diff --git a/src/api/auth.rs b/src/api/auth.rs
index 44e9166..6e78fac 100644
--- a/src/api/auth.rs
+++ b/src/api/auth.rs
@@ -8,7 +8,7 @@ use crate::auth::{password, session};
 #[cfg(feature = "server")]
 use crate::auth::session::get_session_from_ctx;
 #[cfg(feature = "server")]
-use crate::api::utils::{db_conn_error, query_error};
+use crate::api::error::AppError;
 use crate::db::pool::get_conn;
 use crate::models::user::{PublicUser, User, UserRole};
 
@@ -90,12 +90,12 @@ pub async fn register(
         });
     }
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let admin_count: i64 = client
         .query_one("SELECT COUNT(*) FROM users WHERE role = 'admin'", &[])
         .await
-        .map_err(query_error)?
+        .map_err(AppError::query)?
         .get(0);
 
     if admin_count > 0 {
@@ -106,10 +106,7 @@ pub async fn register(
         });
     }
 
-    let password_hash = password::hash_password(&password).map_err(|e| {
-        tracing::error!("Register password hash failed: {:?}", e);
-        ServerFnError::new(format!("密码哈希失败: {}", e))
-    })?;
+    let password_hash = password::hash_password(&password).map_err(|_| AppError::Internal("密码处理失败"))?;
 
     let result = client
         .query_one(
@@ -156,7 +153,7 @@ pub async fn login(username: String, password: String) -> Result<AuthResponse, S
         }
     }
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let row = match client
         .query_opt(
@@ -174,15 +171,12 @@ pub async fn login(username: String, password: String) -> Result<AuthResponse, S
             });
         }
         Err(e) => {
-            return Err(query_error(e));
+            return Err(AppError::query(e).into());
         }
     };
 
     let password_hash: String = row.get("password_hash");
-    let valid = password::verify_password(&password, &password_hash).map_err(|e| {
-        tracing::error!("Login password verify failed: {:?}", e);
-        ServerFnError::new(format!("密码验证失败: {}", e))
-    })?;
+    let valid = password::verify_password(&password, &password_hash).map_err(|_| AppError::Internal("密码处理失败"))?;
 
     if !valid {
         return Ok(AuthResponse {
@@ -202,10 +196,7 @@ pub async fn login(username: String, password: String) -> Result<AuthResponse, S
             &[&user_id, &token, &expires_at],
         )
         .await
-        .map_err(|e| {
-            tracing::error!("Login session insert failed: {:?}", e);
-            ServerFnError::new(format!("创建 session 失败: {}", e))
-        })?;
+        .map_err(AppError::db_conn)?;
 
     let cookie = format!(
         "session={token}; HttpOnly; Path=/; Max-Age={}; SameSite=Lax",
@@ -228,9 +219,8 @@ pub async fn login(username: String, password: String) -> Result<AuthResponse, S
 pub async fn logout() -> Result<AuthResponse, ServerFnError> {
     let token = get_session_from_ctx();
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
-    // 清除 cookie
     if let Some(ctx) = dioxus::fullstack::FullstackContext::current() {
         ctx.add_response_header(
             SET_COOKIE,
@@ -238,15 +228,11 @@ pub async fn logout() -> Result<AuthResponse, ServerFnError> {
         );
     }
 
-    // 删除当前 session
     if let Some(t) = token {
         client
             .execute("DELETE FROM sessions WHERE token = $1", &[&t])
             .await
-            .map_err(|e| {
-                tracing::error!("Logout session delete failed: {:?}", e);
-                ServerFnError::new(format!("删除 session 失败: {}", e))
-            })?;
+            .map_err(AppError::query)?;
     }
 
     Ok(AuthResponse {
@@ -263,7 +249,7 @@ pub struct CurrentUserResponse {
 
 #[cfg(feature = "server")]
 pub async fn get_user_by_token(token: &str) -> Result<Option<User>, ServerFnError> {
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let row = client
         .query_opt(
@@ -274,7 +260,7 @@ pub async fn get_user_by_token(token: &str) -> Result<Option<User>, ServerFnErro
             &[&token],
         )
         .await
-        .map_err(query_error)?;
+        .map_err(AppError::query)?;
 
     let user = match row {
         Some(row) => {
@@ -302,10 +288,7 @@ pub async fn get_current_user() -> Result<CurrentUserResponse, ServerFnError> {
         None => return Ok(CurrentUserResponse { user: None }),
     };
 
