diff --git a/README.md b/README.md
index 7a5e6c9..3e2808a 100644
--- a/README.md
+++ b/README.md
@@ -51,7 +51,7 @@ const incompleteTx: TransactionData = {
 
 const feeOracle = new TornadoFeeOracleV5(1, 'https://eth.llamarpc.com');
 const transactionType: TxType = 'relayer_withdrawal';
-const gasPrice = await feeOracle.getGasPriceInHex(transactionType);
+const gasPrice = await feeOracle.getGasPrice(transactionType);
 const gasLimit = await feeOracle.getGasLimit(incompleteTx, transactionType);
 
 const tx: TransactionData = Object.assign({ gasPrice, gasLimit }, incompleteTx);
diff --git a/package.json b/package.json
index 29acfe1..fafec3c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tornado/tornado-oracles",
-  "version": "0.3.0",
+  "version": "1.0.0",
   "description": "Gas oracle for Tornado-specific transactions",
   "main": "./lib/index.js",
   "types": "./lib/index.d.ts",
diff --git a/src/feeOracle.ts b/src/feeOracle.ts
index 190a939..8dde27b 100644
--- a/src/feeOracle.ts
+++ b/src/feeOracle.ts
@@ -1,7 +1,7 @@
 import { GasPriceOracle } from '@tornado/gas-price-oracle';
 import { BigNumber, BigNumberish, ethers } from 'ethers';
 import { parseUnits } from 'ethers/lib/utils';
-import { TransactionData, TxType, ITornadoFeeOracle, GasPrice, LegacyGasPriceKey } from './types';
+import { TransactionData, TxType, ITornadoFeeOracle, LegacyGasPriceKey, GasPriceParams } from './types';
 import { JsonRpcProvider } from '@ethersproject/providers';
 import { ChainId, defaultGasPrices } from './config';
 import { bump, calculateGasPriceInWei, convertETHToToken, fromGweiToWeiHex, serializeTx } from './utils';
@@ -36,23 +36,23 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
   /**
    * Estimates next block gas for signed, unsigned or incomplete Tornado transaction
    * @param {TransactionData} tx Transaction data in web3 / ethers format
-   * @param {TxType} type Tornado transaction type: withdrawal by user, withdrawal by relayer or 'other'
+   * @param {TxType} txType Tornado transaction type: withdrawal by user, withdrawal by relayer or 'other'
    * @param {LegacyGasPriceKey} speed Preferred transaction speed, if uses legacy gas (before EIP-1559)
    * @returns {Promise<string>} Gas value in WEI (hex-format)
    */
   public async getGas(
     tx?: TransactionData,
-    type: TxType = 'other',
+    txType: TxType = 'other',
     speed: LegacyGasPriceKey = 'fast',
-  ): Promise<BigNumber> {
-    const gasPrice = await this.getGasPriceInHex(type, speed);
+  ): Promise<string> {
+    const gasPrice = await this.getGasPrice(txType, speed);
     let gas = BigNumber.from(0);
     gas = gas.add(gasPrice);
     if (tx) tx = Object.assign(tx, { gasPrice });
-    gas = gas.mul(await this.getGasLimit(tx, type));
+    gas = gas.mul(await this.getGasLimit(tx, txType));
     if (this.chainId === ChainId.OPTIMISM) gas = gas.add(await this.fetchL1OptimismFee(tx));
 
-    return gas;
+    return gas.toHexString();
   }
 
   /**
@@ -60,18 +60,18 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
    * @param {TxType} type Tornado transaction type (to select correct default bump percent)
    * @param {LegacyGasPriceKey} speed Preferred transaction speed, if uses legacy gas (before EIP-1559)
    * @param {number} bumpPercent Gas bump percent to prioritize transaction
-   * @returns {Promise<GasPrice>} Estimated gas price info in WEI (hexed) - legacy object with gasPrice property or EIP-1559 object with maxFeePerGas
-   *  and maxPriorityFeePerGas properties
+   * @returns {Promise<GasPriceParams>} Estimated gas price info in WEI (hexed) - legacy object with gasPrice property or
+   * EIP-1559 object with maxFeePerGas and maxPriorityFeePerGas properties
    */
-  async getGasPrice(
+  async getGasPriceParams(
     type: TxType = 'other',
     speed: LegacyGasPriceKey = 'fast',
     bumpPercent: number = 0,
-  ): Promise<GasPrice> {
+  ): Promise<GasPriceParams> {
     try {
       return await this.oracle.getTxGasParams({ legacySpeed: speed, bumpPercent });
     } catch (e) {
-      return { gasPrice: bump(fromGweiToWeiHex(defaultGasPrices[this.chainId][speed]), bumpPercent) };
+      return { gasPrice: bump(fromGweiToWeiHex(defaultGasPrices[this.chainId][speed]), bumpPercent).toHexString() };
     }
   }
 
