diff --git a/FirebaseAuth/Sources/Backend/FIRAuthBackend.h b/FirebaseAuth/Sources/Backend/FIRAuthBackend.h
index 52dca974389a..407a332eba45 100644
--- a/FirebaseAuth/Sources/Backend/FIRAuthBackend.h
+++ b/FirebaseAuth/Sources/Backend/FIRAuthBackend.h
@@ -60,6 +60,8 @@
 @class FIRGetRecaptchaConfigResponse;
 @class FIRStartPasskeyEnrollmentRequest;
 @class FIRStartPasskeyEnrollmentResponse;
+@class FIRFinalizePasskeyEnrollmentRequest;
+@class FIRFinalizePasskeyEnrollmentResponse;
 
 @protocol FIRAuthBackendImplementation;
 @protocol FIRAuthBackendRPCIssuer;
@@ -266,6 +268,17 @@ endpoint.
 typedef void (^FIRStartPasskeyEnrollmentResponseCallback)(
     FIRStartPasskeyEnrollmentResponse *_Nullable response, NSError *_Nullable error);
 
+/**
+ @typedef FIRFinalizePasskeyEnrollmentResponseCallback
+ @brief The type of block used to return the result of a call to the startPasskeyEnrollment
+endpoint.
+ @param response The received response, if any.
+ @param error The error which occurred, if any.
+ @remarks One of response or error will be non-nil.
+ */
+typedef void (^FIRFinalizePasskeyEnrollmentResponseCallback)(
+    FIRFinalizePasskeyEnrollmentResponse *_Nullable response, NSError *_Nullable error);
+
 /** @class FIRAuthBackend
     @brief Simple static class with methods representing the backend RPCs.
     @remarks All callback blocks passed as method parameters are invoked asynchronously on the
@@ -471,6 +484,14 @@ typedef void (^FIRStartPasskeyEnrollmentResponseCallback)(
  */
 + (void)startPasskeyEnrollment:(FIRStartPasskeyEnrollmentRequest *)request
                       callback:(FIRStartPasskeyEnrollmentResponseCallback)callback;
+
+/** @fn finalizePasskeyEnrollment:callback:
+    @brief Sends the platform created public info to the finalizePasskeyEnrollment endpoint.
+    @param request The request parameters.
+    @param callback The callback.
+ */
++ (void)finalizePasskeyEnrollment:(FIRFinalizePasskeyEnrollmentRequest *)request
+                         callback:(FIRFinalizePasskeyEnrollmentResponseCallback)callback;
 #endif
 
 /** @fn revokeToken:callback:
@@ -656,6 +677,14 @@ typedef void (^FIRStartPasskeyEnrollmentResponseCallback)(
  */
 - (void)startPasskeyEnrollment:(FIRStartPasskeyEnrollmentRequest *)request
                       callback:(FIRStartPasskeyEnrollmentResponseCallback)callback;
+
+/** @fn finalizePasskeyEnrollment:callback:
+    @brief Calls the finalizePasskeyEnrollment endpoint, which is responsible for sending the platform credential details to GCIP backend to exchange the access token and refresh token.
+    @param request The request parameters.
+    @param callback The callback.
