReadInputTokens ?? 0) * pricing.prompt * 0.1 / 1_000_000
+        let cacheWriteCost = Double(usage.cacheCreationInputTokens ?? 0) * pricing.prompt * 1.25 / 1_000_000
+        let outputCost = Double(usage.completionTokens) * pricing.completion / 1_000_000
+        return inputCost + cacheReadCost + cacheWriteCost + outputCost
+    }
+
     /// Summarize a chunk of messages into a concise summary
     private func summarizeMessageChunk(_ messages: [Message]) async -> String? {
         guard let provider = providerRegistry.getProvider(for: currentProvider),

oAI/Views/Main/ChatView.swift

@@ -38,7 +38,10 @@ struct ChatView: View {
                 provider: viewModel.currentProvider,
                 model: viewModel.selectedModel,
                 onModelSelect: onModelSelect,
-                onProviderChange: onProviderChange
+                onProviderChange: onProviderChange,
+                conversationName: viewModel.currentConversationName,
+                hasUnsavedChanges: viewModel.hasUnsavedChanges,
+                onQuickSave: viewModel.quickSave
             )
 
             // Messages

oAI/Views/Main/FooterView.swift

@@ -93,15 +93,6 @@ struct FooterView: View {
             }
             #endif
 
-            // Save indicator (only when chat has messages)
-            if stats.messageCount > 0 {
-                SaveIndicator(
-                    conversationName: conversationName,
-                    hasUnsavedChanges: hasUnsavedChanges,
-                    onSave: onQuickSave
-                )
-            }
-
             // Update available badge (shows only when an update exists — no version number)
             #if os(macOS)
             UpdateBadge()

oAI/Views/Main/HeaderView.swift

@@ -31,12 +31,66 @@ struct HeaderView: View {
     let model: ModelInfo?
     let onModelSelect: () -> Void
     let onProviderChange: (Settings.Provider) -> Void
+    var conversationName: String? = nil
+    var hasUnsavedChanges: Bool = false
+    var onQuickSave: (() -> Void)? = nil
     private let settings = SettingsService.shared
     private let registry = ProviderRegistry.shared
 
     var body: some View {
+        ZStack {
+            // Left: provider + model + star
             HStack(spacing: 12) {
-            // Provider picker dropdown — only shows configured providers
+                providerMenu
+                modelButton
+                starButton
+                Spacer()
+            }
+
+            // Center: conversation title (macOS document-title style)
+            conversationTitle
+        }
+        .padding(.horizontal, 16)
+        .padding(.vertical, 8)
+        .background(.ultraThinMaterial)
+        .overlay(
+            Rectangle()
+                .fill(Color.oaiBorder.opacity(0.5))
+                .frame(height: 1),
+            alignment: .bottom
+        )
+    }
+
+    // MARK: - Conversation title (center)
+
+    @ViewBuilder
+    private var conversationTitle: some View {
+        if let name = conversationName {
+            Button(action: { if hasUnsavedChanges { onQuickSave?() } }) {
+                HStack(spacing: 5) {
+                    if hasUnsavedChanges {
+                        Circle()
+                            .fill(Color.orange)
+                            .frame(width: 6, height: 6)
+                    }
+                    Text(name)
+                        .font(.system(size: settings.guiTextSize - 1, weight: .medium))
+                        .foregroundColor(.oaiPrimary)
+                        .lineLimit(1)
+                        .frame(maxWidth: 300)
+                }
+            }
+            .buttonStyle(.plain)
+            .disabled(!hasUnsavedChanges)
+            .help(hasUnsavedChanges ? "Unsaved changes — click to save" : "Saved")
+            .animation(.easeInOut(duration: 0.2), value: hasUnsavedChanges)
+            .animation(.easeInOut(duration: 0.2), value: name)
+        }
+    }
+
+    // MARK: - Subviews (extracted so ZStack stays readable)
+
+    private var providerMenu: some View {
         Menu {
             ForEach(registry.configuredProviders, id: \.self) { p in
                 Button {
@@ -45,9 +99,7 @@ struct HeaderView: View {
                     HStack {
                         Image(systemName: p.iconName)
                         Text(p.displayName)
-                            if p == provider {
-                                Image(systemName: "checkmark")
-                            }
+                        if p == provider { Image(systemName: "checkmark") }
                     }
                 }
             }
@@ -70,58 +122,46 @@ struct HeaderView: View {
         .menuStyle(.borderlessButton)
         .fixedSize()
         .help("Switch provider")
+    }
 
