diff --git a/frontend/chat-ui/src/api.js b/frontend/chat-ui/src/api.js
index 8cfb598..4c6bf67 100644
--- a/frontend/chat-ui/src/api.js
+++ b/frontend/chat-ui/src/api.js
@@ -1,5 +1,4 @@
 export const API_BASE_URL = import.meta.env.VITE_API_BASE_URL || '';
-const API_BASE_URL = import.meta.env.VITE_API_BASE_URL || '';
 const API_KEY = import.meta.env.VITE_API_KEY || '';
 
 async function request(method, path, body) {
diff --git a/frontend/chat-ui/src/components/ChatWindow.jsx b/frontend/chat-ui/src/components/ChatWindow.jsx
index f9c6f0b..070b8ca 100644
--- a/frontend/chat-ui/src/components/ChatWindow.jsx
+++ b/frontend/chat-ui/src/components/ChatWindow.jsx
@@ -13,8 +13,6 @@ import { useStore } from '../store';
 import MessageBubble from './MessageBubble.jsx';
 import { API_BASE_URL } from '../api';
 
-const API_BASE_URL = import.meta.env.VITE_API_BASE_URL || '';
-
 export default function ChatWindow() {
   const { state, dispatch } = useStore();
   const bottomRef = useRef();
@@ -31,7 +29,6 @@ export default function ChatWindow() {
       url.searchParams.set('api_key', apiKey);
     }
     const events = new EventSource(url.toString());
-    const events = new EventSource(`${API_BASE_URL}/stream/${state.currentConversation.id}`);
 
     const handleToken = (e) => {
       try {
diff --git a/frontend/chat-ui/src/components/InputBox.jsx b/frontend/chat-ui/src/components/InputBox.jsx
index a8efc41..b7a95e3 100644
--- a/frontend/chat-ui/src/components/InputBox.jsx
+++ b/frontend/chat-ui/src/components/InputBox.jsx
@@ -1,6 +1,5 @@
 import React, { useState, useRef } from 'react';
 import { useStore } from '../store';
-import { API_BASE_URL } from '../api';
 import { post } from '../api';
 
 export default function InputBox() {
diff --git a/frontend/chat-ui/src/components/MessageActions.jsx b/frontend/chat-ui/src/components/MessageActions.jsx
index 3ce6d96..85a3970 100644
--- a/frontend/chat-ui/src/components/MessageActions.jsx
+++ b/frontend/chat-ui/src/components/MessageActions.jsx
@@ -3,8 +3,7 @@ import { useStore } from '../store';
 
 /** @typedef {import('../types').Message} Message */
 
-const API_BASE_URL = import.meta.env.VITE_API_BASE_URL || '';
-import { API_BASE_URL } from '../api';
+import { post } from '../api';
 
 /**
  * Action buttons associated with a message.
@@ -24,13 +23,8 @@ export default function MessageActions({ message }) {
   const regenerate = async () => {
     if (!state.currentConversation) return;
     try {
-      await fetch(`${API_BASE_URL}/messages/${state.currentConversation.id}/regenerate`, {
-        method: 'POST',
-        headers: {
-          'Content-Type': 'application/json',
-          'x-api-key': import.meta.env.VITE_API_KEY,
-        },
-        body: JSON.stringify({ messageId: message.id }),
+      await post(`/messages/${state.currentConversation.id}/regenerate`, {
+        messageId: message.id,
       });
     } catch (e) {
       console.error(e);
@@ -39,14 +33,7 @@ export default function MessageActions({ message }) {
 
   const feedback = async (value) => {
     try {
-      await fetch(`${API_BASE_URL}/feedback`, {
-        method: 'POST',
-        headers: {
-          'Content-Type': 'application/json',
-          'x-api-key': import.meta.env.VITE_API_KEY,
-        },
-        body: JSON.stringify({ messageId: message.id, value }),
-      });
+      await post('/feedback', { messageId: message.id, value });
     } catch (e) {
       console.error(e);
     }
diff --git a/frontend/chat-ui/src/components/Sidebar.jsx b/frontend/chat-ui/src/components/Sidebar.jsx
index b158df6..a418b1d 100644
--- a/frontend/chat-ui/src/components/Sidebar.jsx
+++ b/frontend/chat-ui/src/components/Sidebar.jsx
@@ -16,9 +16,6 @@ import { useStore } from '../store';
  * @typedef {import('../types').Message} Message
  */
 
-const API_BASE_URL = import.meta.env.VITE_API_BASE_URL || '';
-
-import { API_BASE_URL } from '../api';
 import { get, post } from '../api';
 
 /**
@@ -56,13 +53,6 @@ export default function Sidebar() {
    */
   const openConversation = async (c) => {
     try {
-        const res = await fetch(`${API_BASE_URL}/messages/${c.id}`, {
-          headers: { 'x-api-key': import.meta.env.VITE_API_KEY },
-        });
-        const msgs = /** @type {Message[]} */ (await res.json());
-        dispatch({ type: 'SET_CURRENT_CONVERSATION', conversation: c });
-        dispatch({ type: 'SET_MESSAGES', messages: msgs });
-
       const msgs = await get(`/messages/${c.id}`);
       dispatch({ type: 'SET_CURRENT_CONVERSATION', conversation: c });
       dispatch({ type: 'SET_MESSAGES', messages: msgs });
diff --git a/frontend/chat-ui/src/components/TopBar.jsx b/frontend/chat-ui/src/components/TopBar.jsx
index ff06c03..f7968b3 100644
--- a/frontend/chat-ui/src/components/TopBar.jsx
+++ b/frontend/chat-ui/src/components/TopBar.jsx
@@ -1,6 +1,6 @@
 import React, { useState, useEffect } from 'react';
 import { useStore } from '../store';
-import { API_BASE_URL } from '../api';
+import { put, del } from '../api';
 
 export default function TopBar() {
   const { state, dispatch } = useStore();
@@ -16,14 +16,7 @@ export default function TopBar() {
     setTitle(t);
     if (!state.currentConversation) return;
     try {
-      await fetch(`${API_BASE_URL}/conversations/${state.currentConversation.id}`, {
-        method: 'PUT',
-        headers: {
-          'Content-Type': 'application/json',
-          'x-api-key': import.meta.env.VITE_API_KEY,
-        },
-        body: JSON.stringify({ title: t }),
-      });
+      await put(`/conversations/${state.currentConversation.id}`, { title: t });
       const updated = { ...state.currentConversation, title: t };
       dispatch({ type: 'SET_CURRENT_CONVERSATION', conversation: updated });
       dispatch({
@@ -38,10 +31,7 @@ export default function TopBar() {
   const remove = async () => {
     if (!state.currentConversation) return;
     try {
-      await fetch(`${API_BASE_URL}/conversations/${state.currentConversation.id}`, {
-        method: 'DELETE',
-        headers: { 'x-api-key': import.meta.env.VITE_API_KEY },
-      });
+      await del(`/conversations/${state.currentConversation.id}`);
       dispatch({
         type: 'SET_CONVERSATIONS',
         conversations: state.conversations.filter((c) => c.id !== state.currentConversation.id),