Feature/structured streamable output (#7)

* Add streamed structured output and split messaging internals

* Refactor structured stream parser loop

Author: timazed

DemoApp/AssistantRuntimeDemoApp/Shared/AgentDemoViewModel+StructuredOutput.swift

@@ -99,4 +99,98 @@ extension AgentDemoViewModel {
             lastError = error.localizedDescription
         }
     }
+
+    func runStreamedStructuredOutputDemo() async {
+        guard session != nil else {
+            lastError = "Sign in before running the streamed structured output demo."
+            return
+        }
+        guard !isRunningStructuredStreamingDemo else {
+            return
+        }
+
+        isRunningStructuredStreamingDemo = true
+        lastError = nil
+        structuredStreamingResult = nil
+        structuredStreamingError = nil
+        defer {
+            isRunningStructuredStreamingDemo = false
+        }
+
+        do {
+            let thread = try await runtime.createThread(
+                title: "Structured Output: Streamed Delivery Update",
+                personaStack: Self.supportPersona
+            )
+            let request = DemoStructuredOutputExamples.streamedStructuredRequest()
+            if showResolvedInstructionsDebug {
+                lastResolvedInstructions = try await runtime.resolvedInstructionsPreview(
+                    for: thread.id,
+                    request: request
+                )
+                lastResolvedInstructionsThreadTitle = thread.title ?? "Structured Output: Streamed Delivery Update"
+            }
+
+            let stream = try await runtime.streamMessage(
+                request,
+                in: thread.id,
+                expecting: StreamedStructuredDeliveryUpdate.self
+            )
+
+            var visibleText = ""
+            var partialSnapshots: [StreamedStructuredDeliveryUpdate] = []
+            var committedPayload: StreamedStructuredDeliveryUpdate?
+
+            for try await event in stream {
+                switch event {
+                case let .assistantMessageDelta(_, _, delta):
+                    visibleText += delta
+
+                case let .messageCommitted(message):
+                    if message.role == .assistant {
+                        visibleText = message.displayText
+                    }
+
+                case let .structuredOutputPartial(partial):
+                    if partialSnapshots.last != partial {
+                        partialSnapshots.append(partial)
+                    }
+
+                case let .structuredOutputCommitted(payload):
+                    committedPayload = payload
+
+                case let .turnFailed(error):
+                    throw error
+
+                default:
+                    break
+                }
+            }
+
+            let messages = await runtime.messages(for: thread.id)
+            let persistedMetadata = messages.last(where: { $0.role == .assistant })?.structuredOutput
+
+            guard let committedPayload else {
+                throw AgentRuntimeError.structuredOutputMissing(
+                    formatName: StreamedStructuredDeliveryUpdate.responseFormat.name
+                )
+            }
+
+            structuredStreamingResult = StructuredStreamingDemoResult(
+                threadID: thread.id,
+                threadTitle: thread.title ?? "Structured Output: Streamed Delivery Update",
+                prompt: DemoStructuredOutputExamples.streamedStructuredPrompt,
+                visibleText: visibleText.trimmingCharacters(in: .whitespacesAndNewlines),
+                partialSnapshots: partialSnapshots,
+                committedPayload: committedPayload,
+                persistedMetadata: persistedMetadata
+            )
+            threads = await runtime.threads()
+            activeThreadID = thread.id
+            setMessages(messages)
+        } catch {
+            structuredStreamingError = error.localizedDescription
+            lastError = error.localizedDescription
+        }
+    }
 }

DemoApp/AssistantRuntimeDemoApp/Shared/AgentDemoViewModel.swift

@@ -39,6 +39,16 @@ struct StructuredOutputDemoImportResult: Sendable {
     let summary: StructuredImportedContentSummary
 }
 
+struct StructuredStreamingDemoResult: Sendable {
+    let threadID: String
+    let threadTitle: String
+    let prompt: String
+    let visibleText: String
+    let partialSnapshots: [StreamedStructuredDeliveryUpdate]
+    let committedPayload: StreamedStructuredDeliveryUpdate
+    let persistedMetadata: AgentStructuredOutputMetadata?
+}
+
 struct GuidedMemoryDemoResult: Sendable {
     let record: MemoryRecord
     let diagnostics: MemoryStoreDiagnostics
@@ -135,8 +145,11 @@ final class AgentDemoViewModel: @unchecked Sendable {
     var pendingComposerImages: [AgentImageAttachment] = []
     var composerText = ""
     var isRunningStructuredOutputDemo = false
+    var isRunningStructuredStreamingDemo = false
     var structuredShippingReplyResult: StructuredOutputDemoDraftResult?
     var structuredImportedSummaryResult: StructuredOutputDemoImportResult?
+    var structuredStreamingResult: StructuredStreamingDemoResult?
+    var structuredStreamingError: String?
     var isRunningMemoryDemo = false
     var automaticMemoryResult: AutomaticMemoryDemoResult?
     var automaticPolicyMemoryResult: AutomaticPolicyMemoryDemoResult?

DemoApp/AssistantRuntimeDemoApp/Shared/DemoStructuredOutputExamples.swift

@@ -47,6 +47,26 @@ struct StructuredImportedContentSummary: AgentStructuredOutput, Sendable {
     )
 }
 
+struct StreamedStructuredDeliveryUpdate: AgentStructuredOutput, Sendable, Hashable {
+    let statusHeadline: String
+    let customerPromise: String
+    let nextAction: String
+
+    static let responseFormat = AgentStructuredOutputFormat(
+        name: "streamed_delivery_update",
+        description: "A structured operational delivery update produced alongside visible assistant narration.",
+        schema: .object(
+            properties: [
+                "statusHeadline": .string(),
+                "customerPromise": .string(),
+                "nextAction": .string(),
+            ],
+            required: ["statusHeadline", "customerPromise", "nextAction"],
+            additionalProperties: false
+        )
+    )
+}
+
 enum DemoStructuredOutputExamples {
     static let shippingCustomerMessage = """
     My package was supposed to arrive yesterday for a birthday on Saturday. Tracking has not moved in two days and I need to know whether it will make it in time.
@@ -57,6 +77,9 @@ enum DemoStructuredOutputExamples {
     """
 
     static let importedArticleURL = URL(string: "https://github.com/timazed/CodexKit")!
+    static let streamedStructuredPrompt = """
+    The package is delayed ahead of a birthday delivery. Talk to the customer like an in-app support assistant while you work through the situation. Stream a short human-readable response only. Do not restate the final structured delivery fields in prose because the app receives those separately. Then provide the final typed delivery update for the app.
+    """
 
     static func shippingReplyRequest() -> UserMessageRequest {
         UserMessageRequest(
@@ -78,4 +101,8 @@ enum DemoStructuredOutputExamples {
             )
         )
     }
+
+    static func streamedStructuredRequest() -> UserMessageRequest {
+        UserMessageRequest(text: streamedStructuredPrompt)
+    }
 }