import { Context, Effect, Layer, Option } from "effect";
import { Prompt, Response, Tool } from "effect/unstable/ai";
import { AgentError } from "../agent/agent-event.js";
/** @experimental Typed operation-level adapter for LanguageModel.Service wrappers. */
export { adapt } from "./model-service.js";
/** @experimental Turn-scoped info handed to middleware. */
export interface TurnContext {
    readonly agentName: string;
    readonly turn: number;
}
/** @experimental A single middleware. Both hooks are optional; omitted hooks are identity. */
export interface Middleware {
    /** Transform the prompt for a turn before it is sent to the model. Recalled-memory messages must preserve lineage. */
    readonly transformPrompt?: (prompt: Prompt.Prompt, context: TurnContext) => Effect.Effect<Prompt.Prompt, AgentError>;
    /**
     * Transform or drop a model stream part before the loop processes it.
     * Return `Option.none()` to drop the part (it is not folded, not emitted, not persisted).
     * Tool-call parts may be transformed but MUST NOT be dropped — dropping a tool-call
     * is a middleware bug; the loop fails the run with MiddlewareViolation if it happens.
     */
    readonly transformPart?: (part: Response.StreamPart<Record<string, Tool.Any>>, context: TurnContext) => Effect.Effect<Option.Option<Response.StreamPart<Record<string, Tool.Any>>>, AgentError>;
}
declare const ModelMiddleware_base: Context.ServiceClass<ModelMiddleware, "@batonfx/core/model/model-middleware/ModelMiddleware", readonly Middleware[]>;
/** @experimental Service holding the middleware chain, applied in array order. */
export declare class ModelMiddleware extends ModelMiddleware_base {
}
/** @experimental Identity chain — the default. */
export declare const layerIdentity: Layer.Layer<ModelMiddleware>;
/** @experimental Provide an explicit chain. */
export declare const layer: (middleware: ReadonlyArray<Middleware>) => Layer.Layer<ModelMiddleware>;