/**
 * Defensive “gas eats profit” floor for Base micropayments.
 *
 * When L2 gas spikes, $0.001–$0.01 charges can become uneconomic. With
 * `X402_DYNAMIC_MIN_ENABLED=true`, we estimate settle gas in USD from a
 * cached base-fee oracle and bump the minimum accept amount (and optionally
 * raise feeFreeBelow so FeeSplitter+release isn’t used until larger amounts).
 *
 * Default OFF — demo `$0.001` still works under normal Base fees.
 */
/** Subset of TollgateConfig needed by the gas floor (avoids circular imports). */
export interface GasFloorConfig {
    price: string;
    feeBps: number;
    feeFreeBelowUsdc: bigint;
    minPriceUsdc: bigint;
    dynamicMinEnabled: boolean;
    gasCostMaxFraction: number;
    gasOracleRpcUrl: string;
    gasOracleTtlMs: number;
    gasUsedEstimate: number;
    ethUsd: number;
}
/** Default gas units for a rough L2 EIP-3009 / ERC-20 settle estimate. */
export declare const DEFAULT_GAS_USED_ESTIMATE = 100000;
/** Conservative ETH/USD floor when no live price feed (higher → more protective). */
export declare const DEFAULT_ETH_USD = 4000;
/** Max fraction of payment that estimated gas may consume before bumping (50%). */
export declare const DEFAULT_GAS_COST_MAX_FRACTION = 0.5;
/** Base-fee cache TTL (ms). Clamped to 15–60s. */
export declare const DEFAULT_GAS_ORACLE_TTL_MS = 30000;
export declare const MIN_GAS_ORACLE_TTL_MS = 15000;
export declare const MAX_GAS_ORACLE_TTL_MS = 60000;
export type GasFloorReason = "disabled" | "static" | "min_floor" | "gas";
export interface GasFloorSnapshot {
    enabled: boolean;
    /** Configured PRICE as atomic USDC. */
    configuredPriceAtomic: bigint;
    /** Static X402_MIN_PRICE_USDC (0 when unset). */
    minPriceUsdc: bigint;
    /** Configured fee-free threshold. */
    configuredFeeFreeBelowUsdc: bigint;
    /** Enforced / displayed minimum accept amount (atomic USDC). */
    effectiveMinPriceAtomic: bigint;
    /** Effective fee-free threshold after optional gas-aware raise. */
    effectiveFeeFreeBelowUsdc: bigint;
    /** Dollar form of effective min (e.g. `$0.001`). */
    effectiveMinPrice: string;
    /** Last observed / injected base fee (wei), or null. */
    baseFeeWei: string | null;
    /** Estimated L2 gas cost in USD, or null when unknown / disabled. */
    estimatedGasCostUsd: number | null;
    gasCostMaxFraction: number;
    ethUsd: number;
    gasUsedEstimate: number;
    bumped: boolean;
    reason: GasFloorReason;
    oracleTtlMs: number;
    cachedAt: number | null;
}
export interface ComputeEffectiveMinsInput {
    priceAtomic: bigint;
    minPriceUsdc: bigint;
    feeFreeBelowUsdc: bigint;
    dynamicMinEnabled: boolean;
    /** null → skip gas bump (static floors only). */
    gasCostUsd: number | null;
    gasCostMaxFraction: number;
    /** Operator fee bps — used to raise feeFreeBelow so 0.1% can cover release gas. */
    feeBps: number;
    usdcDecimals?: number;
}
/**
 * Pure floor math (unit-testable with mocked gas USD).
 *
 * - effectiveMin = max(price, minPriceUsdc, gasDerivedMin when enabled)
 * - gasDerivedMin = ceil(gasCostUsd / maxFraction) in atomic USDC
 * - When gas forces a bump, also raise feeFreeBelow so FeeSplitter+release
 *   is deferred until amounts where feeBps can cover estimated gas.
 */
export declare function computeEffectiveMins(input: ComputeEffectiveMinsInput): {
    effectiveMinPriceAtomic: bigint;
    effectiveFeeFreeBelowUsdc: bigint;
    bumped: boolean;
    reason: GasFloorReason;
    gasDerivedMinAtomic: bigint | null;
};
/** gasUsed * baseFeeWei * ethUsd / 1e18 */
export declare function estimateGasCostUsd(baseFeeWei: bigint, gasUsedEstimate: number, ethUsd: number): number;
export declare function usdToAtomicUsdc(usd: number, decimals?: number): bigint;
export declare function dollarPriceToAtomic(price: string, decimals?: number): bigint;
export declare function atomicUsdcToDollarPrice(atomic: bigint, decimals?: number): string;
export type BaseFeeFetcher = () => Promise<bigint>;
export interface GasFloorOracleOptions {
    rpcUrl: string;
    ttlMs: number;
    /** Inject for tests. */
    fetchBaseFee?: BaseFeeFetcher;
    /** Inject clock for tests. */
    now?: () => number;
    fetchImpl?: typeof fetch;
}
/** Cached eth_getBlockByNumber baseFeePerGas reader (TTL 15–60s). */
export declare function createBaseFeeOracle(options: GasFloorOracleOptions): {
    getBaseFeeWei: () => Promise<bigint>;
    peekCache: () => {
        baseFeeWei: bigint;
        fetchedAt: number;
    } | null;
    clearCache: () => void;
};
export declare function clampTtl(ms: number): number;
export declare function defaultRpcUrlForNetwork(network: string): string;
export interface GasFloorService {
    getSnapshot: () => Promise<GasFloorSnapshot>;
    /** Sync view using last cached base fee (no RPC). Safe for middleware rewrites. */
    getSnapshotSync: () => GasFloorSnapshot;
    /** Refresh cache (no-op when dynamic disabled). */
    refresh: () => Promise<void>;
    clearCache: () => void;
}
export declare function createGasFloorService(config: GasFloorConfig, options?: {
    fetchBaseFee?: BaseFeeFetcher;
    now?: () => number;
    fetchImpl?: typeof fetch;
}): GasFloorService;