+ */
+- (void)finalizePasskeyEnrollment:(FIRFinalizePasskeyEnrollmentRequest *)request
+                         callback:(FIRFinalizePasskeyEnrollmentResponseCallback)callback;
 #endif
 
 /** @fn revokeToken:callback:
diff --git a/FirebaseAuth/Sources/Backend/FIRAuthBackend.m b/FirebaseAuth/Sources/Backend/FIRAuthBackend.m
index 53c98e00c0a7..f657f1f5cc5f 100644
--- a/FirebaseAuth/Sources/Backend/FIRAuthBackend.m
+++ b/FirebaseAuth/Sources/Backend/FIRAuthBackend.m
@@ -64,12 +64,16 @@
 #import "FirebaseAuth/Sources/Backend/RPC/FIRVerifyAssertionResponse.h"
 #import "FirebaseAuth/Sources/Backend/RPC/FIRVerifyClientRequest.h"
 #import "FirebaseAuth/Sources/Backend/RPC/FIRVerifyClientResponse.h"
+#import "FirebaseAuth/Sources/Backend/RPC/FIRStartPasskeyEnrollmentRequest.h"
+#import "FirebaseAuth/Sources/Backend/RPC/FIRStartPasskeyEnrollmentResponse.h"
 #import "FirebaseAuth/Sources/Backend/RPC/FIRVerifyCustomTokenRequest.h"
 #import "FirebaseAuth/Sources/Backend/RPC/FIRVerifyCustomTokenResponse.h"
 #import "FirebaseAuth/Sources/Backend/RPC/FIRVerifyPasswordRequest.h"
 #import "FirebaseAuth/Sources/Backend/RPC/FIRVerifyPasswordResponse.h"
 #import "FirebaseAuth/Sources/Backend/RPC/FIRVerifyPhoneNumberRequest.h"
 #import "FirebaseAuth/Sources/Backend/RPC/FIRVerifyPhoneNumberResponse.h"
+#import "FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentRequest.h"
+#import "FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentResponse.h"
 #import "FirebaseAuth/Sources/Utilities/FIRAuthErrorUtils.h"
 #import "FirebaseCore/Extension/FirebaseCoreInternal.h"
 
@@ -680,6 +684,10 @@ + (void)startPasskeyEnrollment:(FIRStartPasskeyEnrollmentRequest *)request
                       callback:(FIRStartPasskeyEnrollmentResponseCallback)callback {
   [[self implementation] startPasskeyEnrollment:request callback:callback];
 }
+  
++ (void)finalizePasskeyEnrollment:(FIRFinalizePasskeyEnrollmentRequest *)request callback:(FIRFinalizePasskeyEnrollmentResponseCallback)callback {
+  [[self implementation] finalizePasskeyEnrollment:request callback:callback];
+}
 #endif
 
 + (void)revokeToken:(FIRRevokeTokenRequest *)request
@@ -1122,6 +1130,20 @@ - (void)startPasskeyEnrollment:(FIRStartPasskeyEnrollmentRequest *)request
                  callback(response, nil);
                }];
 }
+
+- (void)finalizePasskeyEnrollment:(FIRFinalizePasskeyEnrollmentRequest *)request callback:(FIRFinalizePasskeyEnrollmentResponseCallback)callback {
+  FIRFinalizePasskeyEnrollmentResponse *response = [[FIRFinalizePasskeyEnrollmentResponse alloc] init];
+  [self callWithRequest:request
+               response:response
+               callback:^(NSError *error) {
+                 if (error) {
+                   callback(nil, error);
+                   return;
+                 }
+                 callback(response, nil);
+               }];
+}
+
 #endif
 
 - (void)revokeToken:(FIRRevokeTokenRequest *)request
diff --git a/FirebaseAuth/Sources/Backend/FIRAuthRPCResponse.h b/FirebaseAuth/Sources/Backend/FIRAuthRPCResponse.h
index 0fe981a6eae7..ee1a71fa1822 100644
--- a/FirebaseAuth/Sources/Backend/FIRAuthRPCResponse.h
+++ b/FirebaseAuth/Sources/Backend/FIRAuthRPCResponse.h
@@ -23,7 +23,7 @@ NS_ASSUME_NONNULL_BEGIN
  */
 @protocol FIRAuthRPCResponse <NSObject>
 
-/** @fn setFieldsWithDictionary:error:
+/** @fn setWithDictionary:error:
     @brief Sets the response instance from the decoded JSON response.
     @param dictionary The dictionary decoded from HTTP JSON response.
     @param error An out field for an error which occurred constructing the request.
diff --git a/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentRequest.h b/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentRequest.h
new file mode 100644
index 000000000000..f8558b14278b
--- /dev/null
+++ b/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentRequest.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import "FirebaseAuth/Sources/Backend/FIRAuthRPCRequest.h"
+#import "FirebaseAuth/Sources/Backend/FIRIdentityToolkitRequest.h"
+#import <AuthenticationServices/ASAuthorizationPlatformPublicKeyCredentialRegistration.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/** @class FIRFinalizePasskeyEnrollmentRequest
+    @brief Represents the parameters for the finalizePasskeyEnrollment endpoint.