@@ -82,22 +82,22 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
    * @param {number} bumpPercent Gas bump percent to prioritize transaction
    * @returns {Promise<string>} Gas price in WEI (hex string)
    */
-  async getGasPriceInHex(
+  async getGasPrice(
     type: TxType = 'other',
     speed: LegacyGasPriceKey = 'fast',
     bumpPercent: number = 0,
   ): Promise<string> {
-    const gasPrice = await this.getGasPrice(type, speed, bumpPercent);
-    return calculateGasPriceInWei(gasPrice).toHexString();
+    const gasPriceParams = await this.getGasPriceParams(type, speed, bumpPercent);
+    return calculateGasPriceInWei(gasPriceParams).toHexString();
   }
 
   /**
    * Estimates gas limit for transaction (or basic gas limit, if no tx data provided)
    * @param {TransactionData} tx Transaction data (object in web3 / ethers format)
    * @param {TxType} type Tornado transaction type: withdrawal by user, withdrawal by relayer, relayer fee check or 'other'
-   * @returns {Promise<BigNumber>} Gas limit
+   * @returns {Promise<number>} Gas limit
    */
-  abstract getGasLimit(tx?: TransactionData, type?: TxType): Promise<BigNumber>;
+  abstract getGasLimit(tx?: TransactionData, type?: TxType): Promise<number>;
 
   /**
    * If user withdraw non-native tokens on ETH or Goerli, we need to calculate refund value:
@@ -106,11 +106,12 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
    *
    * Refund needed that recipient can use tokens after withdrawal (covers gas fee for send/swap)
    * @param {TransactionData} [tx] Transaction data (object in web3 / ethers format)
-   * @param {TxType} [type] Tornado transaction type: withdrawal by user, withdrawal by relayer, relayer fee check or 'other'
-   * @returns {Promise<BigNumber>} Refund amount in WEI
+   * @returns {Promise<string>} Refund amount in WEI (hexed number)
    */
-  async calculateRefundInETH(tx?: TransactionData, type?: TxType): Promise<BigNumber> {
-    return (await this.getGas(tx, type)).mul(2);
+  async calculateRefundInETH(tx?: TransactionData): Promise<string> {
+    // In Tornado we need to calculate refund only on user side, relayer get refund value in proof
+    const gas = await this.getGas(tx, 'user_withdrawal');
+    return BigNumber.from(gas).mul(2).toHexString();
   }
 
   /**
@@ -118,17 +119,15 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
    * @param {BigNumberish} tokenPriceInEth Token price in WEI in native currency
    * @param {string | number} tokenDecimals Token (currency) decimals
    * @param {TransactionData} [tx] Transaction data (object in web3 / ethers format)
-   * @param {TxType} [type] Tornado transaction type: withdrawal by user, withdrawal by relayer, relayer fee check or 'other'
-   * @returns {Promise<BigNumber>} Refund amount in WEI in selected token
+   * @returns {Promise<string>} Refund amount in WEI in selected token (hexed number)
    */
   async calculateRefundInToken(
     tokenPriceInEth: BigNumberish,
     tokenDecimals: string | number,
     tx?: TransactionData,
-    type?: TxType,
-  ): Promise<BigNumber> {
-    const refundInEth = await this.calculateRefundInETH(tx, type);
-    return convertETHToToken(refundInEth, tokenDecimals, tokenPriceInEth);
+  ): Promise<string> {
+    const refundInEth = await this.calculateRefundInETH(tx);
+    return convertETHToToken(refundInEth, tokenDecimals, tokenPriceInEth).toHexString();
   }
 
