feat: introduce backend url environment variable

ref: N25B-352

.env.example

@@ -0,0 +1,2 @@
+# The location of the backend
+VITE_API_BASE_URL=http://localhost:8000

README.md

@@ -28,6 +28,14 @@ npm run dev
 
 It should automatically reload when you save changes.
 
+## Environment
+
+Copy `.env.example` to `.env.local` and adjust values as needed:
+
+```shell
+cp .env.example .env.local
+```
+
 ## Git Hooks
 
 To activate automatic linting, branch name checks and commit message checks, run:

src/components/Logging/useLogs.ts

@@ -5,6 +5,7 @@ import {useCallback, useEffect, useRef, useState} from "react";
 
 import {applyPriorityPredicates, type PriorityFilterPredicate} from "../../utils/priorityFiltering.ts";
 import {cell, type Cell} from "../../utils/cellStore.ts";
+import { API_BASE_URL } from "../../config/api.ts";
 
 type ExtraLevelName = 'LLM' | 'OBSERVATION' | 'ACTION' | 'CHAT';
 
@@ -210,7 +211,7 @@ export function useLogs(filterPredicates: Map<string, LogFilterPredicate>) {
     // Only create one SSE connection for the lifetime of the hook.
     if (sseRef.current) return;
 
-    const es = new EventSource("http://localhost:8000/logs/stream");
+    const es = new EventSource(`${API_BASE_URL}/logs/stream`);
     sseRef.current = es;
 
     es.onmessage = (event) => {

src/config/api.ts

@@ -0,0 +1,11 @@
+declare const __VITE_API_BASE_URL__: string | undefined;
+
+const DEFAULT_API_BASE_URL = "http://localhost:8000";
+
+const rawApiBaseUrl =
+  (typeof __VITE_API_BASE_URL__ !== "undefined" ? __VITE_API_BASE_URL__ : undefined) ??
+  DEFAULT_API_BASE_URL;
+
+export const API_BASE_URL = rawApiBaseUrl.endsWith("/")
+  ? rawApiBaseUrl.slice(0, -1)
+  : rawApiBaseUrl;

src/pages/ConnectedRobots/ConnectedRobots.tsx

@@ -2,6 +2,7 @@
 // University within the Software Project course.
 // © Copyright Utrecht University (Department of Information and Computing Sciences)
 import { useEffect, useState } from 'react'
+import { API_BASE_URL } from '../../config/api.ts';
 
 /**
  * Displays the current connection status of a robot in real time.
@@ -25,7 +26,7 @@ export default function ConnectedRobots() {
   useEffect(() => {
     // Open a Server-Sent Events (SSE) connection to receive live ping updates.
     // We're expecting a stream of data like that looks like this: `data = False` or `data = True`
-    const eventSource = new EventSource("http://localhost:8000/robot/ping_stream");
+    const eventSource = new EventSource(`${API_BASE_URL}/robot/ping_stream`);
     eventSource.onmessage = (event) => {
     
       // Expecting messages in JSON format: `true` or `false`

src/pages/MonitoringPage/MonitoringPageAPI.ts

@@ -2,16 +2,14 @@
 // University within the Software Project course.
 // © Copyright Utrecht University (Department of Information and Computing Sciences)
 import React, { useEffect } from 'react';
-
+import { API_BASE_URL } from '../../config/api.ts';
-const API_BASE = "http://localhost:8000";
-const API_BASE_BP = API_BASE + "/button_pressed"; //UserInterruptAgent endpoint
 
 /**
  * HELPER: Unified sender function
  */
 export const sendAPICall = async (type: string, context: string, endpoint?: string) => {
   try {
-    const response = await fetch(`${API_BASE_BP}${endpoint ?? ""}`, {
+    const response = await fetch(`${API_BASE_URL}/button_pressed${endpoint ?? ""}`, {
       method: "POST",
       headers: { "Content-Type": "application/json" },
       body: JSON.stringify({ type, context }),
@@ -76,7 +74,7 @@ export function useExperimentLogger(onUpdate?: (data: ExperimentStreamData) => v
 
   useEffect(() => {
     console.log("Connecting to Experiment Stream...");
-    const eventSource = new EventSource(`${API_BASE}/experiment_stream`);
+    const eventSource = new EventSource(`${API_BASE_URL}/experiment_stream`);
 
     eventSource.onmessage = (event) => {
       try {
@@ -112,7 +110,7 @@ export function useStatusLogger(onUpdate?: (data: ExperimentStreamData)  => void
   }, [onUpdate]);
 