+ */
+@interface FIRFinalizePasskeyEnrollmentRequest : FIRIdentityToolkitRequest <FIRAuthRPCRequest>
+
+/**
+ @property IDToken
+ @brief The raw user access token.
+ */
+@property(nonatomic, copy, readonly) NSString *IDToken;
+
+/**
+ @property name
+ @brief The passkey name.
+ */
+@property(nonatomic, copy, readonly) NSString *name;
+
+/**
+ @property credentialID
+ @brief The credential ID.
+ */
+@property(nonatomic, copy, readonly) NSString *credentialID;
+
+/**
+ @property clientDataJson
+ @brief The CollectedClientData object from the authenticator.
+ */
+@property(nonatomic, copy, readonly) NSString *clientDataJson;
+
+/**
+ 
+ @property attestationObject
+ @brief The attestation object from the authenticator.
+ */
+@property(nonatomic, copy, readonly) NSString *attestationObject;
+
+- (nullable instancetype)initWithIDToken:(NSString *)IDToken
+                                    name:(NSString *)name
+                            credentialID:(NSString *)credentialID
+                          clientDataJson:(NSString *)clientDataJson
+                       attestationObject:(NSString *)attestationObject
+                    requestConfiguration:(FIRAuthRequestConfiguration *)requestConfiguration;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentRequest.m b/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentRequest.m
new file mode 100644
index 000000000000..2cdad6d193a5
--- /dev/null
+++ b/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentRequest.m
@@ -0,0 +1,127 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import "FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentRequest.h"
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ @var kFinalizePasskeyEnrollmentEndPoint
+ @brief GCIP endpoint for finalizePasskeyEnrollment rpc
+ */
+static NSString *const kFinalizePasskeyEnrollmentEndPoint = @"accounts/passkeyEnrollment:finalize";
+
+/**
+ @var kTenantIDKey
+ @brief The key for the tenant id value in the request.
+ */
+static NSString *const kTenantIDKey = @"tenantId";
+
+/**
+ @var kIDTokenKey
+ @brief The key for idToken value in the request.
+ */
+static NSString *const kIDTokenKey = @"idToken";
+
+/**
+ @var kAuthRegistrationRespKey
+ @brief The key for registration object from the authenticator.
+ */
+static NSString *const kAuthRegistrationRespKey = @"authenticatorRegistrationResponse";
+
+/**
+ @var kNameKey
+ @brief The key of passkey name.
+ */
+static NSString *const kNameKey = @"name";
+
+/**
+ @var kCredentialIDKey
+ @brief The key for registered credential identifier.
+ */
+static NSString *const kCredentialIDKey = @"credentialId";
+
+/**
+ @var kAuthAttestationRespKey
+ @brief The key for attestation response from a FIDO authenticator.
+ */
+static NSString *const kAuthAttestationRespKey = @"authenticatorAttestationResponse";
+
+/**
+ @var kClientDataJsonKey
+ @brief The key for CollectedClientData object from the authenticator.
+ */
+static NSString *const kClientDataJsonKey = @"clientDataJson";
+
+/**
+ @var kAttestationObject
+ @brief The key for the attestation object from the authenticator.
