Genkit for Dart 0.15.1

Apply the Dart 3.13 prompt first. These rules cover genkit 0.15.1 on Dart 3.13; its SDK constraint is >=3.10.0 <4.0.0. Optional integration rules refer to genkit_shelf 0.1.11, genkit_middleware 0.5.1, genkit_mcp 0.2.3, and Schemantic 0.2.2 with its 0.1.2 builder. Keep their resolved versions compatible with this release; newer Genkit documentation can describe different APIs and safeguards.

Configuration, prompts, and model authority

• Construct Genkit, plugins, model references, config, middleware use, and tool selections from trusted application policy. Keep privileged orchestration and provider credentials on a trusted server when callers control the Dart or Flutter client.
• Set promptDir: null when automatic loading is unnecessary; otherwise point it at an immutable application directory. The default ./prompts loader recursively registers templates, partials, and variants, and .prompt frontmatter can select models, tools, middleware, toolChoice, maxTurns, and returnToolRequests.
• Keep definePrompt templates, helpers, system instructions, and PromptGenerateOptions overrides under application control. Supply user text as data; do not accept arbitrary messages, roles, tool-request parts, or template source as a public generation interface.
• Treat retrieved documents, DocumentData metadata, media, tool results, and remembered messages as untrusted content. Authorize documents before embedding or adding them to a model request, enforce tenant filters in the retrieval service, and never interpret retrieved instructions as