/**
 * Chat completion and embedding functions using the OpenAI API.
 *
 * Extracted from openai.ts to keep that module focused on
 * voice / vision services while this module handles text-level
 * AI calls (chat completions, embeddings, cosine similarity).
 */
export interface ChatMessage {
    role: "system" | "user" | "assistant";
    content: string;
}
/**
 * Lightweight chat completion using GPT-4o-mini.
 * Used for context preprocessing, not for agent dialogue.
 * Returns the assistant's text response.
 * Retries on 429/5xx with exponential backoff (up to 3 attempts).
 */
export declare function chatCompletion(messages: ChatMessage[], apiKey: string, options?: {
    maxTokens?: number;
    temperature?: number;
    timeoutMs?: number;
    model?: string;
    responseFormat?: {
        type: string;
    };
    /** Usage-meter bucket for this call (defaults to "chat"). */
    category?: string;
    /** Originating thread, for usage attribution. */
    threadId?: number;
}): Promise<string>;
/**
 * Generate an embedding vector for text using OpenAI's text-embedding-3-small model.
 * Returns a Float32Array of 1536 dimensions.
 *
 * @param threadId Originating thread, when known — used for usage attribution only.
 */
export declare function generateEmbedding(text: string, apiKey: string, threadId?: number): Promise<Float32Array>;
/** Compute cosine similarity between two embedding vectors. Returns value in [-1, 1]. */
export declare function cosineSimilarity(a: Float32Array, b: Float32Array): number;
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