-    let user = match get_user_by_token(&token).await? {
-        Some(u) => Some(PublicUser::from(u)),
-        None => None,
-    };
+    let user = get_user_by_token(&token).await?.map(PublicUser::from);
 
     Ok(CurrentUserResponse { user })
 }
diff --git a/src/api/error.rs b/src/api/error.rs
new file mode 100644
index 0000000..1c8ccb2
--- /dev/null
+++ b/src/api/error.rs
@@ -0,0 +1,88 @@
+use dioxus::prelude::ServerFnError;
+
+#[derive(Debug)]
+pub enum AppError {
+    Unauthorized(&'static str),
+    Forbidden(&'static str),
+    NotFound(&'static str),
+    DbConn(String),
+    Query(String),
+    Transaction(String),
+    Internal(&'static str),
+}
+
+impl AppError {
+    pub fn db_conn(e: impl std::fmt::Display) -> Self {
+        tracing::error!("DB connection failed: {e}");
+        AppError::DbConn(e.to_string())
+    }
+
+    pub fn query(e: impl std::fmt::Display) -> Self {
+        tracing::error!("Query failed: {e}");
+        AppError::Query(e.to_string())
+    }
+
+    pub fn tx(e: impl std::fmt::Display) -> Self {
+        tracing::error!("Transaction failed: {e}");
+        AppError::Transaction(e.to_string())
+    }
+}
+
+impl From<AppError> for ServerFnError {
+    fn from(err: AppError) -> ServerFnError {
+        let msg = match &err {
+            AppError::Unauthorized(m) => m.to_string(),
+            AppError::Forbidden(m) => m.to_string(),
+            AppError::NotFound(m) => m.to_string(),
+            AppError::DbConn(_) => "服务暂时不可用".to_string(),
+            AppError::Query(_) => "操作失败".to_string(),
+            AppError::Transaction(_) => "操作失败".to_string(),
+            AppError::Internal(m) => m.to_string(),
+        };
+        ServerFnError::new(msg)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn unauthorized_message_passthrough() {
+        let err: ServerFnError = AppError::Unauthorized("未登录").into();
+        let msg = err.to_string();
+        assert!(msg.contains("未登录"), "expected '未登录' in: {msg}");
+    }
+
+    #[test]
+    fn db_conn_hides_internal_details() {
+        let err: ServerFnError = AppError::db_conn("connection refused on port 5432").into();
+        let msg = err.to_string();
+        assert!(
+            !msg.contains("5432"),
+            "should not leak internal details: {msg}"
+        );
+        assert!(msg.contains("服务暂时不可用"), "expected generic message: {msg}");
+    }
+
+    #[test]
+    fn query_hides_sql_details() {
+        let err: ServerFnError = AppError::query("syntax error at SELECT * FROM").into();
+        let msg = err.to_string();
+        assert!(!msg.contains("SELECT"), "should not leak SQL: {msg}");
+    }
+
+    #[test]
+    fn forbidden_message_passthrough() {
+        let err: ServerFnError = AppError::Forbidden("权限不足").into();
+        let msg = err.to_string();
+        assert!(msg.contains("权限不足"), "expected '权限不足': {msg}");
+    }
+
+    #[test]
+    fn not_found_message_passthrough() {
+        let err: ServerFnError = AppError::NotFound("文章不存在").into();
+        let msg = err.to_string();
+        assert!(msg.contains("文章不存在"), "expected passthrough: {msg}");
+    }
+}
diff --git a/src/api/mod.rs b/src/api/mod.rs
index e918db9..8de4e81 100644
--- a/src/api/mod.rs
+++ b/src/api/mod.rs
@@ -1,8 +1,8 @@
 pub mod auth;
+pub mod error;
 pub mod image;
 pub mod markdown;
 pub mod posts;
 pub mod rate_limit;
 pub mod slug;
 pub mod upload;
-pub mod utils;
diff --git a/src/api/posts.rs b/src/api/posts.rs
index 4c15856..ffd3e92 100644
--- a/src/api/posts.rs
+++ b/src/api/posts.rs
@@ -1,9 +1,9 @@
-#![allow(clippy::unused_unit, deprecated, unused_imports)]
+#![allow(clippy::unused_unit, deprecated, unused_imports, clippy::too_many_arguments)]
 
 use dioxus::prelude::*;
 
