Foundation Models: Please Allow GeneratedContent Init from Array of Key-Value Pairs

For anyone looking for a temporary solution, you can (but probably shouldn't) do this:

struct DynamicKeyValuePairs<K, V> {
    let _elements: [(K, V)]

    init(_elements: [(K, V)]) {
        self._elements = _elements
    }
}

let kvp = unsafeBitCast(
    DynamicKeyValuePairs(_elements: properties),
    to: KeyValuePairs<String, any ConvertibleToGeneratedContent>.self
)

To explain a little why this might be useful:

– It allows for more use cases of Foundation Models from non-native frameworks like Flutter and React Native.

Here is an example of how you can create a bridge from Flutter to Foundation Models, with Dart Tools support.

– It also opens up use cases like MCP servers, where tools are dynamically fetched from some config/server. Though not very usable given current model constraints — but still.

I am trying to do the same for React Native

Just found they added a new initializer from a JSON string somewhere between the second and third beta. It's even better than I expected

https://developer.apple.com/documentation/foundationmodels/generatedcontent/init(json:)