diff --git a/firebase-auth/build.gradle b/firebase-auth/build.gradle
index badda96557..d44f9867e3 100644
--- a/firebase-auth/build.gradle
+++ b/firebase-auth/build.gradle
@@ -28,4 +28,6 @@ android {
 
 dependencies {
     api project(':play-services-basement')
+
+    annotationProcessor project(':safe-parcel-processor')
 }
diff --git a/firebase-auth/core/src/main/kotlin/org/microg/gms/firebase/auth/FirebaseAuthService.kt b/firebase-auth/core/src/main/kotlin/org/microg/gms/firebase/auth/FirebaseAuthService.kt
index ff4113332d..72b599f983 100644
--- a/firebase-auth/core/src/main/kotlin/org/microg/gms/firebase/auth/FirebaseAuthService.kt
+++ b/firebase-auth/core/src/main/kotlin/org/microg/gms/firebase/auth/FirebaseAuthService.kt
@@ -487,13 +487,27 @@ class FirebaseAuthServiceImpl(private val context: Context, override val lifecyc
     }
 
     override fun signInWithCredential(request: SignInWithCredentialAidlRequest, callbacks: IFirebaseAuthCallbacks) {
-        Log.d(TAG, "Not yet implemented: signInWithCredential")
-        callbacks.onFailure(Status(CommonStatusCodes.CANCELED, "Not supported"))
+        lifecycleScope.launchWhenStarted {
+            Log.d(TAG, "signInWithCredential request: ${request.request}")
+            try {
+                val tokenResult = client.verifyAssertion(request.request.requestUri, request.request.postBody, request.request.returnSecureToken, request.request.returnIdpCredential)
+                Log.d(TAG, "signInWithCredential callback: $tokenResult ")
+                val idToken = tokenResult.getString("idToken")
+                val refreshToken = tokenResult.getString("refreshToken")
+                val getTokenResponse = client.getTokenByRefreshToken(refreshToken).toGetTokenResponse()
+                val accountInfoResult = client.getAccountInfo(idToken = idToken).getJSONArray("users").getJSONObject(0).toGetAccountInfoUser()
+                Log.d(TAG, "signInWithCredential callback: onGetTokenResponseAndUser")
+                callbacks.onGetTokenResponseAndUser(getTokenResponse, accountInfoResult)
+            } catch (e: Exception) {
+                Log.w(TAG, "signInWithCredential callback: onFailure", e)
+                callbacks.onFailure(Status(CommonStatusCodes.INTERNAL_ERROR, e.message))
+            }
+        }
     }
 
     override fun signInWithCredentialCompat(verifyAssertionRequest: VerifyAssertionRequest, callbacks: IFirebaseAuthCallbacks) {
-        Log.d(TAG, "Not yet implemented: signInWithCredentialCompat")
-        callbacks.onFailure(Status(CommonStatusCodes.CANCELED, "Not supported"))
+        Log.d(TAG, "signInWithCredentialCompat verifyAssertionRequest: $verifyAssertionRequest")
+        signInWithCredential(SignInWithCredentialAidlRequest(verifyAssertionRequest), callbacks)
     }
 
     override fun signInWithCustomToken(request: SignInWithCustomTokenAidlRequest, callbacks: IFirebaseAuthCallbacks) {
diff --git a/firebase-auth/core/src/main/kotlin/org/microg/gms/firebase/auth/IdentityToolkitClient.kt b/firebase-auth/core/src/main/kotlin/org/microg/gms/firebase/auth/IdentityToolkitClient.kt
index ca391a6d20..072d4d9bf2 100644
--- a/firebase-auth/core/src/main/kotlin/org/microg/gms/firebase/auth/IdentityToolkitClient.kt
+++ b/firebase-auth/core/src/main/kotlin/org/microg/gms/firebase/auth/IdentityToolkitClient.kt
@@ -109,6 +109,13 @@ class IdentityToolkitClient(context: Context, private val apiKey: String, privat
                     .put("token", token)
                     .put("returnSecureToken", returnSecureToken))
 