-            // Model name (clickable → model selector)
+    private var modelButton: some View {
         Button(action: onModelSelect) {
             if let model = model {
                 HStack(spacing: 6) {
                     Text(model.name)
                         .font(.system(size: settings.guiTextSize, weight: .medium))
                         .foregroundColor(.oaiPrimary)
-
-                        // Capability badges
                     HStack(spacing: 3) {
                         if model.capabilities.vision {
-                                Image(systemName: "eye")
-                                    .font(.system(size: 9))
-                                    .foregroundColor(.oaiSecondary)
+                            Image(systemName: "eye").font(.system(size: 9)).foregroundColor(.oaiSecondary)
                         }
                         if model.capabilities.tools {
-                                Image(systemName: "wrench")
-                                    .font(.system(size: 9))
-                                    .foregroundColor(.oaiSecondary)
+                            Image(systemName: "wrench").font(.system(size: 9)).foregroundColor(.oaiSecondary)
                         }
                         if model.capabilities.online {
-                                Image(systemName: "globe")
-                                    .font(.system(size: 9))
-                                    .foregroundColor(.oaiSecondary)
+                            Image(systemName: "globe").font(.system(size: 9)).foregroundColor(.oaiSecondary)
                         }
                         if model.capabilities.imageGeneration {
-                                Image(systemName: "paintbrush")
-                                    .font(.system(size: 9))
-                                    .foregroundColor(.oaiSecondary)
+                            Image(systemName: "paintbrush").font(.system(size: 9)).foregroundColor(.oaiSecondary)
                         }
                     }
-
-                        Image(systemName: "chevron.down")
-                            .font(.caption2)
-                            .foregroundColor(.oaiSecondary)
+                    Image(systemName: "chevron.down").font(.caption2).foregroundColor(.oaiSecondary)
                 }
             } else {
                 HStack(spacing: 4) {
                     Text("No model selected")
                         .font(.system(size: settings.guiTextSize))
                         .foregroundColor(.oaiSecondary)
-                        Image(systemName: "chevron.down")
-                            .font(.caption2)
-                            .foregroundColor(.oaiSecondary)
+                    Image(systemName: "chevron.down").font(.caption2).foregroundColor(.oaiSecondary)
                 }
             }
         }
         .buttonStyle(.plain)
         .help("Select model")
+    }
 
-            // Favourite star
+    @ViewBuilder
+    private var starButton: some View {
         if let model = model {
             let isFav = settings.favoriteModelIds.contains(model.id)
             Button(action: { settings.toggleFavoriteModel(model.id) }) {
@@ -132,18 +172,6 @@ struct HeaderView: View {
             .buttonStyle(.plain)
             .help(isFav ? "Remove from favorites" : "Add to favorites")
         }
-
-            Spacer()
-        }
-        .padding(.horizontal, 16)
-        .padding(.vertical, 8)
-        .background(.ultraThinMaterial)
-        .overlay(
-            Rectangle()
-                .fill(Color.oaiBorder.opacity(0.5))
-                .frame(height: 1),
-            alignment: .bottom
-        )
     }
 }
 

oAI/Views/Main/InputBar.swift

@@ -44,7 +44,7 @@ struct InputBar: View {
 
     @State private var showCommandDropdown = false
     @State private var selectedSuggestionIndex: Int = 0
-    @FocusState private var isInputFocused: Bool
+    @State private var isInputFocused: Bool = false
 
     private static let minInputHeight: CGFloat = 56
     private static let maxInputHeight: CGFloat = 320
@@ -95,55 +95,50 @@ struct InputBar: View {
                     }
 
