diff --git a/cshare-app/src/lib/api.js b/cshare-app/src/lib/api.js
new file mode 100644
index 0000000..3f95382
--- /dev/null
+++ b/cshare-app/src/lib/api.js
@@ -0,0 +1,97 @@
+const API_BASE = (
+  import.meta.env.VITE_API_BASE_URL ||
+  (import.meta.env.DEV ? 'http://localhost:4001' : window.location.origin)
+).replace(/\/$/, '');
+
+async function request(path, options = {}) {
+  const response = await fetch(`${API_BASE}${path}`, {
+    credentials: 'include',
+    headers: {
+      ...(options.body instanceof FormData ? {} : { 'Content-Type': 'application/json' }),
+      ...options.headers,
+    },
+    ...options,
+  });
+
+  if (!response.ok) {
+    const payload = await response.json().catch(() => ({}));
+    throw new Error(payload.error || `Request failed with ${response.status}`);
+  }
+
+  if (response.status === 204) return null;
+  return response.json();
+}
+
+export function uploadFile(file, { onProgress } = {}) {
+  return new Promise((resolve, reject) => {
+    const xhr = new XMLHttpRequest();
+    const form = new FormData();
+    form.append('file', file);
+
+    xhr.open('POST', `${API_BASE}/api/v1/files/upload`);
+    xhr.withCredentials = true;
+
+    xhr.upload.onprogress = (event) => {
+      if (event.lengthComputable && onProgress) {
+        onProgress(Math.round((event.loaded / event.total) * 100));
+      }
+    };
+
+    xhr.onload = () => {
+      if (xhr.status >= 200 && xhr.status < 300) {
+        resolve(JSON.parse(xhr.responseText));
+        return;
+      }
+      try {
+        reject(new Error(JSON.parse(xhr.responseText).error || 'Upload failed'));
+      } catch {
+        reject(new Error('Upload failed'));
+      }
+    };
+
+    xhr.onerror = () => reject(new Error('Could not reach upload service'));
+    xhr.send(form);
+  });
+}
+
+export async function listFiles() {
+  const payload = await request('/api/v1/files');
+  return payload.data;
+}
+
+export async function deleteFile(id) {
+  await request(`/api/v1/files/${id}`, { method: 'DELETE' });
+}
+
+export async function getDashboardStats() {
+  const payload = await request('/api/v1/dashboard/stats');
+  return payload.data;
+}
+
+export async function getDashboardActivity() {
+  const payload = await request('/api/v1/dashboard/activity');
+  return payload.data;
+}
+
+export async function getDashboardStorage() {
+  const payload = await request('/api/v1/dashboard/storage');
+  return payload.data;
+}
+
+export async function getFileAnalytics(fileId) {
+  const payload = await request(`/api/v1/files/${fileId}/analytics`);
+  return payload.data;
+}
+
+export async function resolveLink(linkId) {
+  const payload = await request(`/api/v1/links/${linkId}`);
+  return payload.data;
+}
+
+export function downloadUrl(linkId) {
+  return `${API_BASE}/api/v1/links/${linkId}/download`;
+}
+
+export function previewUrl(linkId) {
+  return `${API_BASE}/api/v1/links/${linkId}/preview`;
+}