   /**
@@ -143,7 +142,7 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
    * @param {number | string } decimals Token (currency) decimals
    * @param {BigNumberish} [refund=0] Refund in ETH, if withdrawed other tokens on Mainnet (not ETH)
    * @param {BigNumberish} [tokenPriceInEth] If withdrawing other token on Mainnet or Goerli, need to provide token price in ETH (in WEI)
-   * @returns {Promise<BigNumber>} Fee in WEI
+   * @returns {Promise<string>} Fee in WEI (hexed string)
    */
   async calculateWithdrawalFeeViaRelayer(
     type: TxType,
@@ -154,8 +153,8 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
     decimals: string | number,
     refund: BigNumberish = 0,
     tokenPriceInEth?: BigNumberish,
-  ): Promise<BigNumber> {
-    const gasCosts = await this.getGas(tx, type);
+  ): Promise<string> {
+    const gasCosts = BigNumber.from(await this.getGas(tx, type));
 
     const relayerFee = parseUnits(amount.toString(), decimals)
       .mul(`${relayerFeePercent * 1e10}`)
@@ -164,13 +163,13 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
     if ((this.chainId === ChainId.MAINNET || this.chainId === ChainId.GOERLI) && currency.toLowerCase() != 'eth') {
       if (!tokenPriceInEth) {
         console.error('Token price is required argument, if not native chain token is withdrawed');
-        return BigNumber.from(0);
+        return '0';
       }
 
       const feeInEth = gasCosts.add(refund);
-      return convertETHToToken(feeInEth, decimals, tokenPriceInEth).add(relayerFee);
+      return convertETHToToken(feeInEth, decimals, tokenPriceInEth).add(relayerFee).toHexString();
     }
 
-    return gasCosts.add(relayerFee);
+    return gasCosts.add(relayerFee).toHexString();
   }
 }
diff --git a/src/feeOracleV4.ts b/src/feeOracleV4.ts
index 00ce7e4..d46ab00 100644
--- a/src/feeOracleV4.ts
+++ b/src/feeOracleV4.ts
@@ -17,17 +17,18 @@ export class TornadoFeeOracleV4 extends TornadoFeeOracle implements ITornadoFeeO
     super(chainId, rpcUrl, gasPriceOracle);
   }
 
-  async getGasLimit(tx?: TransactionData, type: TxType = 'other', bumpPercent?: number): Promise<BigNumber> {
-    if (type === 'user_withdrawal') return BigNumber.from(defaultWithdrawalGasLimit[this.chainId]);
+  async getGasLimit(tx?: TransactionData, type: TxType = 'other', bumpPercent?: number): Promise<number> {
+    if (type === 'user_withdrawal') return BigNumber.from(defaultWithdrawalGasLimit[this.chainId]).toNumber();
 
     // Need to bump relayer gas limit for transaction, because predefined gas limit to small to be 100% sure that transaction will be sent
     // This leads to fact that relayer often pays extra for gas from his own funds, however, this was designed by previous developers
-    if (type === 'relayer_withdrawal') return bump(defaultWithdrawalGasLimit[this.chainId], bumpPercent || 25);
+    if (type === 'relayer_withdrawal')
+      return bump(defaultWithdrawalGasLimit[this.chainId], bumpPercent || 25).toNumber();
     // For compatibility reasons, when wee check user-provided fee for V4 withdrawal transaction, we need dump gas limit
     // for about 20 percent,so that the transaction will be sent, even if it results in some loss for the relayer
-    if (type === 'relayer_withdrawal_check_v4') return bump(defaultWithdrawalGasLimit[this.chainId], -25);
-    if (!tx) return BigNumber.from(21_000);
+    if (type === 'relayer_withdrawal_check_v4') return bump(defaultWithdrawalGasLimit[this.chainId], -25).toNumber();
+    if (!tx) return 21_000;
 
-    return this.provider.estimateGas(tx);
+    return (await this.provider.estimateGas(tx)).toNumber();
   }
 }
diff --git a/src/feeOracleV5.ts b/src/feeOracleV5.ts
index b1b748a..9b29a72 100644
--- a/src/feeOracleV5.ts
+++ b/src/feeOracleV5.ts
@@ -1,8 +1,14 @@
-import { ChainId, defaultWithdrawalGasLimit } from './config';
+import { ChainId } from './config';
 import { TornadoFeeOracle } from './feeOracle';
-import { ITornadoFeeOracle, GasPrice, TransactionData, TxType, LegacyGasPrices, LegacyGasPriceKey } from './types';
+import {
+  ITornadoFeeOracle,
+  TransactionData,
+  TxType,
+  LegacyGasPrices,
+  LegacyGasPriceKey,
+  GasPriceParams,
+} from './types';
 import { GasPriceOracle } from '@tornado/gas-price-oracle';
-import { BigNumber } from 'ethers';
 import { bump } from './utils';
 import { TornadoFeeOracleV4 } from './feeOracleV4';
 
