/**
 * Utility functions for mapping unified ToolChoice to provider-specific formats.
 */
import type { ToolChoice } from "../types";
/** OpenAI Completions API tool choice format */
export type OpenAICompletionsToolChoice = "auto" | "none" | "required" | {
    type: "function";
    function: {
        name: string;
    };
} | undefined;
/** OpenAI Responses API tool choice format (flat structure) */
export type OpenAIResponsesToolChoice = "auto" | "none" | "required" | {
    type: "function";
    name: string;
} | {
    type: "custom";
    name: string;
} | undefined;
/** Anthropic-compatible tool choice format */
export type AnthropicToolChoice = "auto" | "none" | "any" | {
    type: "tool";
    name: string;
} | undefined;
/**
 * Map unified ToolChoice to OpenAI Completions API format.
 * - "any" → "required"
 * - { type: "tool", name } → { type: "function", function: { name } }
 */
export declare function mapToOpenAICompletionsToolChoice(choice?: ToolChoice): OpenAICompletionsToolChoice;
/**
 * Returns true when an OpenAI-completions `tool_choice` value forces a tool
 * call (`"required"` or a function-name pin), as opposed to leaving it open
 * (`"auto"`, `"none"`, or unset). Accepts `unknown` because the param shape
 * pulled from the OpenAI SDK (`ChatCompletionToolChoiceOption`) widens with
 * each release; this check only needs the open/forced bit.
 */
export declare function isForcedToolChoice(choice: unknown): boolean;
/**
 * Map unified ToolChoice to OpenAI Responses API format.
 * - "any" → "required"
 * - { type: "tool", name } → { type: "function", name } (flat structure)
 */
export declare function mapToOpenAIResponsesToolChoice(choice?: ToolChoice): OpenAIResponsesToolChoice;
/**
 * Map unified ToolChoice to Anthropic-compatible format.
 * - "required" → "any"
 * - { type: "function", ... } → { type: "tool", name }
 */
export declare function mapToAnthropicToolChoice(choice?: ToolChoice): AnthropicToolChoice;