 #[cfg(feature = "server")]
-use crate::api::utils::{db_conn_error, query_error, tx_error};
+use crate::api::error::AppError;
 #[cfg(feature = "server")]
 use crate::auth::session::get_session_from_ctx;
 use crate::db::pool::get_conn;
@@ -26,19 +26,16 @@ pub use crate::api::slug::{ensure_unique_slug, is_valid_slug, slugify};
 // ============================================================================
 
 #[cfg(feature = "server")]
-async fn get_current_admin_user() -> Result<User, ServerFnError> {
-    let token = match get_session_from_ctx() {
-        Some(t) => t,
-        None => return Err(ServerFnError::new("未登录")),
-    };
+async fn get_current_admin_user() -> Result<User, AppError> {
+    let token = get_session_from_ctx().ok_or(AppError::Unauthorized("未登录"))?;
 
-    let user = match crate::api::auth::get_user_by_token(&token).await? {
-        Some(u) => u,
-        None => return Err(ServerFnError::new("会话已过期")),
-    };
+    let user = crate::api::auth::get_user_by_token(&token)
+        .await
+        .map_err(AppError::query)?
+        .ok_or(AppError::Unauthorized("会话已过期"))?;
 
     if user.role != UserRole::Admin {
-        return Err(ServerFnError::new("权限不足"));
+        return Err(AppError::Forbidden("权限不足"));
     }
 
     Ok(user)
@@ -249,7 +246,7 @@ pub async fn create_post(
         _ => crate::api::slug::slugify(&title),
     };
 
-    let mut client = get_conn().await.map_err(db_conn_error)?;
+    let mut client = get_conn().await.map_err(AppError::db_conn)?;
 
     let final_slug = crate::api::slug::ensure_unique_slug(&client, &base_slug, None).await?;
     let rendered = crate::api::markdown::render_markdown_enhanced(&content_md);
@@ -266,7 +263,7 @@ pub async fn create_post(
         None
     };
 
-    let tx = client.transaction().await.map_err(tx_error)?;
+    let tx = client.transaction().await.map_err(AppError::db_conn)?;
 
     let row = tx
         .query_one(
@@ -286,10 +283,7 @@ pub async fn create_post(
             ],
         )
         .await
-        .map_err(|e| {
-            tracing::error!("create post failed: {:?}", e);
-            ServerFnError::new(format!("创建文章失败: {}", e))
-        })?;
+        .map_err(AppError::tx)?;
 
     let post_id: i32 = row.get(0);
 
@@ -308,10 +302,7 @@ pub async fn create_post(
                         &[&tag_name.as_str()],
                     )
                     .await
-                    .map_err(|e| {
-                        tracing::error!("create tag failed: {:?}", e);
-                        ServerFnError::new(format!("创建标签失败: {}", e))
-                    })?;
+                    .map_err(AppError::tx)?;
 
                 match row {
                     Some(r) => r.get(0),
@@ -319,13 +310,8 @@ pub async fn create_post(
                         let row = tx
                             .query_opt("SELECT id FROM tags WHERE name = $1", &[&tag_name.as_str()])
                             .await
-                            .map_err(|e| {
-                                tracing::error!("query tag failed: {:?}", e);
-                                ServerFnError::new(format!("查询标签失败: {}", e))
-                            })?;
-                        row.map(|r| r.get(0)).ok_or_else(|| {
-                            ServerFnError::new(format!("标签不存在: {}", tag_name))
-                        })?
+                            .map_err(AppError::query)?;
+                        row.map(|r| r.get(0)).ok_or(AppError::NotFound("标签不存在"))?
                     }
                 }
             };
@@ -335,14 +321,11 @@ pub async fn create_post(
                 &[&post_id, &tag_id],
             )
             .await
-            .map_err(|e| {
-                tracing::error!("link tag failed: {:?}", e);
-                ServerFnError::new(format!("关联标签失败: {}", e))
-            })?;
+            .map_err(AppError::tx)?;
         }
     }
 
-    tx.commit().await.map_err(tx_error)?;
+    tx.commit().await.map_err(AppError::tx)?;
 
