/**
 * Fetch the latest USD price for a token symbol from CoinGecko's
 * `/market_chart/range` endpoint, mapped through `COINGECKO_COIN_ID_MAP`.
 *
 * @param symbol - Token symbol (case-insensitive). Must be present in
 *   `COINGECKO_COIN_ID_MAP`.
 * @param coinGeckoKey - CoinGecko Pro API key passed as `x-cg-pro-api-key`.
 * @returns The latest price in USD (a number) on success; `null` when the
 *   response contains an empty or missing `prices` array. `musd` (mezo-usd)
 *   is a USD-pegged stablecoin and short-circuits to a price of `1`.
 * @throws {@link AugustValidationError} When `symbol` is not in `COINGECKO_COIN_ID_MAP`.
 * @throws {@link AugustRateLimitError} On a 429 response from CoinGecko.
 * @throws {@link AugustServerError} On any other non-2xx response.
 */
export declare function fetchTokenPricesFromCoinGecko(symbol: string, coinGeckoKey: string): Promise<number>;