import type { ExtensionContext } from "@oh-my-pi/pi-coding-agent";
/**
 * Host compatibility layer for pi vs omp (oh-my-pi) API differences.
 *
 * pi: systemPrompt is string, getSystemPrompt() returns string
 * omp: systemPrompt is string[], getSystemPrompt() returns string[]
 *
 * These helpers normalize the differences so the rest of the codebase
 * can work with a consistent string interface.
 */
/** Normalize systemPrompt to a single string (join with newlines if array). */
export declare function normalizeSystemPrompt(input: string | string[] | undefined): string;
/**
 * Format systemPrompt for the before_agent_start event handler.
 * omp's BeforeAgentStartEventResult.systemPrompt is string[]: each entry is a
 * prompt segment. We normalize the incoming base (string | string[]) to one
 * string, append the ACP block, and return it as a single-element array.
 */
export declare function formatSystemPromptForEvent(base: string | string[], append: string): string[];
/**
 * Get the system prompt as a single string, regardless of host type.
 * Handles both pi (string) and omp (string[]) return types.
 */
export declare function getSystemPromptText(ctx: ExtensionContext): string;