   useEffect(() => {
-    const eventSource = new EventSource(`${API_BASE}/status_stream`);
+    const eventSource = new EventSource(`${API_BASE_URL}/status_stream`);
     eventSource.onmessage = (event) => {
       try {
         const parsedData = JSON.parse(event.data);
@@ -121,4 +119,4 @@ export function useStatusLogger(onUpdate?: (data: ExperimentStreamData)  => void
     };
     return () => eventSource.close();
   }, []);
-}
+}

src/pages/MonitoringPage/MonitoringPageComponents.tsx

@@ -4,6 +4,7 @@
 import React, { useEffect, useState } from 'react';
 import styles from './MonitoringPage.module.css';
 import { sendAPICall } from './MonitoringPageAPI';
+import { API_BASE_URL } from '../../config/api.ts';
 
 // --- GESTURE COMPONENT ---
 export const GestureControls: React.FC = () => {
@@ -201,7 +202,7 @@ export const RobotConnected = () => {
     useEffect(() => {
       // Open a Server-Sent Events (SSE) connection to receive live ping updates.
       // We're expecting a stream of data like that looks like this: `data = False` or `data = True`
-      const eventSource = new EventSource("http://localhost:8000/robot/ping_stream");
+      const eventSource = new EventSource(`${API_BASE_URL}/robot/ping_stream`);
       eventSource.onmessage = (event) => {
       
         // Expecting messages in JSON format: `true` or `false`
@@ -232,4 +233,4 @@ export const RobotConnected = () => {
     <p className={connected ? styles.connected : styles.disconnected }>{connected ? "● Robot is connected" : "● Robot is disconnected"}</p>
   </div>
   )
-}
+}

src/pages/MonitoringPage/components/ExperimentLogs.tsx

@@ -14,6 +14,7 @@ import formatDuration from "../../../utils/formatDuration.ts";
 import {create} from "zustand";
 import Dialog from "../../../components/Dialog.tsx";
 import delayedResolve from "../../../utils/delayedResolve.ts";
+import { API_BASE_URL } from "../../../config/api.ts";
 
 /**
  * Local Zustand store for logging UI preferences.
@@ -107,7 +108,7 @@ function DownloadScreen({filenames, refresh}: {filenames: string[] | null, refre
 
     return <ol className={`${styles.downloadList} margin-0 padding-h-lg scroll-y`}>
       {filenames!.map((filename) => (
-        <li><a key={filename} href={`http://localhost:8000/api/logs/files/${filename}`} download={filename}>{filename}</a></li>
+        <li><a key={filename} href={`${API_BASE_URL}/api/logs/files/${filename}`} download={filename}>{filename}</a></li>
       ))}
     </ol>;
   })();
@@ -127,7 +128,7 @@ function DownloadButton() {
   const [filenames, setFilenames] = useState<string[] | null>(null);
 
   async function getFiles(): Promise<string[]> {
-    const response = await fetch("http://localhost:8000/api/logs/files");
+    const response = await fetch(`${API_BASE_URL}/api/logs/files`);
     const files = await response.json();
     files.sort();
     return files;
@@ -183,4 +184,4 @@ export default function ExperimentLogs() {
     </div>
     <LogMessages recordCells={filteredLogs} MessageComponent={ExperimentMessage} />
   </aside>;
-}
+}

src/pages/Robot/Robot.tsx

@@ -2,6 +2,7 @@
 // University within the Software Project course.
 // © Copyright Utrecht University (Department of Information and Computing Sciences)
 import { useState, useEffect, useRef } from 'react'
+import { API_BASE_URL } from '../../config/api.ts';
 
 /**
  * Displays a live robot interaction panel with user input, conversation history,
@@ -34,7 +35,7 @@ export default function Robot() {
    */
   const sendMessage = async () => {
     try {
-      const response = await fetch("http://localhost:8000/message", {
+      const response = await fetch(`${API_BASE_URL}/message`, {
         method: "POST",
         headers: {
           "Content-Type": "application/json",
@@ -60,7 +61,7 @@ export default function Robot() {
    * The connection resets whenever `conversationIndex` changes.
    */
   useEffect(() => {
-    const eventSource = new EventSource("http://localhost:8000/sse");
+    const eventSource = new EventSource(`${API_BASE_URL}/sse`);
 
     eventSource.onmessage = (event) => {
       try {

src/pages/VisProgPage/VisProgLogic.ts

@@ -6,6 +6,7 @@ import orderPhaseNodeArray from "../../utils/orderPhaseNodes";
 import useFlowStore from './visualProgrammingUI/VisProgStores';
 import { NodeReduces } from './visualProgrammingUI/NodeRegistry';
 import type { PhaseNode } from "./visualProgrammingUI/nodes/PhaseNode";
+import { API_BASE_URL } from "../../config/api.ts";
 
