diff --git a/packages/frontend/src/lib/server/index.ts b/packages/frontend/src/lib/server/index.ts
index 46cfce6..4233dbd 100644
--- a/packages/frontend/src/lib/server/index.ts
+++ b/packages/frontend/src/lib/server/index.ts
@@ -1,3 +1,5 @@
+import type { ApiError } from "@issue/shared";
+
 export * as issue from "@/lib/server/issue";
 export * as organisation from "@/lib/server/organisation";
 export * as project from "@/lib/server/project";
@@ -5,7 +7,16 @@ export * as sprint from "@/lib/server/sprint";
 export * as timer from "@/lib/server/timer";
 export * as user from "@/lib/server/user";
 
-export type ServerQueryInput = {
-    onSuccess?: (data: any, res: Response) => void;
-    onError?: (error: string) => void;
+export type ServerQueryInput<T = unknown> = {
+    onSuccess?: (data: T, res: Response) => void;
+    onError?: (error: ApiError | string) => void;
 };
+
+export function parseError(error: ApiError | string): string {
+    if (typeof error === "string") return error;
+    if (error.details) {
+        const messages = Object.values(error.details).flat();
+        return messages.join(", ");
+    }
+    return error.error;
+}