+ */
+static NSString *const kAttestationObject = @"attestationObject";
+
+
+@implementation FIRFinalizePasskeyEnrollmentRequest
+
+- (nullable instancetype)initWithIDToken:(NSString *)IDToken
+                                    name:(NSString *)name
+                            credentialID:(NSString *)credentialID
+                          clientDataJson:(NSString *)clientDataJson
+                       attestationObject:(NSString *)attestationObject requestConfiguration:(FIRAuthRequestConfiguration *)requestConfiguration {
+  self = [super initWithEndpoint:kFinalizePasskeyEnrollmentEndPoint
+            requestConfiguration:requestConfiguration];
+  if (self) {
+    self.useIdentityPlatform = YES;
+    _IDToken = IDToken;
+    _name = name;
+    _credentialID = credentialID;
+    _clientDataJson = clientDataJson;
+    _attestationObject = attestationObject;
+  }
+  return self;
+}
+
+- (nullable id)unencodedHTTPRequestBodyWithError:(NSError *__autoreleasing _Nullable *)error {
+  NSMutableDictionary *postBody = [NSMutableDictionary dictionary];
+  NSMutableDictionary *authRegistrationResponse = [NSMutableDictionary dictionary];
+  NSMutableDictionary *authAttestationResponse = [NSMutableDictionary dictionary];
+  
+  if (_IDToken) {
+    postBody[kIDTokenKey] = _IDToken;
+  }
+  if (_name) {
+    postBody[kNameKey] = _name;
+  }
+  if (_credentialID) {
+    authRegistrationResponse[kCredentialIDKey] = _credentialID;
+  }
+  if (_clientDataJson) {
+    authAttestationResponse[kClientDataJsonKey] = _clientDataJson;
+  }
+  if (_attestationObject) {
+    authAttestationResponse[kAttestationObject] = _attestationObject;
+  }
+  if (self.tenantID) {
+    postBody[kTenantIDKey] = self.tenantID;
+  }
+  
+  authRegistrationResponse[kAuthAttestationRespKey] = authAttestationResponse;
+  postBody[kAuthRegistrationRespKey] = authRegistrationResponse;
+  
+  return [postBody copy];
+}
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentResponse.h b/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentResponse.h
new file mode 100644
index 000000000000..21c553bf9a8c
--- /dev/null
+++ b/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentResponse.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import "FirebaseAuth/Sources/Backend/FIRAuthRPCResponse.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ @class FIRFinalizePasskeyEnrollmentResponse
+ @brief Represents the response from the startPasskeyEnrollment endpoint.
+ */
+@interface FIRFinalizePasskeyEnrollmentResponse : NSObject <FIRAuthRPCResponse>
+
+/**
+ @property idToken
+ @brief The user raw access token.
+ */
+@property(nonatomic, readonly, copy) NSString *idToken;
+
+/**
+ @property refershToken
+ @brief Refresh token for the authenticated user.
+ */
+@property(nonatomic, copy, readonly) NSData *refreshToken;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentResponse.m b/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentResponse.m
new file mode 100644
index 000000000000..603560c99308
--- /dev/null
+++ b/FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentResponse.m
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import "FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentResponse.h"
+
+/**
+ @var kIDTokenKey
+ @brief The name of the field in the response JSON for id token.
+ */
+static const NSString *kIdTokenKey = @"idToken";
+
+/**
+ @var kRefreshTokenKey
+ @brief The name of the field in the response JSON for refresh token.
+ */
+static const NSString *kRefreshTokenKey = @"refreshToken";
+
+
+@implementation FIRFinalizePasskeyEnrollmentResponse
+
+- (BOOL)setWithDictionary:(nonnull NSDictionary *)dictionary
+                    error:(NSError *__autoreleasing _Nullable *_Nullable)error {
+  if (dictionary[kIdTokenKey] == nil) {
+    return NO;
+  }
+  if (dictionary[kRefreshTokenKey] == nil) {
+    return NO;
+  }
+  
+  _idToken = dictionary[kIdTokenKey];
+  _refreshToken = dictionary[kRefreshTokenKey];
+  return YES;
+}
+
+@end
diff --git a/FirebaseAuth/Tests/Unit/FIRFinalizePasskeyEnrollmentRequestTests.m b/FirebaseAuth/Tests/Unit/FIRFinalizePasskeyEnrollmentRequestTests.m
new file mode 100644
index 000000000000..cfe984ab53e9
--- /dev/null
+++ b/FirebaseAuth/Tests/Unit/FIRFinalizePasskeyEnrollmentRequestTests.m
@@ -0,0 +1,172 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import <TargetConditionals.h>
+#if TARGET_OS_IOS || TARGET_OS_TV || TARGET_OS_OSX || TARGET_OS_MACCATALYST
+
+#import <XCTest/XCTest.h>
+
+#import "FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentRequest.h"
+#import "FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentResponse.h"
+#import "FirebaseAuth/Sources/Public/FirebaseAuth/FIRAuthErrors.h"
+#import "FirebaseAuth/Tests/Unit/FIRFakeBackendRPCIssuer.h"
+
+/**
+ @var kTestAPIKey
+ @brief Fake API key used for testing.