                     // Editor — fills the fixed-height box, bottom area reserved for globe
-                    TextEditor(text: $text)
-                        .font(.system(size: settings.inputTextSize))
-                        .foregroundColor(.oaiPrimary)
-                        .scrollContentBackground(.hidden)
-                        .padding(.horizontal, 8)
-                        .padding(.top, 6)
-                        .padding(.bottom, 30)
-                        .frame(maxWidth: .infinity, maxHeight: .infinity)
-                        .focused($isInputFocused)
-                        .onChange(of: text) {
-                            showCommandDropdown = text.hasPrefix("/")
-                            selectedSuggestionIndex = 0
-                        }
-                        #if os(macOS)
-                        .onKeyPress(.upArrow) {
-                            if showCommandDropdown && selectedSuggestionIndex > 0 {
-                                selectedSuggestionIndex -= 1
-                                return .handled
-                            }
-                            return .ignored
-                        }
-                        .onKeyPress(.downArrow) {
-                            if showCommandDropdown {
-                                let count = CommandSuggestionsView.filteredCommands(for: text).count
-                                if selectedSuggestionIndex < count - 1 {
-                                    selectedSuggestionIndex += 1
-                                    return .handled
-                                }
-                            }
-                            return .ignored
-                        }
-                        .onKeyPress(.escape) {
-                            if showCommandDropdown { showCommandDropdown = false; return .handled }
-                            if isGenerating { onCancel(); return .handled }
-                            return .ignored
-                        }
-                        .onKeyPress(.return, phases: .down) { press in
-                            if press.modifiers.contains(.shift) { return .ignored }
+                    NativeTextEditor(
+                        text: $text,
+                        font: .systemFont(ofSize: settings.inputTextSize),
+                        textColor: NSColor(Color.oaiPrimary),
+                        isFocused: isInputFocused,
+                        onReturn: {
                             if showCommandDropdown {
                                 let suggestions = CommandSuggestionsView.filteredCommands(for: text)
                                 if !suggestions.isEmpty && selectedSuggestionIndex < suggestions.count {
                                     selectCommand(suggestions[selectedSuggestionIndex].command)
-                                    return .handled
+                                    return true
                                 }
                             }
-                            if !text.isEmpty { onSend(); return .handled }
-                            return .handled
+                            if !text.isEmpty { onSend(); return true }
+                            return true
+                        },
+                        onEscape: {
+                            if showCommandDropdown { showCommandDropdown = false; return true }
+                            if isGenerating { onCancel(); return true }
+                            return false
+                        },
+                        onUpArrow: {
+                            if showCommandDropdown && selectedSuggestionIndex > 0 {
+                                selectedSuggestionIndex -= 1; return true
                             }
-                        #endif
+                            return false
+                        },
+                        onDownArrow: {
+                            if showCommandDropdown {
+                                let count = CommandSuggestionsView.filteredCommands(for: text).count
+                                if selectedSuggestionIndex < count - 1 {
+                                    selectedSuggestionIndex += 1; return true
+                                }
+                            }
+                            return false
+                        },
+                        onFocusChange: { focused in isInputFocused = focused }
+                    )
+                    .frame(maxWidth: .infinity, maxHeight: .infinity)
+                    .onChange(of: text) {
+                        showCommandDropdown = text.hasPrefix("/")
+                        selectedSuggestionIndex = 0
+                    }
+                    .padding(.bottom, 30)
 