 /**
  * Reduces the graph into its phases' information and recursively calls their reducing function
@@ -28,7 +29,7 @@ export function runProgram() {
   const program = {phases}
   console.log(JSON.stringify(program, null, 2));
   fetch(
-    "http://localhost:8000/program",
+    `${API_BASE_URL}/program`,
     {
       method: "POST",
       headers: {"Content-Type": "application/json"},
@@ -43,4 +44,4 @@ export function runProgram() {
     useProgramStore.getState().setProgramState(structuredClone(program));
   }).catch(() => console.log("Failed to send program to the backend."));
   console.log(program);
-}
+}

src/vite-env.d.ts

@@ -0,0 +1,11 @@
+/// <reference types="vite/client" />
+
+interface ImportMetaEnv {
+  readonly VITE_API_BASE_URL?: string;
+}
+
+interface ImportMeta {
+  readonly env: ImportMetaEnv;
+}
+
+declare const __VITE_API_BASE_URL__: string | undefined;

test/components/Logging/useLogs.test.tsx

@@ -6,6 +6,7 @@ import "@testing-library/jest-dom";
 import {type LogRecord, useLogs} from "../../../src/components/Logging/useLogs.ts";
 import {type cell, useCell} from "../../../src/utils/cellStore.ts";
 import { StrictMode } from "react";
+import { API_BASE_URL } from "../../../src/config/api.ts";
 
 jest.mock("../../../src/utils/priorityFiltering.ts", () => ({
   applyPriorityPredicates: jest.fn((_log, preds: any[]) =>
@@ -83,7 +84,7 @@ describe("useLogs (unit)", () => {
     );
     const es = (globalThis as any).__es as MockEventSource;
     expect(es).toBeTruthy();
-    expect(es.url).toBe("http://localhost:8000/logs/stream");
+    expect(es.url).toBe(`${API_BASE_URL}/logs/stream`);
 
     unmount();
     expect(es.close).toHaveBeenCalledTimes(1);

test/pages/monitoringPage/MonitoringPageAPI.test.ts

@@ -10,6 +10,7 @@ import {
     useExperimentLogger, 
     useStatusLogger 
 } from '../../../src/pages/MonitoringPage/MonitoringPageAPI';
+import { API_BASE_URL } from '../../../src/config/api.ts';
 
 // --- MOCK EVENT SOURCE SETUP ---
 // This mocks the browser's EventSource so we can manually 'push' messages to our hooks
@@ -72,7 +73,7 @@ describe('MonitoringPageAPI', () => {
       await sendAPICall('test_type', 'test_ctx');
 
       expect(globalThis.fetch).toHaveBeenCalledWith(
-        'http://localhost:8000/button_pressed',
+        `${API_BASE_URL}/button_pressed`,
         expect.objectContaining({
           method: 'POST',
           headers: { 'Content-Type': 'application/json' },
@@ -220,4 +221,4 @@ describe('MonitoringPageAPI', () => {
       expect(consoleSpy).toHaveBeenCalledWith('Status stream error:', expect.any(Error));
     });
   });
-});
+});

test/pages/robot/Robot.test.tsx

@@ -3,6 +3,7 @@
 // © Copyright Utrecht University (Department of Information and Computing Sciences)
 import { render, screen, act, cleanup, fireEvent } from '@testing-library/react';
 import Robot from '../../../src/pages/Robot/Robot';
+import { API_BASE_URL } from '../../../src/config/api.ts';
 
 // Mock EventSource
 const mockInstances: MockEventSource[] = [];
@@ -64,7 +65,7 @@ describe('Robot', () => {
     await act(async () => fireEvent.click(button));
 
     expect(globalThis.fetch).toHaveBeenCalledWith(
-      'http://localhost:8000/message',
+      `${API_BASE_URL}/message`,
       expect.objectContaining({
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
@@ -83,7 +84,7 @@ describe('Robot', () => {
     );
 
     expect(globalThis.fetch).toHaveBeenCalledWith(
-      'http://localhost:8000/message',
+      `${API_BASE_URL}/message`,
       expect.objectContaining({
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },

vite.config.ts

@@ -4,6 +4,9 @@ import react from '@vitejs/plugin-react'
 // https://vite.dev/config/
 export default defineConfig({
   plugins: [react()],
+  define: {
+    __VITE_API_BASE_URL__: "import.meta.env.VITE_API_BASE_URL",
+  },
   css: {
     modules: {
       localsConvention: "camelCase",