@@ -25,7 +31,7 @@ export class TornadoFeeOracleV5 extends TornadoFeeOracle implements ITornadoFeeO
     this.fallbackFeeOracle = new TornadoFeeOracleV4(chainId, rpcUrl, defaultGasPrices);
   }
 
-  async getGasLimit(tx?: TransactionData, type: TxType = 'other', bumpPercent: number = 20): Promise<BigNumber> {
+  async getGasLimit(tx?: TransactionData, type: TxType = 'other', bumpPercent: number = 20): Promise<number> {
     if (!tx || Object.keys(tx).length === 0) return this.fallbackFeeOracle.getGasLimit(tx, type, bumpPercent);
 
     /* Relayer gas limit must be lower so that fluctuations in gas price cannot lead to the fact that
@@ -37,18 +43,17 @@ export class TornadoFeeOracleV5 extends TornadoFeeOracle implements ITornadoFeeO
 
     try {
       const fetchedGasLimit = await this.provider.estimateGas(tx);
-      return bump(fetchedGasLimit, bumpPercent);
+      return bump(fetchedGasLimit, bumpPercent).toNumber();
     } catch (e) {
-      if (type.endsWith('withdrawal')) return bump(defaultWithdrawalGasLimit[this.chainId], bumpPercent);
-      return BigNumber.from(21_000);
+      return this.fallbackFeeOracle.getGasLimit(tx, type, bumpPercent);
     }
   }
 
-  async getGasPrice(
+  async getGasPriceParams(
     type: TxType = 'other',
     speed: LegacyGasPriceKey = 'fast',
     bumpPercent?: number,
-  ): Promise<GasPrice> {
+  ): Promise<GasPriceParams> {
     // Only if bump percent didn't provided (if user provides 0, no need to recalculate)
     if (bumpPercent === undefined) {
       switch (this.chainId) {
@@ -65,6 +70,6 @@ export class TornadoFeeOracleV5 extends TornadoFeeOracle implements ITornadoFeeO
       }
     }
 
-    return super.getGasPrice(type, speed, bumpPercent);
+    return super.getGasPriceParams(type, speed, bumpPercent);
   }
 }
diff --git a/src/index.ts b/src/index.ts
index 0af80b3..bbf0996 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,6 +1,3 @@
-import { bump } from './utils';
-
 export * from './feeOracleV4';
 export * from './feeOracleV5';
 export * from './tokenPriceOracle';
-export { bump };
diff --git a/src/tokenPriceOracle.ts b/src/tokenPriceOracle.ts
index 0906b7f..ec32d1c 100644
--- a/src/tokenPriceOracle.ts
+++ b/src/tokenPriceOracle.ts
@@ -1,5 +1,5 @@
 import { MultiCall } from './contracts/MulticallAbi';
-import { Token, TokenPrices, TokenSymbol } from './types';
+import { ITornadoPriceOracle, Token, TokenPrices, TokenSymbol } from './types';
 import { MulticallAbi, OffchainOracleAbi } from './contracts';
 import { getMultiCallContract, getOffchainOracleContract } from './contracts/factories';
 import { Provider } from '@ethersproject/abstract-provider';
@@ -34,7 +34,7 @@ const defaultTornadoTokenPrices: TokenPrices = {
   wbtc: '15659889148334216720',
 };
 
