diff --git a/ios/Wrappers/AuthParamsWrapper.swift b/ios/Wrappers/AuthParamsWrapper.swift
index 0c4fbe47..8ea33ea7 100644
--- a/ios/Wrappers/AuthParamsWrapper.swift
+++ b/ios/Wrappers/AuthParamsWrapper.swift
@@ -52,7 +52,7 @@ struct AuthParamsWrapper {
 			dbDirectory: dbDirectory,
 			historySyncUrl: historySyncUrl,
 			isSmartContractWallet: isSmartContractWallet,
-			chainId: blockNumber != nil ? UInt64(chainId!) : nil,
+			chainId: chainId != nil ? UInt64(chainId!) : nil,
 			blockNumber: blockNumber != nil ? UInt64(blockNumber!) : nil
 		)
 	}
diff --git a/src/index.ts b/src/index.ts
index 9715410b..167f8523 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -255,8 +255,8 @@ export async function createV3(
 
 export async function buildV3(
   address: string,
-  chainId?: number | undefined,
   environment: 'local' | 'dev' | 'production',
+  chainId?: number | undefined,
   appVersion?: string | undefined,
   enableV3?: boolean | undefined,
   dbEncryptionKey?: Uint8Array | undefined,
diff --git a/src/lib/Client.ts b/src/lib/Client.ts
index ca4dd7c3..f009d346 100644
--- a/src/lib/Client.ts
+++ b/src/lib/Client.ts
@@ -334,7 +334,7 @@ export class Client<
               if (signer.isSmartContractWallet()) {
                 await XMTPModule.receiveSCWSignature(
                   request.id,
-                  Buffer.from(signatureString)
+                  signatureString
                 )
               } else {
                 const eSig = splitSignature(signatureString)
@@ -438,8 +438,8 @@ export class Client<
     }
     const client = await XMTPModule.buildV3(
       address,
-      chainId,
       options.env,
+      chainId,
       options.appVersion,
       Boolean(options.enableV3),
       options.dbEncryptionKey,