                     // Online / offline toggle — bottom-left of the text box
                     VStack {

oAI/Views/Main/NativeTextEditor.swift

@@ -0,0 +1,171 @@
+//
+//  NativeTextEditor.swift
+//  oAI
+//
+//  NSViewRepresentable text editor with correct Enter-key semantics:
+//  plain Enter → send, Shift+Enter or Cmd+Enter → newline.
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Copyright (C) 2026 Rune Olsen
+
+import SwiftUI
+import AppKit
+
+struct NativeTextEditor: NSViewRepresentable {
+    @Binding var text: String
+    var font: NSFont
+    var textColor: NSColor
+    var isFocused: Bool
+
+    /// Plain Enter (no modifiers). Return true if the event was consumed.
+    var onReturn: () -> Bool
+    /// Escape key. Return true if consumed.
+    var onEscape: () -> Bool
+    /// Up arrow. Return true if consumed.
+    var onUpArrow: () -> Bool
+    /// Down arrow. Return true if consumed.
+    var onDownArrow: () -> Bool
+    /// Called when the view gains or loses first-responder status.
+    var onFocusChange: (Bool) -> Void
+
+    // MARK: - NSViewRepresentable
+
+    func makeNSView(context: Context) -> NSScrollView {
+        let scrollView = NSScrollView()
+        scrollView.hasVerticalScroller = false
+        scrollView.hasHorizontalScroller = false
+        scrollView.drawsBackground = false
+        scrollView.borderType = .noBorder
+
+        let tv = context.coordinator.textView
+        tv.delegate = context.coordinator
+        tv.isEditable = true
+        tv.isRichText = false
+        tv.drawsBackground = false
+        tv.backgroundColor = .clear
+        tv.isAutomaticQuoteSubstitutionEnabled = false
+        tv.isAutomaticDashSubstitutionEnabled = false
+        tv.isAutomaticSpellingCorrectionEnabled = true
+        tv.isContinuousSpellCheckingEnabled = true
+        tv.allowsUndo = true
+        tv.isVerticallyResizable = true
+        tv.isHorizontallyResizable = false
+        tv.autoresizingMask = [.width]
+        tv.textContainer?.widthTracksTextView = true
+        tv.textContainerInset = NSSize(width: 8, height: 6)
+
+        scrollView.documentView = tv
+        return scrollView
+    }
+
+    func updateNSView(_ scrollView: NSScrollView, context: Context) {
+        let tv = context.coordinator.textView
+        let coord = context.coordinator
+
+        // Update text only when it differs (avoids caret-jumping on every keystroke)
+        if tv.string != text {
+            let sel = tv.selectedRanges
+            tv.string = text
+            let len = (tv.string as NSString).length
+            tv.selectedRanges = sel.map { v in
+                let r = v.rangeValue
+                let loc = min(r.location, len)
+                let length = min(r.length, max(0, len - loc))
+                return NSValue(range: NSRange(location: loc, length: length))
+            }
+        }
+
+        if tv.font != font       { tv.font = font }
+        if tv.textColor != textColor { tv.textColor = textColor }
+
+        // Keep coordinator callbacks current with each SwiftUI render
+        coord.textBinding  = $text
+        coord.onReturn     = onReturn
+        coord.onEscape     = onEscape
+        coord.onUpArrow    = onUpArrow
+        coord.onDownArrow  = onDownArrow
+        coord.onFocusChange = onFocusChange
+
+        if isFocused {
+            DispatchQueue.main.async {
+                guard let window = tv.window, window.firstResponder !== tv else { return }
+                window.makeFirstResponder(tv)
+            }
+        }
+    }
+
+    func makeCoordinator() -> Coordinator { Coordinator() }
+
+    // MARK: - Coordinator
+
+    final class Coordinator: NSObject, NSTextViewDelegate {
+        let textView = KeyableNSTextView()
+
+        // Updated on every SwiftUI render via updateNSView
+        var textBinding:   Binding<String>?
+        var onReturn:      () -> Bool = { false }
+        var onEscape:      () -> Bool = { false }
+        var onUpArrow:     () -> Bool = { false }
+        var onDownArrow:   () -> Bool = { false }
+        var onFocusChange: (Bool) -> Void = { _ in }
+
+        override init() {
+            super.init()
+            textView.coordinator = self
+        }
+
+        func textDidChange(_ notification: Notification) {
+            guard let tv = notification.object as? NSTextView else { return }
+            textBinding?.wrappedValue = tv.string
+        }
+    }
+}
+
+// MARK: - KeyableNSTextView
+
+/// NSTextView that routes Return / Escape / arrow keys to the SwiftUI
+/// coordinator before the AppKit default handling runs.
+final class KeyableNSTextView: NSTextView {
+    weak var coordinator: NativeTextEditor.Coordinator?
+
+    override func keyDown(with event: NSEvent) {
+        guard let coord = coordinator else { super.keyDown(with: event); return }
+
+        let flags = event.modifierFlags.intersection(.deviceIndependentFlagsMask)
+        let shift = flags.contains(.shift)
+        let cmd   = flags.contains(.command)
+
+        switch event.keyCode {
+        case 36: // Return
+            if shift || cmd {
+                // Shift+Enter or Cmd+Enter → literal newline
+                insertNewlineIgnoringFieldEditor(nil)
+            } else {
+                // Plain Enter → let SwiftUI decide (send or select dropdown item)
+                if !coord.onReturn() {
+                    insertNewlineIgnoringFieldEditor(nil)
+                }
+            }
+        case 53: // Escape
+            if !coord.onEscape() { super.keyDown(with: event) }
+        case 126: // Up arrow
+            if !coord.onUpArrow() { super.keyDown(with: event) }
+        case 125: // Down arrow
+            if !coord.onDownArrow() { super.keyDown(with: event) }
+        default:
+            super.keyDown(with: event)
+        }
+    }
+
+    override func becomeFirstResponder() -> Bool {
+        let ok = super.becomeFirstResponder()
+        if ok { coordinator?.onFocusChange(true) }
+        return ok
+    }
+
+    override func resignFirstResponder() -> Bool {
+        let ok = super.resignFirstResponder()
+        if ok { coordinator?.onFocusChange(false) }
+        return ok
+    }
+}

