diff --git a/src/client.ts b/src/client.ts
index 98cebd0..2eb034a 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -10,6 +10,7 @@ export class SingleEthereum extends ISingleEthereum {
   public events: ISingleEthereum["events"] = new EventEmitter();
   public engine: ISingleEthereum["engine"];
   public metadata: ISingleEthereum["metadata"];
+  public chainId: ISingleEthereum["chainId"];
 
   static async init(opts: SingleEthereumTypes.Options) {
     const client = new SingleEthereum(opts);
@@ -24,6 +25,7 @@ export class SingleEthereum extends ISingleEthereum {
     this.name = opts.name || CLIENT_CONTEXT;
     this.core = opts.core;
     this.logger = this.core.logger;
+    this.chainId = opts.chainId;
     this.engine = new Engine(this);
   }
 
diff --git a/src/controllers/engine.ts b/src/controllers/engine.ts
index 032e50f..df07722 100644
--- a/src/controllers/engine.ts
+++ b/src/controllers/engine.ts
@@ -19,7 +19,7 @@ import {
 
 export class Engine extends ISingleEthereumEngine {
   public web3wallet: IWeb3Wallet;
-  public chainId?: number;
+  public chainId: number;
   private pendingInternalRequests: {
     id: number;
     resolve: <T>(value?: T | PromiseLike<T>) => void;
@@ -30,11 +30,13 @@ export class Engine extends ISingleEthereumEngine {
 
   constructor(client: ISingleEthereumEngine["client"]) {
     super(client);
+    this.chainId = 1;
     // initialized in init()
     this.web3wallet = {} as IWeb3Wallet;
   }
 
   public init = async () => {
+    this.chainId = this.client.chainId;
     this.web3wallet = await Web3Wallet.init({
       core: this.client.core,
       metadata: this.client.metadata,
diff --git a/src/types/client.ts b/src/types/client.ts
index c8adf0b..2abd709 100644
--- a/src/types/client.ts
+++ b/src/types/client.ts
@@ -52,6 +52,7 @@ export declare namespace SingleEthereumTypes {
     core: ICore;
     metadata: Metadata;
     name?: string;
+    chainId: number;
   }
 
   type Metadata = CoreTypes.Metadata;
@@ -95,6 +96,7 @@ export abstract class ISingleEthereum {
   public abstract logger: Logger;
   public abstract core: ICore;
   public abstract metadata: SingleEthereumTypes.Metadata;
+  public abstract chainId: number;
 
   constructor(public opts: SingleEthereumTypes.Options) {}
 
diff --git a/test/auth.spec.ts b/test/auth.spec.ts
index eeb27dd..25b922c 100644
--- a/test/auth.spec.ts
+++ b/test/auth.spec.ts
@@ -42,7 +42,7 @@ describe("Auth Integration", () => {
       metadata: {} as any,
       name: "dapp",
     });
-    wallet = await SingleEthereum.init({ core, name: "wallet", metadata: {} as any });
+    wallet = await SingleEthereum.init({ core, name: "wallet", metadata: {} as any, chainId: 1 });
     expect(wallet).to.be.exist;
     expect(dapp).to.be.exist;
     expect(core).to.be.exist;
diff --git a/test/sign.spec.ts b/test/sign.spec.ts
index 048f080..3fa2b34 100644
--- a/test/sign.spec.ts
+++ b/test/sign.spec.ts
@@ -58,6 +58,7 @@ describe("Sign Integration", () => {
       core,
       name: "wallet",
       metadata: {} as any,
+      chainId: 1,
     });
     await new Promise((resolve) => setTimeout(resolve, 1000));
     expect(wallet).to.be.exist;
@@ -284,6 +285,7 @@ describe("Sign Integration", () => {
       core,
       name: "wallet",
       metadata: {} as any,
+      chainId: 1,
     });
 
     // first pair and approve session
@@ -670,6 +672,7 @@ describe("Sign Integration", () => {
       core,
       name: "wallet",
       metadata: {} as any,
+      chainId: 1,
     });
     const expectedError = getSdkError("UNSUPPORTED_CHAINS");
     await Promise.all([
@@ -707,6 +710,7 @@ describe("Sign Integration", () => {
       core,
       name: "wallet",
       metadata: {} as any,
+      chainId: 1,
     });
     const expectedError = getSdkError("UNSUPPORTED_NAMESPACE_KEY");
     await Promise.all([
@@ -744,6 +748,7 @@ describe("Sign Integration", () => {
       core,
       name: "wallet",
       metadata: {} as any,
+      chainId: 1,
     });
     await Promise.all([
       new Promise<void>((resolve) => {