+ */
+static NSString *const kTestAPIKey = @"APIKey";
+
+/**
+ @var kTestFirebaseAppID
+ @brief Fake Firebase app ID used for testing.
+ */
+static NSString *const kTestFirebaseAppID = @"appID";
+
+/**
+ @var kExpectedAPIURL
+ @brief The expected URL for the test calls.
+ */
+static NSString *const kExpectedAPIURL =
+    @"https://identitytoolkit.googleapis.com/v2/accounts/passkeyEnrollment:finalize?key=APIKey";
+
+/**
+ @var kIDToken
+ @brief Token representing the user's identity.
+ */
+static NSString *const kIDToken = @"testIDToken";
+
+/**
+ @var kIDTokenKey
+ @brief ID Token field.
+ */
+static NSString *const kIDTokenKey = @"idToken";
+
+/**
+ @var kName
+ @brief Passkey name.
+ */
+static NSString *const kName = @"testName";
+
+/**
+ @var kNameKey
+ @brief Passkey name field
+ */
+static NSString *const kNameKey = @"name";
+
+/**
+ @var kCredentialID
+ @brief credential ID.
+ */
+static NSString *const kCredentialID = @"testCredentialID";
+
+/**
+ @var kCredentialIDKey
+ @brief credential ID field.
+ */
+static NSString *const kCredentialIDKey = @"credentialId";
+
+/**
+ @var kRawAttestationObject
+ @brief Passkey attestation object.
+ */
+static NSString *const kRawAttestationObject = @"testRawAttestationObject";
+
+/**
+ @var kRawAttestationObjectKey
+ @brief  The key for the attestation object from the authenticator.
+ */
+static NSString *const kRawAttestationObjectKey = @"attestationObject";
+
+/**
+ @var kRawClientDataJSON
+ @brief CollectedClientData object from the authenticator.
+ */
+static NSString *const kRawClientDataJSON = @"testRawClientDataJSON";
+
+/**
+ @var kRawClientDataJSONKey
+ @brief The key for the attestation object from the authenticator.
+ */
+static NSString *const kRawClientDataJSONKey = @"clientDataJson";
+
+/**
+ @var kAuthRegistrationRespKey
+ @brief The registration object from the authenticator.
+ */
+static NSString *const kAuthRegistrationRespKey = @"authenticatorRegistrationResponse";
+
+/**
+ @var kAuthAttestationRespKey
+ @brief The key for attestation response from a FIDO authenticator.
+ */
+static NSString *const kAuthAttestationRespKey = @"authenticatorAttestationResponse";
+
+/**
+ @class FIRFinalizePasskeyEnrollmentRequestTests
+ @brief Tests for @c FIRFinalizePasskeyEnrollmentRequest.
+ */
+@interface FIRFinalizePasskeyEnrollmentRequestTests : XCTestCase
+@end
+
+@implementation FIRFinalizePasskeyEnrollmentRequestTests {
+  /**
+   @brief This backend RPC issuer is used to fake network responses for each test in the suite.
+   In the @c setUp method we initialize this and set @c FIRAuthBackend's RPC issuer to it.
+   */
+  FIRFakeBackendRPCIssuer *_RPCIssuer;
+
+  /**
+   @brief This is the request configuration used for testing.
