Feature/frontend api stream and docs

frontend/chat-ui/src/api.js

@@ -1,22 +1,30 @@
 export const API_BASE_URL = import.meta.env.VITE_API_BASE_URL || '';
 const API_KEY = import.meta.env.VITE_API_KEY || '';
 
+function buildUrl(path) {
+  const clean = path.startsWith('/') ? path : `/${path}`;
+  return API_BASE_URL ? `${API_BASE_URL.replace(/\/$/, '')}${clean}` : clean;
+}
+
 async function request(method, path, body) {
-  const headers = { 'x-api-key': API_KEY };
+  const url = buildUrl(path);
+  const headers = {};
+  if (API_KEY) headers['x-api-key'] = API_KEY;
   const options = { method, headers };
   if (body !== undefined) {
     headers['Content-Type'] = 'application/json';
     options.body = JSON.stringify(body);
   }
 
-  const res = await fetch(`${API_BASE_URL}${path}`, options);
+  const res = await fetch(url, options);
   const text = await res.text();
   let data = null;
   if (text) {
     try {
       data = JSON.parse(text);
     } catch (err) {
-      throw err;
+      // non-JSON response; preserve text in data
+      data = text;
     }
   }
   if (!res.ok) {
@@ -33,4 +41,15 @@ export const post = (path, body) => request('POST', path, body);
 export const put = (path, body) => request('PUT', path, body);
 export const del = (path) => request('DELETE', path);
 
-export default { get, post, put, del };
+// Create an EventSource for SSE. Many servers don't accept custom headers for SSE,
+// so we append the API key as a query parameter named `x-api-key` when present.
+export function stream(path) {
+  let url = buildUrl(path);
+  if (API_KEY) {
+    const hasQuery = url.includes('?');
+    url = `${url}${hasQuery ? '&' : '?'}x-api-key=${encodeURIComponent(API_KEY)}`;
+  }
+  return new EventSource(url);
+}
+
+export default { get, post, put, del, stream };