     // Invalidate caches after successful creation
     #[cfg(feature = "server")]
@@ -377,13 +360,12 @@ pub async fn update_post(
 ) -> Result<CreatePostResponse, ServerFnError> {
     let user = get_current_admin_user().await?;
 
-    let mut client = get_conn().await.map_err(db_conn_error)?;
+    let mut client = get_conn().await.map_err(AppError::db_conn)?;
 
-    // Get old slug before updating (for cache invalidation)
     let old_slug: Option<String> = client
         .query_opt("SELECT slug FROM posts WHERE id = $1", &[&post_id])
         .await
-        .map_err(query_error)?
+        .map_err(AppError::query)?
         .map(|r| r.get(0));
 
     let exists: bool = client
@@ -392,7 +374,7 @@ pub async fn update_post(
             &[&post_id, &user.id],
         )
         .await
-        .map_err(query_error)?
+        .map_err(AppError::query)?
         .is_some();
 
     if !exists {
@@ -429,9 +411,8 @@ pub async fn update_post(
     let post_status = PostStatus::from_str(&status).unwrap_or(PostStatus::Draft);
     let cover_image = cover_image.filter(|s| !s.trim().is_empty());
 
-    let tx = client.transaction().await.map_err(tx_error)?;
+    let tx = client.transaction().await.map_err(AppError::db_conn)?;
 
-    // Get old tags before deleting them (for cache invalidation)
     let old_tags: Vec<String> = {
         let rows = tx
             .query(
@@ -439,7 +420,7 @@ pub async fn update_post(
                 &[&post_id],
             )
             .await
-            .map_err(query_error)?;
+            .map_err(AppError::query)?;
         rows.iter().map(|r| r.get(0)).collect()
     };
 
@@ -449,7 +430,7 @@ pub async fn update_post(
             &[&post_id],
         )
         .await
-        .map_err(query_error)?;
+        .map_err(AppError::query)?;
 
     let published_at = if post_status == PostStatus::Published {
         let was_published = old_status_row
@@ -487,10 +468,7 @@ pub async fn update_post(
         ],
     )
     .await
-    .map_err(|e| {
-        tracing::error!("update post failed: {:?}", e);
-        ServerFnError::new(format!("更新文章失败: {}", e))
-    })?;
+    .map_err(AppError::tx)?;
 
     let tags_cleaned: Vec<String> = tags
         .into_iter()
@@ -502,10 +480,7 @@ pub async fn update_post(
 
     tx.execute("DELETE FROM post_tags WHERE post_id = $1", &[&post_id])
         .await
-        .map_err(|e| {
-            tracing::error!("delete old tags failed: {:?}", e);
-            ServerFnError::new(format!("删除旧标签失败: {}", e))
-        })?;
+        .map_err(AppError::tx)?;
 
     for tag_name in &tags_cleaned {
         let tag_id: i32 = {
@@ -515,10 +490,7 @@ pub async fn update_post(
                     &[&tag_name.as_str()],
                 )
                 .await
-                .map_err(|e| {
-                    tracing::error!("create tag failed: {:?}", e);
-                    ServerFnError::new(format!("创建标签失败: {}", e))
-                })?;
+                .map_err(AppError::tx)?;
 
             match row {
                 Some(r) => r.get(0),
@@ -526,12 +498,9 @@ pub async fn update_post(
                     let row = tx
                         .query_opt("SELECT id FROM tags WHERE name = $1", &[&tag_name.as_str()])
                         .await
-                        .map_err(|e| {
-                            tracing::error!("query tag failed: {:?}", e);
-                            ServerFnError::new(format!("查询标签失败: {}", e))
-                        })?;
+                        .map_err(AppError::query)?;
                     row.map(|r| r.get(0))
-                        .ok_or_else(|| ServerFnError::new(format!("标签不存在: {}", tag_name)))?
+                        .ok_or(AppError::NotFound("标签不存在"))?
                 }
             }
         };
@@ -541,13 +510,10 @@ pub async fn update_post(
             &[&post_id, &tag_id],
         )
         .await
-        .map_err(|e| {
-            tracing::error!("link tag failed: {:?}", e);
-            ServerFnError::new(format!("关联标签失败: {}", e))
-        })?;
+        .map_err(AppError::tx)?;
     }
 
-    tx.commit().await.map_err(tx_error)?;
+    tx.commit().await.map_err(AppError::tx)?;
 