+   */
+  FIRAuthRequestConfiguration *_requestConfiguration;
+}
+
+- (void)setUp {
+  [super setUp];
+  FIRFakeBackendRPCIssuer *RPCIssuer = [[FIRFakeBackendRPCIssuer alloc] init];
+  [FIRAuthBackend setDefaultBackendImplementationWithRPCIssuer:RPCIssuer];
+  _RPCIssuer = RPCIssuer;
+  _requestConfiguration = [[FIRAuthRequestConfiguration alloc] initWithAPIKey:kTestAPIKey
+                                                                        appID:kTestFirebaseAppID];
+}
+
+- (void)tearDown {
+  _RPCIssuer = nil;
+  _requestConfiguration = nil;
+  [FIRAuthBackend setDefaultBackendImplementationWithRPCIssuer:nil];
+  [super tearDown];
+}
+
+- (void)testFinalizePasskeyEnrollmentRequest {
+  if (@available(iOS 15.0, *)) {
+    FIRFinalizePasskeyEnrollmentRequest *request = [[FIRFinalizePasskeyEnrollmentRequest alloc] initWithIDToken:kIDToken name:kName credentialID:kCredentialID clientDataJson:kRawClientDataJSON attestationObject:kRawAttestationObject requestConfiguration:_requestConfiguration];
+    
+    [FIRAuthBackend finalizePasskeyEnrollment:request callback:^(FIRFinalizePasskeyEnrollmentResponse * _Nullable response, NSError * _Nullable error) {
+    }];
+    XCTAssertEqualObjects(_RPCIssuer.requestURL.absoluteString, kExpectedAPIURL);
+    XCTAssertNotNil(_RPCIssuer.decodedRequest);
+    XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kIDTokenKey], kIDToken);
+    XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kNameKey], kName);
+    XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kAuthRegistrationRespKey][kAuthAttestationRespKey][kRawClientDataJSONKey], kRawClientDataJSON);
+    XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kAuthRegistrationRespKey][kAuthAttestationRespKey][kRawAttestationObjectKey], kRawAttestationObject);
+    XCTAssertEqualObjects(_RPCIssuer.decodedRequest[kAuthRegistrationRespKey][kCredentialIDKey], kCredentialID);
+
+  }
+}
+
+@end
+#endif
diff --git a/FirebaseAuth/Tests/Unit/FIRFinalizePasskeyEnrollmentResponseTests.m b/FirebaseAuth/Tests/Unit/FIRFinalizePasskeyEnrollmentResponseTests.m
new file mode 100644
index 000000000000..0b461da39278
--- /dev/null
+++ b/FirebaseAuth/Tests/Unit/FIRFinalizePasskeyEnrollmentResponseTests.m
@@ -0,0 +1,221 @@
+/*
+ * Copyright 2023 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import <XCTest/XCTest.h>
+
+#if TARGET_OS_IOS || TARGET_OS_TV || TARGET_OS_OSX || TARGET_OS_MACCATALYST
+#import "FirebaseAuth/Sources/Public/FirebaseAuth/FIRAuthErrors.h"
+
+#import "FirebaseAuth/Sources/Backend/FIRAuthBackend.h"
+#import "FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentRequest.h"
+#import "FirebaseAuth/Sources/Backend/RPC/FIRFinalizePasskeyEnrollmentResponse.h"
+#import "FirebaseAuth/Sources/Utilities/FIRAuthInternalErrors.h"
+#import "FirebaseAuth/Tests/Unit/FIRFakeBackendRPCIssuer.h"
+/**
+ @var kTestAPIKey
+ @brief Fake API key used for testing.
+ */
+static NSString *const kTestAPIKey = @"APIKey";
+
+/**
+ @var kTestFirebaseAppID
+ @brief Fake Firebase app ID used for testing.
+ */
+static NSString *const kTestFirebaseAppID = @"appID";
+
+/**
+ @var kIDToken
+ @brief Token representing the user's identity.
+ */
+static NSString *const kIDToken = @"idToken";
+
+/**
+ @var kRefreshToken
+ @brief Refresh Token
+ */
+static NSString *const kRefreshToken = @"refreshToken";
+
+/**
+ @var kName
+ @brief Passkey name.
