diff --git a/Cargo.lock b/Cargo.lock
index 91475b9..a40a761 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -77,6 +77,7 @@ dependencies = [
  "shuttle-runtime",
  "sqlx",
  "tokio",
+ "tracing",
  "utoipa",
  "utoipa-axum",
  "utoipa-swagger-ui",
diff --git a/Cargo.toml b/Cargo.toml
index df06ded..79fd70e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,8 @@ edition = "2021"
 
 [features]
 default = ["shuttle-axum", "shuttle-runtime"]
-local = ["dotenv", "tokio"]
+local = ["dotenv", "tokio", "dummy-auth"]
+dummy-auth = []
 
 [dependencies]
 axum = { version = "0.8.1", features = ["macros", "multipart"] }
@@ -22,5 +23,6 @@ tokio = {version = "1.44.2", optional = true, features = ["full"] }
 utoipa = { version = "5.3.1", features = ["axum_extras", "chrono", "uuid", "decimal"] }
 utoipa-axum = "0.2.0"
 utoipa-swagger-ui = { version = "9.0.1", features = ["axum"] }
+tracing = "0.1.41"
 uuid = { version = "1.14.0", features = ["v4", "fast-rng", "serde"] }
 
diff --git a/src/auth.rs b/src/auth.rs
new file mode 100644
index 0000000..ae33b6e
--- /dev/null
+++ b/src/auth.rs
@@ -0,0 +1,75 @@
+use axum::{
+    extract::FromRequestParts,
+    http::{header, request::Parts, StatusCode},
+    response::{IntoResponse, Response},
+    Json,
+};
+use serde::Serialize;
+use tracing::error;
+
+/// Represents an authenticated user, extracted from the Authentication header.
+#[derive(Debug, Clone)]
+pub struct AuthUser {
+    /// The ID of the authenticated user.
+    pub user_id: String, // Or Uuid if you prefer and add the uuid crate
+}
+
+/// Custom rejection type for authentication errors.
+#[derive(Debug, Serialize)]
+pub struct AuthError {
+    message: String,
+}
+
+impl IntoResponse for AuthError {
+    fn into_response(self) -> Response {
+        (StatusCode::UNAUTHORIZED, Json(self)).into_response()
+    }
+}
+
+impl<S> FromRequestParts<S> for AuthUser
+where
+    S: Send + Sync,
+{
+    type Rejection = AuthError;
+
+    async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
+        // Extract the Authentication header
+        let auth_header = parts
+            .headers
+            .get(header::AUTHORIZATION) // Using standard AUTHORIZATION header for convention
+            .and_then(|value| value.to_str().ok());
+
+        match auth_header {
+            Some(header_value) => {
+                // Check if the header starts with "Bearer "
+                if let Some(token) = header_value.strip_prefix("Bearer ") {
+                    let token = token.trim();
+                    if token.is_empty() {
+                        error!("Bearer token is empty");
+                        Err(AuthError {
+                            message: "Invalid Bearer token".to_string(),
+                        })
+                    } else {
+                        // In a real scenario, you'd validate this token.
+                        // For this dummy implementation, the token itself is the user_id.
+                        Ok(AuthUser {
+                            user_id: token.to_string(),
+                        })
+                    }
+                } else {
+                    error!("Invalid authentication header format. Expected Bearer token.");
+                    Err(AuthError {
+                        message: "Invalid authentication header format. Expected Bearer token."
+                            .to_string(),
+                    })
+                }
+            }
+            None => {
+                error!("Authorization header missing");
+                Err(AuthError {
+                    message: "Authorization header required".to_string(),
+                })
+            }
+        }
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index daf5a36..eae9670 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,6 +3,9 @@ pub mod types;
 pub mod user;
 pub mod utils;
 
+#[cfg(feature = "dummy-auth")]
+pub mod auth;
+
 pub mod tags {
     pub static USER: &str = "User";
     pub static TAGS: &str = "Tags";
diff --git a/src/user/handlers.rs b/src/user/handlers.rs
index 91b0609..f55ed88 100644
--- a/src/user/handlers.rs
+++ b/src/user/handlers.rs
@@ -1,9 +1,12 @@
+#[cfg(feature = "dummy-auth")]
+use crate::auth::AuthUser;
 use axum::{
     extract::{Path, Query, State},
     http::StatusCode,
     Json,
 };
-use firebase_auth::FirebaseUser;
+#[cfg(not(feature = "dummy-auth"))]
+use firebase_auth::FirebaseUser as AuthUser;
 use serde::{Deserialize, Serialize};
 use sqlx::types::chrono::{DateTime, Utc};
 use utoipa::{IntoParams, ToSchema};
@@ -123,7 +126,7 @@ pub struct NemesisTag {
 )]
 pub async fn get_current_user(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser,
+    user: AuthUser,
 ) -> Result<Json<User>, Error> {
     let user_id = user.user_id;
 