     // Invalidate caches after successful update
     #[cfg(feature = "server")]
@@ -586,7 +552,7 @@ pub async fn update_post(
 pub async fn get_post_by_id(post_id: i32) -> Result<SinglePostResponse, ServerFnError> {
     let _user = get_current_admin_user().await?;
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let row = client
         .query_opt(
@@ -602,7 +568,7 @@ pub async fn get_post_by_id(post_id: i32) -> Result<SinglePostResponse, ServerFn
             &[&post_id],
         )
         .await
-        .map_err(query_error)?;
+        .map_err(AppError::query)?;
 
     let post = match row {
         Some(row) => Some(row_to_post_list(&client, &row).await),
@@ -618,7 +584,7 @@ pub async fn get_post_by_slug(slug: String) -> Result<SinglePostResponse, Server
         return Ok(SinglePostResponse { post: cached });
     }
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let row = client
         .query_opt(
@@ -652,7 +618,7 @@ pub async fn get_post_by_slug(slug: String) -> Result<SinglePostResponse, Server
             &[&slug],
         )
         .await
-        .map_err(query_error)?;
+        .map_err(AppError::query)?;
 
     let post = match row {
         Some(row) => Some(row_to_post_full(&client, &row).await),
@@ -675,7 +641,7 @@ pub async fn list_published_posts(
         return Ok(PostListResponse { posts: cached });
     }
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let offset = ((page - 1).max(0) as i64) * (per_page as i64);
     let limit = per_page as i64;
@@ -695,7 +661,7 @@ pub async fn list_published_posts(
             &[&limit, &offset],
         )
         .await
-        .map_err(query_error)?;
+        .map_err(AppError::query)?;
 
     let mut posts = Vec::new();
     for row in &rows {
@@ -710,7 +676,7 @@ pub async fn list_published_posts(
 pub async fn list_posts() -> Result<PostListResponse, ServerFnError> {
     let _user = get_current_admin_user().await?;
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let rows = client
         .query(
@@ -727,7 +693,7 @@ pub async fn list_posts() -> Result<PostListResponse, ServerFnError> {
             &[],
         )
         .await
-        .map_err(query_error)?;
+        .map_err(AppError::query)?;
 
     let mut posts = Vec::new();
     for row in &rows {
@@ -741,7 +707,7 @@ pub async fn list_posts() -> Result<PostListResponse, ServerFnError> {
 pub async fn delete_post(post_id: i32) -> Result<CreatePostResponse, ServerFnError> {
     let _user = get_current_admin_user().await?;
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let result = client
         .execute(
@@ -749,10 +715,7 @@ pub async fn delete_post(post_id: i32) -> Result<CreatePostResponse, ServerFnErr
             &[&post_id],
         )
         .await
-        .map_err(|e| {
-            tracing::error!("delete failed: {:?}", e);
-            ServerFnError::new(format!("删除失败: {}", e))
-        })?;
+        .map_err(AppError::tx)?;
 
     if result == 0 {
         return Ok(CreatePostResponse {
@@ -783,7 +746,7 @@ pub async fn list_tags() -> Result<TagListResponse, ServerFnError> {
         return Ok(TagListResponse { tags: cached });
     }
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let rows = client
         .query(
@@ -796,7 +759,7 @@ pub async fn list_tags() -> Result<TagListResponse, ServerFnError> {
             &[],
         )
         .await
-        .map_err(query_error)?;
+        .map_err(AppError::query)?;
 
     let tags: Vec<Tag> = rows
         .iter()
@@ -817,7 +780,7 @@ pub async fn get_posts_by_tag(tag_name: String) -> Result<PostListResponse, Serv
         return Ok(PostListResponse { posts: cached });
     }
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let rows = client
         .query(
@@ -836,7 +799,7 @@ pub async fn get_posts_by_tag(tag_name: String) -> Result<PostListResponse, Serv
             &[&tag_name],
         )
         .await
-        .map_err(query_error)?;
+        .map_err(AppError::query)?;
 
     let mut posts = Vec::new();
     for row in &rows {
@@ -855,12 +818,12 @@ pub async fn get_post_stats() -> Result<PostStatsResponse, ServerFnError> {
 
     let _user = get_current_admin_user().await?;
 