+ */
+static NSString *const kName = @"testName";
+
+/**
+ @var kCredentialID
+ @brief credential ID.
+ */
+static NSString *const kCredentialID = @"testCredentialID";
+
+/**
+ @var kRawAttestationObject
+ @brief Passkey attestation object.
+ */
+static NSString *const kRawAttestationObject = @"testRawAttestationObject";
+
+/**
+ @var kRawClientDataJSON
+ @brief Passkey client data json.
+ */
+static NSString *const kRawClientDataJSON = @"testRawClientDataJSON";
+
+/**
+ @class FIRFinalizePasskeyEnrollmentResponseTests
+ @brief Tests for @c FIRFinalizePasskeyEnrollmentResponse.
+ */
+@interface FIRFinalizePasskeyEnrollmentResponseTests : XCTestCase
+@end
+@implementation FIRFinalizePasskeyEnrollmentResponseTests {
+  /**
+   @brief This backend RPC issuer is used to fake network responses for each test in the suite.
+   In the @c setUp method we initialize this and set @c FIRAuthBackend's RPC issuer to it.
+   */
+  FIRFakeBackendRPCIssuer *_RPCIssuer;
+
+  /**
+   @brief This is the request configuration used for testing.
+   */
+  FIRAuthRequestConfiguration *_requestConfiguration;
+}
+
+- (void)setUp {
+  [super setUp];
+  FIRFakeBackendRPCIssuer *RPCIssuer = [[FIRFakeBackendRPCIssuer alloc] init];
+  [FIRAuthBackend setDefaultBackendImplementationWithRPCIssuer:RPCIssuer];
+  _RPCIssuer = RPCIssuer;
+  _requestConfiguration = [[FIRAuthRequestConfiguration alloc] initWithAPIKey:kTestAPIKey
+                                                                        appID:kTestFirebaseAppID];
+}
+
+- (void)tearDown {
+  _RPCIssuer = nil;
+  _requestConfiguration = nil;
+  [FIRAuthBackend setDefaultBackendImplementationWithRPCIssuer:nil];
+  [super tearDown];
+}
+
+/** @fn testSuccessfulFinalizePasskeyEnrollmentResponse
+    @brief This test simulates a successful @c FinalizePasskeyEnrollment flow.
+ */
+- (void)testSuccessfulFinalizePasskeyEnrollmentResponse {
+  if (@available(iOS 15.0, *)) {
+    FIRFinalizePasskeyEnrollmentRequest *request = [[FIRFinalizePasskeyEnrollmentRequest alloc] initWithIDToken:kIDToken name:kName credentialID:kCredentialID clientDataJson:kRawClientDataJSON attestationObject:kRawAttestationObject requestConfiguration:_requestConfiguration];
+
+    __block BOOL callbackInvoked;
+    __block FIRFinalizePasskeyEnrollmentResponse *RPCResponse;
+    __block NSError *RPCError;
+    
+    [FIRAuthBackend finalizePasskeyEnrollment:request
+                                  callback:^(FIRFinalizePasskeyEnrollmentResponse *_Nullable response,
+                                             NSError *_Nullable error) {
+      callbackInvoked = YES;
+      RPCResponse = response;
+      RPCError = error;
+    }];
+    
+    [_RPCIssuer respondWithJSON:@{
+      @"idToken" : kIDToken,
+      @"refreshToken": kRefreshToken,
+    }];
+    
+    XCTAssert(callbackInvoked);
+    XCTAssertNil(RPCError);
+    XCTAssertNotNil(RPCResponse);
+    XCTAssertEqualObjects(RPCResponse.idToken, kIDToken);
+    XCTAssertEqualObjects(RPCResponse.refreshToken, kRefreshToken);
+  }
+}
+
+/** @fn testFinalizePasskeyEnrollmentResponseMissingIDTokenError
+    @brief This test simulates an unexpected response returned from server in @c
+   FinalizePasskeyEnrollment flow.