@@ -177,7 +180,7 @@ pub async fn get_current_user(
 pub async fn get_user(
     State(state): State<ArchenemyState>,
     Path(user_id): Path<String>,
-    _user: FirebaseUser, // Ensure authenticated
+    _user: AuthUser, // Ensure authenticated
 ) -> Result<Json<User>, Error> {
     let maybe_user = utils::get_user_by_id(&state.pool, &user_id).await?;
 
@@ -225,7 +228,7 @@ pub async fn get_user(
 )]
 pub async fn update_current_user(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser,
+    user: AuthUser,
     Json(update): Json<UpdateUserRequest>,
 ) -> Result<Json<User>, Error> {
     let user_id = user.user_id;
@@ -270,7 +273,7 @@ pub async fn update_current_user(
 )]
 pub async fn get_all_tags(
     State(state): State<ArchenemyState>,
-    _user: FirebaseUser, // Ensure authenticated
+    _user: AuthUser, // Ensure authenticated
 ) -> Result<Json<Vec<TagCount>>, Error> {
     let tags = utils::get_all_tags(&state.pool).await?;
     Ok(Json(tags))
@@ -309,7 +312,7 @@ pub async fn get_all_tags(
 )]
 pub async fn get_nemesis_tags(
     State(state): State<ArchenemyState>,
-    _user: FirebaseUser, // Ensure authenticated
+    _user: AuthUser, // Ensure authenticated
     Path(tag_name): Path<String>,
     Query(pagination): Query<PaginationParams>,
 ) -> Result<Json<Vec<NemesisTag>>, Error> {
@@ -355,7 +358,7 @@ pub async fn get_nemesis_tags(
 pub async fn get_user_tags(
     State(state): State<ArchenemyState>,
     Path(user_id): Path<String>,
-    _user: FirebaseUser, // Ensure authenticated
+    _user: AuthUser, // Ensure authenticated
 ) -> Result<Json<Vec<UserTag>>, Error> {
     // Verify user exists
     let maybe_user = utils::get_user_by_id(&state.pool, &user_id).await?;
@@ -395,7 +398,7 @@ pub async fn get_user_tags(
 )]
 pub async fn get_current_user_tags(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser, // Ensure authenticated
+    user: AuthUser, // Ensure authenticated
 ) -> Result<Json<Vec<UserTag>>, Error> {
     // Verify user exists
     let maybe_user = utils::get_user_by_id(&state.pool, &user.user_id).await?;
@@ -443,7 +446,7 @@ pub async fn get_current_user_tags(
 )]
 pub async fn add_current_user_tag(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser,
+    user: AuthUser,
     Json(request): Json<AddTagRequest>,
 ) -> Result<Json<UserTag>, Error> {
     let user_id = user.user_id;
@@ -491,7 +494,7 @@ pub async fn add_current_user_tag(
 )]
 pub async fn remove_current_user_tags(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser,
+    user: AuthUser,
     Json(names): Json<Vec<String>>,
 ) -> Result<StatusCode, Error> {
     let user_id = user.user_id;
@@ -531,7 +534,7 @@ pub async fn remove_current_user_tags(
 )]
 pub async fn get_potential_nemeses(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser,
+    user: AuthUser,
     Query(pagination): Query<PaginationParams>,
 ) -> Result<Json<Vec<UserWithTags>>, Error> {
     let user_id = user.user_id;
@@ -590,7 +593,7 @@ pub async fn get_potential_nemeses(
 )]
 pub async fn like_user(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser,
+    user: AuthUser,
     Path(target_user_id): Path<String>,
 ) -> Result<Json<UserLike>, Error> {
     let user_id = user.user_id;
@@ -649,7 +652,7 @@ pub async fn like_user(
 )]
 pub async fn dislike_user(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser,
+    user: AuthUser,
     Path(target_user_id): Path<String>,
 ) -> Result<Json<UserDislike>, Error> {
     let user_id = user.user_id;
@@ -712,7 +715,7 @@ pub async fn dislike_user(
 )]
 pub async fn dislike_user_with_tags(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser,
+    user: AuthUser,
     Path(target_user_id): Path<String>,
     Json(request): Json<AddTagsRequest>,
 ) -> Result<Json<Vec<UserDislikeTag>>, Error> {
@@ -779,7 +782,7 @@ pub async fn dislike_user_with_tags(
 )]
 pub async fn get_liked_users(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser,
+    user: AuthUser,
     Query(pagination): Query<PaginationParams>,
 ) -> Result<Json<Vec<UserWithLikedAt>>, Error> {
     let user_id = user.user_id;
@@ -828,7 +831,7 @@ pub async fn get_liked_users(
 )]
 pub async fn get_disliked_users(
     State(state): State<ArchenemyState>,
-    user: FirebaseUser,
+    user: AuthUser,
     Query(pagination): Query<PaginationParams>,
 ) -> Result<Json<Vec<UserWithDislikedAt>>, Error> {
     let user_id = user.user_id;