oAI/Views/Screens/CombineConversationsSheet.swift

@@ -0,0 +1,192 @@
+//
+//  CombineConversationsSheet.swift
+//  oAI
+//
+//  Combine 2+ saved conversations into one, optionally using AI to merge content
+//
+// 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 SwiftUI
+
+struct CombineConversationsSheet: View {
+    @Environment(\.dismiss) var dismiss
+
+    let conversations: [Conversation]
+    var onCompleted: (Conversation) -> Void
+
+    @State private var name: String
+    @State private var mode: CombineMode = .simple
+    @State private var deleteOriginals = false
+    @State private var isProcessing = false
+    @State private var errorMessage: String?
+
+    private let settings = SettingsService.shared
+
+    init(conversations: [Conversation], onCompleted: @escaping (Conversation) -> Void) {
+        self.conversations = conversations
+        self.onCompleted = onCompleted
+        let joined = conversations.map(\.name).joined(separator: " + ")
+        _name = State(initialValue: String(joined.prefix(80)))
+    }
+
+    private var defaultModelLabel: String? {
+        guard let model = settings.defaultModel, !model.isEmpty else { return nil }
+        return "\(settings.defaultProvider.displayName) / \(model)"
+    }
+
+    private var isValid: Bool {
+        !name.trimmingCharacters(in: .whitespaces).isEmpty
+            && conversations.count >= 2
+            && (mode == .simple || defaultModelLabel != nil)
+    }
+
+    var body: some View {
+        VStack(spacing: 0) {
+            HStack {
+                Text("Combine Conversations")
+                    .font(.system(size: 18, weight: .bold))
+                Spacer()
+                Button { dismiss() } label: {
+                    Image(systemName: "xmark.circle.fill")
+                        .font(.title2).foregroundStyle(.secondary)
+                }
+                .buttonStyle(.plain)
+                .keyboardShortcut(.escape, modifiers: [])
+                .disabled(isProcessing)
+            }
+            .padding(.horizontal, 24).padding(.top, 20).padding(.bottom, 16)
+
+            Divider()
+
+            ScrollView {
+                VStack(alignment: .leading, spacing: 16) {
+                    VStack(alignment: .leading, spacing: 6) {
+                        Text("Combining \(conversations.count) conversations").font(.system(size: 13, weight: .semibold))
+                        VStack(alignment: .leading, spacing: 4) {
+                            ForEach(conversations) { conversation in
+                                Label("\(conversation.name) (\(conversation.messageCount) messages)", systemImage: "bubble.left.and.bubble.right")
+                                    .font(.system(size: 12))
+                                    .foregroundStyle(.secondary)
+                            }
+                        }
+                    }
+
+                    VStack(alignment: .leading, spacing: 6) {
+                        Text("New conversation name").font(.system(size: 13, weight: .semibold))
+                        TextField("Name", text: $name)
+                            .textFieldStyle(.roundedBorder)
+                            .disabled(isProcessing)
+                    }
+
+                    VStack(alignment: .leading, spacing: 8) {
+                        Text("Merge method").font(.system(size: 13, weight: .semibold))
+                        Picker("", selection: $mode) {
+                            Text("Simple Merge").tag(CombineMode.simple)
+                            Text("AI-Assisted Merge").tag(CombineMode.ai)
+                        }
+                        .pickerStyle(.segmented)
+                        .labelsHidden()
