/**
 * Runtime OpenRouter model capability detection.
 *
 * When an OpenRouter model is not in the built-in static list, we look up its
 * actual capabilities from a cached copy of the OpenRouter model catalog.
 *
 * Cache layers (checked in order):
 * 1. In-memory Map (instant, cleared on process restart)
 * 2. On-disk JSON file (<stateDir>/cache/openrouter-models.json)
 * 3. OpenRouter API fetch (populates both layers)
 *
 * Model capabilities are assumed stable — the cache has no TTL expiry.
 * A background refresh is triggered only when a model is not found in
 * the cache (i.e. a newly added model on OpenRouter).
 *
 * Sync callers can read whatever is already cached. Async callers can await a
 * one-time fetch so the first unknown-model lookup resolves with real
 * capabilities instead of the text-only fallback.
 */
export interface OpenRouterModelCapabilities {
    name: string;
    input: Array<"text" | "image">;
    reasoning: boolean;
    contextWindow: number;
    maxTokens: number;
    cost: {
        input: number;
        output: number;
        cacheRead: number;
        cacheWrite: number;
    };
}
/**
 * Ensure the cache is populated. Checks in-memory first, then disk, then
 * triggers a background API fetch as a last resort.
 * Does not block — returns immediately.
 */
export declare function ensureOpenRouterModelCache(): void;
/**
 * Ensure capabilities for a specific model are available before first use.
 *
 * Known cached entries return immediately. Unknown entries wait for at most
 * one catalog fetch, then leave sync resolution to read from the populated
 * cache on the same request.
 */
export declare function loadOpenRouterModelCapabilities(modelId: string): Promise<void>;
/**
 * Synchronously look up model capabilities from the cache.
 *
 * If a model is not found but the cache exists, a background refresh is
 * triggered in case it's a newly added model not yet in the cache.
 */
export declare function getOpenRouterModelCapabilities(modelId: string): OpenRouterModelCapabilities | undefined;