Add native LLM core foundation (#24712)

packages/llm/src/provider.ts

@@ -0,0 +1,31 @@
+import type { RouteModelInput } from "./route/client"
+import type { ModelID, ModelRef, ProviderID } from "./schema"
+
+export type ModelOptions = Omit<RouteModelInput, "id">
+
+export type ModelFactory<Options extends ModelOptions = ModelOptions> = (
+  id: string | ModelID,
+  options?: Options,
+) => ModelRef
+
+type AnyModelFactory = (...args: never[]) => ModelRef
+
+export interface Definition<Factory extends AnyModelFactory = ModelFactory> {
+  readonly id: ProviderID
+  readonly model: Factory
+  readonly apis?: Record<string, AnyModelFactory>
+}
+
+type DefinitionShape = {
+  readonly id: ProviderID
+  readonly model: (...args: never[]) => ModelRef
+  readonly apis?: Record<string, (...args: never[]) => ModelRef>
+}
+
+type NoExtraFields<Input, Shape> = Input & Record<Exclude<keyof Input, keyof Shape>, never>
+
+export const make = <DefinitionType extends DefinitionShape>(
+  definition: NoExtraFields<DefinitionType, DefinitionShape>,
+) => definition
+
+export * as Provider from "./provider"