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let total: i64 = client
         .query_one("SELECT COUNT(*) FROM posts WHERE deleted_at IS NULL", &[])
         .await
-        .map_err(query_error)?
+        .map_err(AppError::query)?
         .get(0);
 
     let drafts: i64 = client
@@ -869,7 +832,7 @@ pub async fn get_post_stats() -> Result<PostStatsResponse, ServerFnError> {
             &[],
         )
         .await
-        .map_err(query_error)?
+        .map_err(AppError::query)?
         .get(0);
 
     let published: i64 = client
@@ -878,7 +841,7 @@ pub async fn get_post_stats() -> Result<PostStatsResponse, ServerFnError> {
             &[],
         )
         .await
-        .map_err(query_error)?
+        .map_err(AppError::query)?
         .get(0);
 
     let stats = PostStats {
@@ -892,7 +855,7 @@ pub async fn get_post_stats() -> Result<PostStatsResponse, ServerFnError> {
 
 #[server(SearchPosts, "/api")]
 pub async fn search_posts(query: String) -> Result<PostListResponse, ServerFnError> {
-    let client = get_conn().await.map_err(db_conn_error)?;
+    let client = get_conn().await.map_err(AppError::db_conn)?;
 
     let q = query.trim();
     if q.is_empty() {
@@ -917,7 +880,7 @@ pub async fn search_posts(query: String) -> Result<PostListResponse, ServerFnErr
             &[&q],
         )
         .await
-        .map_err(query_error)?;
+        .map_err(AppError::query)?;
 
     let mut posts = Vec::new();
     for row in &rows {
diff --git a/src/api/slug.rs b/src/api/slug.rs
index abd1f0f..2aa1659 100644
--- a/src/api/slug.rs
+++ b/src/api/slug.rs
@@ -41,7 +41,7 @@ pub async fn ensure_unique_slug(
     base: &str,
     exclude_id: Option<i32>,
 ) -> Result<String, ServerFnError> {
-    use crate::api::utils::query_error;
+    use crate::api::error::AppError;
 
     let mut candidate = base.to_string();
     let mut suffix = 2;
@@ -54,7 +54,7 @@ pub async fn ensure_unique_slug(
                     &[&candidate, &exclude],
                 )
                 .await
-                .map_err(query_error)?
+                .map_err(AppError::query)?
                 .is_some()
         } else {
             client
@@ -63,7 +63,7 @@ pub async fn ensure_unique_slug(
                     &[&candidate],
                 )
                 .await
-                .map_err(query_error)?
+                .map_err(AppError::query)?
                 .is_some()
         };
 
@@ -75,7 +75,7 @@ pub async fn ensure_unique_slug(
         suffix += 1;
 
         if candidate.len() > 200 {
-            return Err(ServerFnError::new("无法生成唯一 slug"));
+            return Err(AppError::Internal("无法生成唯一 slug").into());
         }
     }
 }
diff --git a/src/api/utils.rs b/src/api/utils.rs
deleted file mode 100644
index 93c4036..0000000
--- a/src/api/utils.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-#![allow(clippy::unused_unit)]
-
-#[cfg(feature = "server")]
-pub fn db_conn_error(e: impl std::fmt::Display) -> dioxus::prelude::ServerFnError {
-    tracing::error!("DB connection failed: {}", e);
-    dioxus::prelude::ServerFnError::new(format!("数据库连接失败: {}", e))
-}
-
-#[cfg(feature = "server")]
-pub fn query_error(e: impl std::fmt::Display) -> dioxus::prelude::ServerFnError {
-    tracing::error!("Query failed: {}", e);
-    dioxus::prelude::ServerFnError::new(format!("查询失败: {}", e))
-}
-
-#[cfg(feature = "server")]
-pub fn tx_error(e: impl std::fmt::Display) -> dioxus::prelude::ServerFnError {
-    tracing::error!("Transaction failed: {}", e);
-    dioxus::prelude::ServerFnError::new(format!("事务失败: {}", e))
-}
diff --git a/src/pages/admin/write.rs b/src/pages/admin/write.rs
index 628023e..ce0fdeb 100644
--- a/src/pages/admin/write.rs
+++ b/src/pages/admin/write.rs
@@ -211,6 +211,7 @@ fn write_editor(post_id: Option<i32>) -> Element {
     let on_submit = move |_| {
         if title().trim().is_empty() {
             error.set(Some("标题不能为空".to_string()));
+            #[allow(clippy::needless_return)]
             return;
         }