-export class TokenPriceOracle {
+export class TokenPriceOracle implements ITornadoPriceOracle {
   private oracle: OffchainOracleAbi;
   private multiCall: MulticallAbi;
   private provider: Provider;
@@ -64,7 +64,7 @@ export class TokenPriceOracle {
    * @param {Token[]} tokens Tokens array
    * @returns Valid structure to provide to MultiCall contract
    */
-  prepareCallData(tokens: Token[] = this.tokens): MultiCall.CallStruct[] {
+  private prepareCallData(tokens: Token[] = this.tokens): MultiCall.CallStruct[] {
     return tokens.map((token) => ({
       to: this.oracle.address,
       data: this.oracle.interface.encodeFunctionData('getRateToEth', [token.tokenAddress, true]),
diff --git a/src/types.ts b/src/types.ts
index 86e57d5..1935f02 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,10 +1,9 @@
-import { BigNumber, BigNumberish, BytesLike } from 'ethers';
-import { GasPriceKey } from '@tornado/gas-price-oracle/lib/services';
+import { BigNumberish, BytesLike } from 'ethers';
+import { GasPriceKey, GetTxGasParamsRes } from '@tornado/gas-price-oracle/lib/services';
 import { AvailableTokenSymbols } from '@tornado/tornado-config';
 
 export type LegacyGasPriceKey = GasPriceKey;
-// Gas Prices in WEI
-export type GasPrice = { maxFeePerGas: BigNumberish; maxPriorityFeePerGas: BigNumberish } | { gasPrice: BigNumberish };
+export type GasPriceParams = GetTxGasParamsRes;
 export type LegacyGasPrices = {
   [gasPriceType in LegacyGasPriceKey]: number;
 };
@@ -32,17 +31,16 @@ export interface TransactionData {
 }
 
 export interface ITornadoFeeOracle {
-  getGas: (tx?: TransactionData, type?: TxType) => Promise<BigNumber>;
-  getGasPrice: (type?: TxType, speed?: LegacyGasPriceKey, bumpPercent?: number) => Promise<GasPrice>;
-  getGasPriceInHex: (type?: TxType, speed?: LegacyGasPriceKey, bumpPercent?: number) => Promise<string>;
-  getGasLimit: (tx?: TransactionData, type?: TxType, bumpPercent?: number) => Promise<BigNumber>;
-  calculateRefundInETH: (tx?: TransactionData, type?: TxType) => Promise<BigNumber>;
+  getGas: (tx?: TransactionData, type?: TxType) => Promise<string>;
+  getGasPriceParams: (type?: TxType, speed?: LegacyGasPriceKey, bumpPercent?: number) => Promise<GasPriceParams>;
+  getGasPrice: (type?: TxType, speed?: LegacyGasPriceKey, bumpPercent?: number) => Promise<string>;
+  getGasLimit: (tx?: TransactionData, type?: TxType, bumpPercent?: number) => Promise<number>;
+  calculateRefundInETH: (tx?: TransactionData) => Promise<string>;
   calculateRefundInToken: (
     tokenPriceInEth: BigNumberish,
     tokenDecimals: string | number,
     tx?: TransactionData,
-    type?: TxType,
-  ) => Promise<BigNumber>;
+  ) => Promise<string>;
   calculateWithdrawalFeeViaRelayer: (
     type: TxType,
     tx: TransactionData,
@@ -52,7 +50,12 @@ export interface ITornadoFeeOracle {
     decimals: number,
     refund: BigNumberish,
     tokenPriceInEth?: BigNumberish,
-  ) => Promise<BigNumber>;
+  ) => Promise<string>;
+}
+
+export interface ITornadoPriceOracle {
+  defaultPrices: TokenPrices;
+  fetchPrices: (tokens?: Token[]) => Promise<TokenPrices>;
 }
 
 export type WithdrawalData = {
diff --git a/src/utils.ts b/src/utils.ts
index b7768c7..05b42d9 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,5 +1,5 @@
 import { serialize } from '@ethersproject/transactions';
-import { GasPrice, TransactionData } from './types';
+import { GasPriceParams, TransactionData } from './types';
 import { BigNumber, BigNumberish } from 'ethers';
 import BigNumberFloat from 'bignumber.js';
 BigNumberFloat.config({ EXPONENTIAL_AT: 100 });
@@ -13,7 +13,7 @@ export function serializeTx(tx?: TransactionData | string): string {
   return serialize(tx);
 }
 
-export function calculateGasPriceInWei(gasPrice: GasPrice): BigNumber {
+export function calculateGasPriceInWei(gasPrice: GasPriceParams): BigNumber {
   // @ts-ignore
   return BigNumber.from(gasPrice.gasPrice || gasPrice.maxFeePerGas);
 }