diff --git a/lib/Cargo.toml b/lib/Cargo.toml
index a7ba2fd..f41c00d 100644
--- a/lib/Cargo.toml
+++ b/lib/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rs-firebase-admin-sdk"
-version = "4.0.1"
+version = "4.1.0"
 rust-version = "1.85"
 edition = "2024"
 authors = ["Kostas Petrikas"]
diff --git a/lib/src/auth/test.rs b/lib/src/auth/test.rs
index 4ff13bb..91f5887 100644
--- a/lib/src/auth/test.rs
+++ b/lib/src/auth/test.rs
@@ -7,7 +7,6 @@ use super::{
 };
 use crate::App;
 use crate::client::ReqwestApiClient;
-use crate::credentials::emulator::EmulatorCredentials;
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 use serial_test::serial;
@@ -17,7 +16,7 @@ use std::collections::BTreeMap;
 use time::Duration;
 use tokio;
 
-fn get_auth_service() -> FirebaseAuth<ReqwestApiClient<EmulatorCredentials>> {
+fn get_auth_service() -> FirebaseAuth<ReqwestApiClient> {
     App::emulated().auth("http://emulator:9099".parse().unwrap())
 }
 
diff --git a/lib/src/client/mod.rs b/lib/src/client/mod.rs
index fa4b962..1b1e242 100644
--- a/lib/src/client/mod.rs
+++ b/lib/src/client/mod.rs
@@ -7,7 +7,7 @@ use crate::credentials::get_headers;
 use bytes::Bytes;
 use error::{ApiClientError, FireBaseAPIErrorResponse};
 use error_stack::{Report, ResultExt};
-use google_cloud_auth::credentials::CredentialsProvider;
+use google_cloud_auth::credentials::Credentials;
 use http::Method;
 use serde::{Serialize, de::DeserializeOwned};
 use std::future::Future;
@@ -67,13 +67,13 @@ impl<T: Serialize> SetReqBody<T> for reqwest::RequestBuilder {
     }
 }
 
-pub struct ReqwestApiClient<C> {
+pub struct ReqwestApiClient {
     client: reqwest::Client,
-    credentials: C,
+    credentials: Credentials,
 }
 
-impl<C: CredentialsProvider> ReqwestApiClient<C> {
-    pub fn new(client: reqwest::Client, credentials: C) -> Self {
+impl ReqwestApiClient {
+    pub fn new(client: reqwest::Client, credentials: Credentials) -> Self {
         Self {
             client,
             credentials,
@@ -117,7 +117,7 @@ impl<C: CredentialsProvider> ReqwestApiClient<C> {
     }
 }
 
-impl<C: CredentialsProvider + Send + Sync + 'static> ApiHttpClient for ReqwestApiClient<C> {
+impl ApiHttpClient for ReqwestApiClient {
     async fn send_request<ResponseT: Send + DeserializeOwned>(
         &self,
         url: String,
diff --git a/lib/src/credentials/mod.rs b/lib/src/credentials/mod.rs
index 96b746d..f7fa1dc 100644
--- a/lib/src/credentials/mod.rs
+++ b/lib/src/credentials/mod.rs
@@ -3,7 +3,7 @@
 pub mod emulator;
 
 use error_stack::{Report, ResultExt};
-use google_cloud_auth::credentials::{CacheableResource, CredentialsProvider};
+use google_cloud_auth::credentials::{CacheableResource, Credentials};
 use headers::HeaderMapExt;
 use headers::{Header, HeaderName, HeaderValue};
 use http::{Extensions, HeaderMap};
@@ -47,7 +47,7 @@ impl Header for GoogleUserProject {
 }
 
 pub(crate) async fn get_project_id(
-    creds: &impl CredentialsProvider,
+    creds: &Credentials,
 ) -> Result<String, Report<GCPCredentialsError>> {
     let headers = get_headers(creds).await?;
 
@@ -59,7 +59,7 @@ pub(crate) async fn get_project_id(
 }
 
 pub(crate) async fn get_headers(
-    creds: &impl CredentialsProvider,
+    creds: &Credentials,
 ) -> Result<HeaderMap, Report<GCPCredentialsError>> {
     let headers = creds
         .headers(Extensions::new())
diff --git a/lib/src/lib.rs b/lib/src/lib.rs
index 34c05cb..c30108f 100644
--- a/lib/src/lib.rs
+++ b/lib/src/lib.rs
@@ -8,24 +8,22 @@ pub mod util;
 
 use auth::FirebaseAuth;
 use client::ReqwestApiClient;
+use core::marker::PhantomData;
 use credentials::{GCPCredentialsError, emulator::EmulatorCredentials, get_project_id};
 use error_stack::{Report, ResultExt};
-pub use google_cloud_auth::credentials::CredentialsProvider;
 use google_cloud_auth::credentials::{AccessTokenCredentials, Builder};
+pub use google_cloud_auth::credentials::{Credentials, CredentialsProvider};
 
 const FIREBASE_AUTH_SCOPES: [&str; 2] = [
     "https://www.googleapis.com/auth/cloud-platform",
     "https://www.googleapis.com/auth/userinfo.email",
 ];
 
-pub type LiveAuthAdmin = FirebaseAuth<ReqwestApiClient<AccessTokenCredentials>>;
-/// Default Firebase Auth Emulator admin manager
-pub type EmulatorAuthAdmin = FirebaseAuth<ReqwestApiClient<EmulatorCredentials>>;
-
 /// Base privileged manager for Firebase
 pub struct App<C> {
-    credentials: C,
+    credentials: Credentials,
     project_id: String,
+    _credentials_provider: PhantomData<C>,
 }
 
 impl App<EmulatorCredentials> {
@@ -34,15 +32,16 @@ impl App<EmulatorCredentials> {
         let credentials = EmulatorCredentials::default();
         Self {
             project_id: credentials.project_id.clone(),
-            credentials,
+            credentials: credentials.into(),
+            _credentials_provider: PhantomData,
         }
     }
 
     /// Firebase authentication manager for emulator
-    pub fn auth(&self, emulator_url: String) -> EmulatorAuthAdmin {
+    pub fn auth(&self, emulator_url: String) -> FirebaseAuth<ReqwestApiClient> {
         let client = ReqwestApiClient::new(reqwest::Client::new(), self.credentials.clone());
 
-        FirebaseAuth::emulated(emulator_url, &self.credentials.project_id, client)
+        FirebaseAuth::emulated(emulator_url, &self.project_id, client)
     }
 
     /// OIDC token verifier for emulator
@@ -55,10 +54,11 @@ impl App<EmulatorCredentials> {
 impl App<AccessTokenCredentials> {
     /// Create instance of Firebase app for live project
     pub async fn live() -> Result<Self, Report<GCPCredentialsError>> {
-        let credentials = Builder::default()
+        let credentials: Credentials = Builder::default()
             .with_scopes(FIREBASE_AUTH_SCOPES)
             .build_access_token_credentials()
-            .change_context(GCPCredentialsError)?;
+            .change_context(GCPCredentialsError)?
+            .into();
 
         let project_id = get_project_id(&credentials)
             .await
@@ -67,11 +67,12 @@ impl App<AccessTokenCredentials> {
         Ok(Self {
             credentials,
             project_id,
+            _credentials_provider: PhantomData,
         })
     }
 
     /// Create Firebase authentication manager
-    pub fn auth(&self) -> LiveAuthAdmin {
+    pub fn auth(&self) -> FirebaseAuth<ReqwestApiClient> {
         let client = ReqwestApiClient::new(reqwest::Client::new(), self.credentials.clone());
 
         FirebaseAuth::live(&self.project_id, client)