Swift: Added example code for text to image generation with Amazon Nova Canvas for Bedrock (#7452)

* Converse and ConverseStream code examples

Author: monadierickx

.doc_gen/metadata/bedrock-runtime_metadata.yaml

@@ -1321,6 +1321,14 @@ bedrock-runtime_InvokeModel_AmazonNovaImageGeneration:
             - description: Create an image with the Amazon Nova Canvas.
               snippet_tags:
                 - python.example_code.bedrock-runtime.InvokeModel_AmazonNovaImageGeneration
+    Swift:
+      versions:
+        - sdk_version: 1
+          github: swift/example_code/bedrock-runtime
+          excerpts:
+            - description: Create an image with Amazon Nova Canvas.
+              snippet_tags:
+                - swift.example_code.bedrock-runtime.InvokeModel_AmazonNovaImageGeneration
   services:
     bedrock-runtime: {InvokeModel}
 

swift/example_code/bedrock-runtime/README.md

@@ -36,6 +36,10 @@ For prerequisites, see the [README](../../README.md#Prerequisites) in the `swift
 - [Converse](models/amazon-nova/amazon-nova-text/Sources/Converse/main.swift#L4)
 - [ConverseStream](models/amazon-nova/amazon-nova-text/Sources/ConverseStream/main.swift#L4)
 
+### Amazon Nova Canvas
+
+- [InvokeModel](models/amazon-nova/amazon-nova-canvas/Sources/main.swift#L4)
+
 ### Amazon Nova Reel
 
 - [Text-to-video](models/amazon-nova/amazon-nova-reel/Sources/main.swift#L4)

swift/example_code/bedrock-runtime/models/amazon-nova/amazon-nova-canvas/Package.swift

@@ -0,0 +1,31 @@
+// swift-tools-version: 6.1
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+// 
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "AmazonNovaCanvas",
+    // Let Xcode know the minimum Apple platforms supported.
+    platforms: [
+        .macOS(.v13),
+        .iOS(.v15)
+    ],
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        .package(url: "https://github.com/awslabs/aws-sdk-swift", from: "1.2.61")
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package, defining a module or a test suite.
+        // Targets can depend on other targets in this package and products from dependencies.
+        .executableTarget(
+            name: "InvokeModel",
+            dependencies: [
+                .product(name: "AWSBedrockRuntime", package: "aws-sdk-swift"),
+            ],
+            path: "Sources"
+        )
+    ]
+)

swift/example_code/bedrock-runtime/models/amazon-nova/amazon-nova-canvas/Sources/main.swift

@@ -0,0 +1,76 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+//
+// snippet-start:[swift.example_code.bedrock-runtime.InvokeModel_AmazonNovaImageGeneration]
+// Use the native inference API to create an image with Amazon Nova Canvas
+
+import AWSBedrockRuntime
+import AWSSDKIdentity
+import Foundation
+
+struct NovaImageOutput: Decodable {
+    let images: [Data]
+}
+
+func generateImage(_ textPrompt: String) async throws {
+    // Create a Bedrock Runtime client in the AWS Region you want to use.
+    let config =
+        try await BedrockRuntimeClient.BedrockRuntimeClientConfiguration(
+            region: "us-east-1"
+        )
+    config.awsCredentialIdentityResolver = try SSOAWSCredentialIdentityResolver()
+
+    let client = BedrockRuntimeClient(config: config)
+
+    // Set the model ID.
+    let modelId = "amazon.nova-canvas-v1:0"
+
+    //  Format the request payload using the model's native structure.
+    let input = InvokeModelInput(
+        accept: "application/json",
+        body: """
+            {
+                "textToImageParams": {
+                    "text": "\(textPrompt)"
+                },
+                "taskType": "TEXT_IMAGE",
+                "imageGenerationConfig": {
+                    "seed": 42,
+                    "quality": "standard",
+                    "width": 512,
+                    "height": 512,
+                    "numberOfImages": 1
+                }
+            }
+            """.data(using: .utf8),
+        modelId: modelId
+    )
+
+    // Invoke the model with the request.
+    let response = try await client.invokeModel(input: input)
+
+    // Decode the response body.
+    let output = try JSONDecoder().decode(NovaImageOutput.self, from: response.body!)
+
+    // Extract the image data.
+    guard let data = output.images.first else {
+        print("No image data found")
+        return
+    }
+
+    // Save the generated image to a local folder.
+    let fileURL = URL.documentsDirectory.appending(path: "nova_canvas.png")
+    print(fileURL)
+    try data.write(to: fileURL)
+    print("Image is saved at \(fileURL)")
+}
+
+// snippet-end:[swift.example_code.bedrock-runtime.InvokeModel_AmazonNovaImageGeneration]
+
+do {
+    try await generateImage(
+        "A tabby cat in a teacup"
+    )
+} catch {
+    print("An error occurred: \(error)")
+}