+                        .disabled(isProcessing)
+
+                        if mode == .simple {
+                            Text("Messages from all selected conversations are combined in chronological order.")
+                                .font(.caption).foregroundStyle(.secondary)
+                        } else {
+                            Text("A model reads all the source messages and rewrites them into one coherent, de-duplicated conversation.")
+                                .font(.caption).foregroundStyle(.secondary)
+                            if let label = defaultModelLabel {
+                                Label("Uses your default model: \(label)", systemImage: "cpu")
+                                    .font(.caption).foregroundStyle(.secondary)
+                            } else {
+                                Label("No default model configured — set one in Settings → General.", systemImage: "exclamationmark.triangle.fill")
+                                    .font(.caption).foregroundStyle(.orange)
+                            }
+                        }
+                    }
+
+                    Toggle("Delete original conversations after combining", isOn: $deleteOriginals)
+                        .toggleStyle(.checkbox)
+                        .disabled(isProcessing)
+
+                    if let errorMessage {
+                        HStack(alignment: .top, spacing: 8) {
+                            Image(systemName: "xmark.octagon.fill").foregroundStyle(.red)
+                            Text(errorMessage).font(.caption)
+                        }
+                        .padding(10)
+                        .background(.red.opacity(0.08), in: RoundedRectangle(cornerRadius: 8))
+                    }
+                }
+                .padding(.horizontal, 24).padding(.vertical, 16)
+            }
+
+            Divider()
+
+            HStack {
+                Button("Cancel") { dismiss() }
+                    .buttonStyle(.bordered)
+                    .disabled(isProcessing)
+                Spacer()
+                if isProcessing {
+                    ProgressView().controlSize(.small)
+                    Text("Combining…").font(.caption).foregroundStyle(.secondary)
+                }
+                Button("Combine") {
+                    combine()
+                }
+                .buttonStyle(.borderedProminent)
+                .disabled(!isValid || isProcessing)
+                .keyboardShortcut(.return, modifiers: [.command])
+            }
+            .padding(.horizontal, 24).padding(.vertical, 12)
+        }
+        .frame(minWidth: 520, idealWidth: 560, minHeight: 460, idealHeight: 520)
+    }
+
+    private func combine() {
+        isProcessing = true
+        errorMessage = nil
+        let ids = conversations.map(\.id)
+        let trimmedName = name.trimmingCharacters(in: .whitespaces)
+        let selectedMode = mode
+        let shouldDeleteOriginals = deleteOriginals
+
+        Task {
+            do {
+                let newConversation = try await ConversationMergeService.merge(
+                    conversationIds: ids,
+                    name: trimmedName,
+                    mode: selectedMode,
+                    deleteOriginals: shouldDeleteOriginals
+                )
+                await MainActor.run {
+                    isProcessing = false
+                    onCompleted(newConversation)
+                    dismiss()
+                }
+            } catch {
+                await MainActor.run {
+                    isProcessing = false
+                    errorMessage = error.localizedDescription
+                }
+            }
+        }
+    }
+}

