diff --git a/src/chains/models.ts b/src/chains/models.ts
index db4fe29..daff6be 100644
--- a/src/chains/models.ts
+++ b/src/chains/models.ts
@@ -1,4 +1,4 @@
-import { ChainType } from "./chain.enums";
+import { ChainSymbol, ChainType } from "./chain.enums";
 
 /**
  * Contains blockchain's basic information
@@ -7,7 +7,7 @@ export interface BasicChainProperties {
   /**
    * The symbol of the chain representing one of the supported blockchain networks (e.g., "ETH" for Ethereum). For more details, see: {@link ChainSymbol}.
    */
-  chainSymbol: string;
+  chainSymbol: ChainSymbol;
   /**
    * Common Blockchain Id</br>
    * A 0x-prefixed hexadecimal string</br>
diff --git a/src/client/core-api/core-api-mapper.ts b/src/client/core-api/core-api-mapper.ts
index 190a91c..21678f9 100644
--- a/src/client/core-api/core-api-mapper.ts
+++ b/src/client/core-api/core-api-mapper.ts
@@ -1,4 +1,5 @@
 import { Chains } from "../../chains";
+import { ChainSymbol } from "../../chains/chain.enums";
 import {
   ChainDetails,
   ChainDetailsMap,
@@ -75,7 +76,7 @@ function mapMessengerKeyDtoToMessenger(dto: MessengerKeyDTO): Messenger | null {
 
 function mapTransferTimeFromDto(dto: TransferTimeDTO): TransferTime {
   return Object.entries(dto).reduce<TransferTime>((result, [key, value]) => {
-    result[key] = mapMessengerTransferTimeFromDto(value);
+    result[key as ChainSymbol] = mapMessengerTransferTimeFromDto(value);
     return result;
   }, {});
 }
diff --git a/src/client/core-api/core-api.model.ts b/src/client/core-api/core-api.model.ts
index 4ac239a..5a10683 100644
--- a/src/client/core-api/core-api.model.ts
+++ b/src/client/core-api/core-api.model.ts
@@ -1,3 +1,4 @@
+import { ChainSymbol } from "../../chains/chain.enums";
 import { PoolInfo } from "../../tokens-info";
 
 export type ChainDetailsResponse = Record<string, ChainDetailsDTO>;
@@ -97,8 +98,8 @@ export interface CheckAddressResponse {
 export interface TransferStatusResponse {
   txId: string;
 
-  sourceChainSymbol: string;
-  destinationChainSymbol: string;
+  sourceChainSymbol: ChainSymbol;
+  destinationChainSymbol: ChainSymbol;
 
   sendAmount: string;
   sendAmountFormatted: number;
@@ -155,8 +156,8 @@ export interface BridgeTransaction {
   isClaimable?: boolean;
 }
 
-export type PoolInfoResponse = Record<string, PoolInfo>;
-export type PendingInfoResponse = Record<string, TokenPendingInfoDTO>;
+export type PoolInfoResponse = Record<ChainSymbol, PoolInfo>;
+export type PendingInfoResponse = Partial<Record<ChainSymbol, TokenPendingInfoDTO>>;
 export type TokenPendingInfoDTO = Record<string, PendingInfoDTO>;
 
 export interface PendingInfoDTO {
diff --git a/src/tokens-info/tokens-info.model.ts b/src/tokens-info/tokens-info.model.ts
index 0aad1c8..f72a30b 100644
--- a/src/tokens-info/tokens-info.model.ts
+++ b/src/tokens-info/tokens-info.model.ts
@@ -1,3 +1,4 @@
+import { ChainSymbol } from "../chains/chain.enums";
 import { BasicChainProperties } from "../chains/models";
 import { Messenger } from "../client/core-api/core-api.model";
 
@@ -175,10 +176,12 @@ export interface PoolInfo {
  * Type representing transfer times for various blockchain chains.
  *
  * @typedef {Record<string, MessengerTransferTime>} TransferTime
- * @property {string} chainSymbol - The symbol of the chain representing one of the supported blockchain networks (e.g., "ETH" for Ethereum). For more details, see: {@link ChainSymbol}.
+ * @property {chain} chainSymbol
  * @property {MessengerTransferTime} transferTime - The average transfer time details for the specified chain.
  */
-export type TransferTime = Record<string, MessengerTransferTime>;
+export type TransferTime = {
+  [chain in ChainSymbol]?: MessengerTransferTime;
+};
 
 /**
  * Contains Avg transaction time withing different messenger protocols