swift-format

Author: sebsto

Examples/converse-stream/Sources/ConverseStream.swift

@@ -0,0 +1,91 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Bedrock Library open source project
+//
+// Copyright (c) 2025 Amazon.com, Inc. or its affiliates
+//                    and the Swift Bedrock Library project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift Bedrock Library project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import BedrockService
+import Logging
+
+@main
+struct Main {
+    static func main() async throws {
+        do {
+            try await Main.converseStream()
+        } catch {
+            print("Error:\n\(error)")
+        }
+    }
+    static func converseStream() async throws {
+        var logger = Logger(label: "Converse")
+        logger.logLevel = .debug
+
+        let bedrock = try await BedrockService(
+            region: .useast1,
+            logger: logger
+                // uncomment if you use SSO with AWS Identity Center
+                // authentication: .sso
+        )
+
+        // select a model that supports the converse modality
+        // models must be enabled in your AWS account
+        let model: BedrockModel = .nova_lite
+
+        guard model.hasConverseModality() else {
+            throw MyError.incorrectModality("\(model.name) does not support converse")
+        }
+
+        // create a request
+        let builder = try ConverseRequestBuilder(with: model)
+            .withPrompt("Tell me about rainbows")
+
+        // send the request
+        let reply = try await bedrock.converseStream(with: builder)
+
+        // the reply gives access to two streams.
+        // 1. `stream` is a high-level stream that provides elements of the conversation :
+        // - messageStart: this is the start of a message, it contains the role (assistant or user)
+        // - text: this is a delta of the text content, it contains the partial text
+        // - reasoning: this is a delta of the reasoning content, it contains the partial reasoning text
+        // - toolUse: this is a buffered tool use response, it contains the tool name and id, and the input parameters
+        // - message complete: this includes the complete Message, ready to be added to the history and used for future requests
+        // - metaData: this is the metadata about the response, it contains statitics about the response, such as the number of tokens used and the latency
+        //
+        // 2. `sdkStream` is the low-level stream provided by the AWS SDK. Use it when you need low level access to the stream,
+        //    such as when you want to handle the stream in a custom way or when you need to access the raw data.
+        //    see : https://docs.aws.amazon.com/bedrock/latest/userguide/conversation-inference-call.html#conversation-inference-call-response-converse-stream
+        for try await element in reply.stream {
+            // process the stream elements
+            switch element {
+            case .messageStart(let role):
+                logger.info("Message started with role: \(role)")
+            case .text(_, let text):
+                print(text, terminator: "")
+            case .reasoning(let index, let reasoning):
+                logger.info("Reasoning delta: \(reasoning)", metadata: ["index": "\(index)"])
+            case .toolUse(let index, let toolUse):
+                logger.info(
+                    "Tool use: \(toolUse.name) with id: \(toolUse.id) and input: \(toolUse.input)",
+                    metadata: ["index": "\(index)"]
+                )
+            case .messageComplete(_):
+                print("\n")
+            case .metaData(let metaData):
+                logger.info("Metadata: \(metaData)")
+            }
+        }
+    }
+
+    enum MyError: Error {
+        case incorrectModality(String)
+    }
+}

Sources/Converse/Message.swift

@@ -132,7 +132,7 @@ public struct Message: Codable, CustomStringConvertible, Sendable {
             return nil
         }
     }
-    
+
     public func hasImageContent() -> Bool {
         content.contains { $0.isImage() }
     }