oAI/Views/Screens/ConversationListView.swift

@@ -36,6 +36,7 @@ struct ConversationListView: View {
     @State private var semanticResults: [Conversation] = []
     @State private var isSearching = false
     @State private var selectedIndex: Int = 0
+    @State private var showCombineSheet = false
     @FocusState private var searchFocused: Bool
     private let settings = SettingsService.shared
     var onLoad: ((Conversation) -> Void)?
@@ -70,6 +71,18 @@ struct ConversationListView: View {
                     }
                     .buttonStyle(.plain)
 
+                    if selectedConversations.count >= 2 {
+                        Button {
+                            showCombineSheet = true
+                        } label: {
+                            HStack(spacing: 4) {
+                                Image(systemName: "arrow.triangle.merge")
+                                Text("Combine (\(selectedConversations.count))")
+                            }
+                        }
+                        .buttonStyle(.plain)
+                    }
+
                     if !selectedConversations.isEmpty {
                         Button(role: .destructive) {
                             deleteSelected()
@@ -298,6 +311,16 @@ struct ConversationListView: View {
             searchFocused = true
         }
         .frame(minWidth: 700, idealWidth: 800, minHeight: 500, idealHeight: 600)
+        .sheet(isPresented: $showCombineSheet) {
+            CombineConversationsSheet(
+                conversations: conversations.filter { selectedConversations.contains($0.id) },
+                onCompleted: { _ in
+                    loadConversations()
+                    selectedConversations.removeAll()
+                    isSelecting = false
+                }
+            )
+        }
     }
 
     private func loadConversations() {

oAI/Views/Screens/CreditsView.swift

@@ -80,17 +80,6 @@ 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/ModelInfoView.swift

@@ -30,6 +30,7 @@ struct ModelInfoView: View {
 
     @Environment(\.dismiss) var dismiss
     @Bindable private var settings = SettingsService.shared
+    @State private var isDescriptionExpanded = false
 
     var body: some View {
         VStack(spacing: 0) {
@@ -78,8 +79,18 @@ struct ModelInfoView: View {
                             Text(desc)
                                 .font(.body)
                                 .foregroundColor(.primary)
-                                .fixedSize(horizontal: false, vertical: true)
+                                .lineLimit(isDescriptionExpanded ? nil : 4)
                                 .textSelection(.enabled)
+                            if desc.count > 250 {
+                                Button(isDescriptionExpanded ? "Less" : "More…") {
+                                    withAnimation(.easeInOut(duration: 0.2)) {
+                                        isDescriptionExpanded.toggle()
+                                    }
+                                }
+                                .font(.callout)
+                                .foregroundStyle(.blue)
+                                .buttonStyle(.plain)
+                            }
                         }
                         .padding(.leading, 4)
                     }

oAI/Views/Screens/SettingsView.swift

@@ -25,7 +25,6 @@
 
 import SwiftUI
 import UniformTypeIdentifiers
-import FoundationModels
 
 struct SettingsView: View {
     @Environment(\.dismiss) var dismiss
@@ -307,29 +306,6 @@ 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")
@@ -2673,28 +2649,6 @@ 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 {