# init(instructions:evaluationTarget:reference:) Creates a model prompt configuration. ``` init(instructions: String = ModelJudgePrompt.defaultInstructions, evaluationTarget: (@Sendable (Input.ExpectedValue) -> String)? = nil, reference: (nonisolated(nonsending) @Sendable (Input, Input.ExpectedValue) async throws -> [String : String])? = nil) ``` ## Parameters `instructions` System instructions for the model judge. Defaults to a general-purpose evaluator prompt. `evaluationTarget` Optional closure to convert the response to a string. When `nil`, the response is JSON-serialized. `reference` Optional closure returning labeled reference data to include in the model prompt. ## Discussion ```swift let prompt = ModelJudgePrompt>( instructions: "You are a domain expert." ) ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)