diff --git a/backend/src/stellar/stellar.exceptions.ts b/backend/src/stellar/stellar.exceptions.ts
new file mode 100644
index 0000000..0fc5db5
--- /dev/null
+++ b/backend/src/stellar/stellar.exceptions.ts
@@ -0,0 +1,24 @@
+import { HttpException, HttpStatus } from '@nestjs/common';
+
+/**
+ * Custom exception for Stellar RPC errors
+ */
+export class StellarRpcException extends HttpException {
+  constructor(
+    message: string,
+    public readonly originalError?: any,
+    public readonly contractId?: string,
+    public readonly method?: string,
+  ) {
+    super(
+      {
+        message,
+        error: 'Stellar RPC Error',
+        originalError: originalError?.message || originalError,
+        contractId,
+        method,
+      },
+      HttpStatus.BAD_GATEWAY,
+    );
+  }
+}
\ No newline at end of file
diff --git a/backend/src/stellar/stellar.service.ts b/backend/src/stellar/stellar.service.ts
index 9823a17..64a0641 100644
--- a/backend/src/stellar/stellar.service.ts
+++ b/backend/src/stellar/stellar.service.ts
@@ -1,6 +1,18 @@
 import { Injectable, OnModuleInit, Logger } from '@nestjs/common';
-import { rpc, Contract } from '@stellar/stellar-sdk';
+import { rpc, Contract, Address, xdr } from '@stellar/stellar-sdk';
 import { ConfigService } from '../config/config.service';
+import { StellarRpcException } from './stellar.exceptions';
+import {
+  ChainType,
+  GetOwnerResult,
+  ResolveStellarResult,
+  GetChainAddressResult,
+  GetVaultBalanceResult,
+  GetScheduledPaymentResult,
+  IsVaultActiveResult,
+  GetCreatedAtResult,
+  ScheduledPayment,
+} from './stellar.types';
 
 @Injectable()
 export class StellarService implements OnModuleInit {
diff --git a/backend/src/stellar/stellar.types.ts b/backend/src/stellar/stellar.types.ts
new file mode 100644
index 0000000..103f86e
--- /dev/null
+++ b/backend/src/stellar/stellar.types.ts
@@ -0,0 +1,49 @@
+/**
+ * TypeScript interfaces for Stellar contract return types
+ */
+
+export enum ChainType {
+  Evm = 'Evm',
+  Bitcoin = 'Bitcoin',
+  Solana = 'Solana',
+  Cosmos = 'Cosmos',
+}
+
+export enum PrivacyMode {
+  Normal = 'Normal',
+  Shielded = 'Shielded',
+}
+
+export interface ScheduledPayment {
+  from: string;
+  to: string;
+  token: string;
+  amount: string;
+  release_at: number;
+  executed: boolean;
+}
+
+export interface VaultConfig {
+  owner: string;
+  token: string;
+  created_at: number;
+}
+
+export interface VaultState {
+  balance: string;
+  is_active: boolean;
+}
+
+export interface ResolveData {
+  wallet: string;
+  memo?: number;
+}
+
+// Contract method return types
+export type GetOwnerResult = string | null;
+export type ResolveStellarResult = string;
+export type GetChainAddressResult = string | null;
+export type GetVaultBalanceResult = string | null;
+export type GetScheduledPaymentResult = ScheduledPayment | null;
+export type IsVaultActiveResult = boolean | null;
+export type GetCreatedAtResult = number | null;
\ No newline at end of file