+    suspend fun verifyAssertion(requestUri: String? = null, postBody: String? = null, returnSecureToken: Boolean = true, returnIdpCredential: Boolean = true): JSONObject =
+            request("verifyAssertion", JSONObject()
+                    .put("requestUri", requestUri)
+                    .put("postBody", postBody)
+                    .put("returnSecureToken", returnSecureToken)
+                    .put("returnIdpCredential", returnIdpCredential))
+
     suspend fun verifyPassword(email: String? = null, password: String? = null, tenantId: String? = null, returnSecureToken: Boolean = true): JSONObject =
             request("verifyPassword", JSONObject()
                     .put("email", email)
diff --git a/firebase-auth/src/main/java/com/google/firebase/auth/api/internal/SignInWithCredentialAidlRequest.java b/firebase-auth/src/main/java/com/google/firebase/auth/api/internal/SignInWithCredentialAidlRequest.java
index 94190acb77..8e45a2d689 100644
--- a/firebase-auth/src/main/java/com/google/firebase/auth/api/internal/SignInWithCredentialAidlRequest.java
+++ b/firebase-auth/src/main/java/com/google/firebase/auth/api/internal/SignInWithCredentialAidlRequest.java
@@ -5,8 +5,32 @@
 
 package com.google.firebase.auth.api.internal;
 
-import org.microg.safeparcel.AutoSafeParcelable;
+import android.os.Parcel;
+
+import androidx.annotation.NonNull;
+
+import com.google.android.gms.common.internal.safeparcel.AbstractSafeParcelable;
+import com.google.android.gms.common.internal.safeparcel.SafeParcelable;
+import com.google.android.gms.common.internal.safeparcel.SafeParcelableCreatorAndWriter;
+
+@SafeParcelable.Class
+public class SignInWithCredentialAidlRequest extends AbstractSafeParcelable {
+
+    @Field(1)
+    public VerifyAssertionRequest request;
+
+    public SignInWithCredentialAidlRequest(VerifyAssertionRequest request) {
+        this.request = request;
+    }
+
+    public SignInWithCredentialAidlRequest() {
+    }
+
+    @Override
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
+        CREATOR.writeToParcel(this, dest, flags);
+    }
+
+    public static final SafeParcelableCreatorAndWriter<SignInWithCredentialAidlRequest> CREATOR = findCreator(SignInWithCredentialAidlRequest.class);
 
-public class SignInWithCredentialAidlRequest extends AutoSafeParcelable {
-    public static final Creator<SignInWithCredentialAidlRequest> CREATOR = new AutoCreator<>(SignInWithCredentialAidlRequest.class);
 }
diff --git a/firebase-auth/src/main/java/com/google/firebase/auth/api/internal/VerifyAssertionRequest.java b/firebase-auth/src/main/java/com/google/firebase/auth/api/internal/VerifyAssertionRequest.java
index 47e3c22027..0a0b130ded 100644
--- a/firebase-auth/src/main/java/com/google/firebase/auth/api/internal/VerifyAssertionRequest.java
+++ b/firebase-auth/src/main/java/com/google/firebase/auth/api/internal/VerifyAssertionRequest.java
@@ -5,8 +5,55 @@
 
 package com.google.firebase.auth.api.internal;
 
-import org.microg.safeparcel.AutoSafeParcelable;
+import android.os.Parcel;
+
+import androidx.annotation.NonNull;
+
+import com.google.android.gms.common.internal.safeparcel.AbstractSafeParcelable;
+import com.google.android.gms.common.internal.safeparcel.SafeParcelable;
+import com.google.android.gms.common.internal.safeparcel.SafeParcelableCreatorAndWriter;
+
+@SafeParcelable.Class
+public class VerifyAssertionRequest extends AbstractSafeParcelable {
+
+    @Field(2)
+    public String requestUri;
+    @Field(3)
+    public String accessToken;
+    @Field(4)
+    public String idToken;
+    @Field(5)
+    public String instanceId;
+    @Field(6)
+    public String providerId;
+    @Field(7)
+    public String pendingIdToken;
+    @Field(8)
+    public String postBody;
+    @Field(9)
+    public String localId;
+    @Field(10)
+    public boolean returnIdpCredential;
+    @Field(11)
+    public boolean returnSecureToken;
+    @Field(12)
+    public String delegatedProjectNumber;
+    @Field(13)
+    public String sessionId;
+    @Field(14)
+    public String queryParameter;
+    @Field(15)
+    public String tenantId;
+    @Field(16)
+    public boolean returnRefreshToken;
+    @Field(17)
+    public String tenantProjectNumber;
+
+    @Override
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
+        CREATOR.writeToParcel(this, dest, flags);
+    }
+
+    public static final SafeParcelableCreatorAndWriter<VerifyAssertionRequest> CREATOR = findCreator(VerifyAssertionRequest.class);
 
-public class VerifyAssertionRequest extends AutoSafeParcelable {
-    public static final Creator<VerifyAssertionRequest> CREATOR = new AutoCreator<>(VerifyAssertionRequest.class);
 }