+ */
+- (void)testFinalizePasskeyEnrollmentResponseMissingIDTokenError {
+  if (@available(iOS 15.0, *)) {
+    FIRFinalizePasskeyEnrollmentRequest *request = [[FIRFinalizePasskeyEnrollmentRequest alloc] initWithIDToken:kIDToken name:kName credentialID:kCredentialID clientDataJson:kRawClientDataJSON attestationObject:kRawAttestationObject requestConfiguration:_requestConfiguration];
+    
+    __block BOOL callbackInvoked;
+    __block FIRFinalizePasskeyEnrollmentResponse *RPCResponse;
+    __block NSError *RPCError;
+    
+    [FIRAuthBackend finalizePasskeyEnrollment:request
+                                     callback:^(FIRFinalizePasskeyEnrollmentResponse *_Nullable response,
+                                                NSError *_Nullable error) {
+      callbackInvoked = YES;
+      RPCResponse = response;
+      RPCError = error;
+    }];
+    
+    [_RPCIssuer respondWithJSON:@{
+      @"wrongkey" : @{},
+      @"refreshToken" : kRefreshToken,
+    }];
+    [self errorValidationHelperWithCallbackInvoked:callbackInvoked
+                                          rpcError:RPCError
+                                       rpcResponse:RPCResponse];
+  }
+}
+/** @fn testFinalizePasskeyEnrollmentResponseMissingRefreshTokenError
+    @brief This test simulates an unexpected response returned from server in @c
+ FinalizePasskeyEnrollment flow.
+ */
+- (void)testFinalizePasskeyEnrollmentResponseMissingRefreshTokenError {
+  if (@available(iOS 15.0, *)) {
+    FIRFinalizePasskeyEnrollmentRequest *request = [[FIRFinalizePasskeyEnrollmentRequest alloc]initWithIDToken:kIDToken name:kName credentialID:kCredentialID clientDataJson:kRawClientDataJSON attestationObject:kRawAttestationObject requestConfiguration:_requestConfiguration];
+
+    __block BOOL callbackInvoked;
+    __block FIRFinalizePasskeyEnrollmentResponse *RPCResponse;
+    __block NSError *RPCError;
+    
+    [FIRAuthBackend finalizePasskeyEnrollment:request
+                                     callback:^(FIRFinalizePasskeyEnrollmentResponse *_Nullable response,
+                                                NSError *_Nullable error) {
+      callbackInvoked = YES;
+      RPCResponse = response;
+      RPCError = error;
+    }];
+    
+    [_RPCIssuer respondWithJSON:@{
+      @"wrongkey" : @{},
+      @"idToken" : kIDToken,
+    }];
+    [self errorValidationHelperWithCallbackInvoked:callbackInvoked
+                                          rpcError:RPCError
+                                       rpcResponse:RPCResponse];
+  }
+}
+
+/** @fn errorValidationHelperWithCallbackInvoked:rpcError:rpcResponse:
+    @brief Helper function to validate the unexpected response returned from server in @c
+   FinalizePasskeyEnrollment flow.
+ */
+- (void)errorValidationHelperWithCallbackInvoked:(BOOL)callbackInvoked
+                                        rpcError:(NSError *)RPCError
+                                     rpcResponse:(FIRFinalizePasskeyEnrollmentResponse *)RPCResponse {
+  XCTAssert(callbackInvoked);
+  XCTAssertNotNil(RPCError);
+  XCTAssertEqualObjects(RPCError.domain, FIRAuthErrorDomain);
+  XCTAssertEqual(RPCError.code, FIRAuthErrorCodeInternalError);
+  XCTAssertNotNil(RPCError.userInfo[NSUnderlyingErrorKey]);
+  NSError *underlyingError = RPCError.userInfo[NSUnderlyingErrorKey];
+  XCTAssertNotNil(underlyingError);
+  XCTAssertNotNil(underlyingError.userInfo[FIRAuthErrorUserInfoDeserializedResponseKey]);
+  XCTAssertNil(RPCResponse);
+}
+
+@end
+#endif
+