diff --git a/src/__tests__/sites-crud.test.ts b/src/__tests__/sites-crud.test.ts
new file mode 100644
index 0000000..6d61d16
--- /dev/null
+++ b/src/__tests__/sites-crud.test.ts
@@ -0,0 +1,156 @@
+import { describe, test, expect, vi, beforeEach } from "vitest"
+
+// Mock next/cache
+vi.mock("next/cache", () => ({
+  revalidatePath: vi.fn(),
+}))
+
+// Mock next/navigation
+const mockRedirect = vi.fn()
+vi.mock("next/navigation", () => ({
+  redirect: (url: string) => {
+    mockRedirect(url)
+    throw new Error(`NEXT_REDIRECT:${url}`)
+  },
+}))
+
+// Mock Supabase server client
+const mockFrom = vi.fn()
+const mockGetUser = vi.fn()
+
+vi.mock("@/lib/supabase/server", () => ({
+  createClient: () =>
+    Promise.resolve({
+      from: mockFrom,
+      auth: { getUser: mockGetUser },
+    }),
+}))
+
+import { addSite, editSite, deleteSite } from "@/app/sites/actions"
+
+describe("addSite action", () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  test("redirects unauthenticated users to login", async () => {
+    mockGetUser.mockResolvedValue({ data: { user: null } })
+
+    const formData = new FormData()
+    formData.set("name", "Test Site")
+    formData.set("url", "https://example.com")
+
+    await expect(addSite(formData)).rejects.toThrow("NEXT_REDIRECT:/login")
+  })
+
+  test("inserts site for authenticated users", async () => {
+    mockGetUser.mockResolvedValue({
+      data: { user: { id: "user-1" } },
+    })
+
+    const mockInsert = vi.fn().mockReturnValue({ error: null })
+    mockFrom.mockReturnValue({ insert: mockInsert })
+
+    const formData = new FormData()
+    formData.set("name", "Test Site")
+    formData.set("url", "https://example.com")
+
+    await addSite(formData)
+    expect(mockFrom).toHaveBeenCalledWith("sites")
+    expect(mockInsert).toHaveBeenCalledWith({
+      name: "Test Site",
+      url: "https://example.com",
+    })
+  })
+
+  test("does nothing if name or url is empty", async () => {
+    mockGetUser.mockResolvedValue({
+      data: { user: { id: "user-1" } },
+    })
+
+    const formData = new FormData()
+    formData.set("name", "Test Site")
+    // url is missing
+
+    await addSite(formData)
+    expect(mockFrom).not.toHaveBeenCalled()
+  })
+})
+
+describe("editSite action", () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  test("redirects unauthenticated users to login", async () => {
+    mockGetUser.mockResolvedValue({ data: { user: null } })
+
+    const formData = new FormData()
+    formData.set("name", "Updated")
+    formData.set("url", "https://example.com")
+
+    await expect(editSite("site-1", formData)).rejects.toThrow(
+      "NEXT_REDIRECT:/login"
+    )
+  })
+
+  test("updates site for authenticated users", async () => {
+    mockGetUser.mockResolvedValue({
+      data: { user: { id: "user-1" } },
+    })
+
+    const mockEq = vi.fn().mockReturnValue({ error: null })
+    const mockUpdate = vi.fn().mockReturnValue({ eq: mockEq })
+    mockFrom.mockReturnValue({ update: mockUpdate })
+
+    const formData = new FormData()
+    formData.set("name", "Updated Site")
+    formData.set("url", "https://updated.com")
+
+    await editSite("site-1", formData)
+    expect(mockFrom).toHaveBeenCalledWith("sites")
+    expect(mockUpdate).toHaveBeenCalledWith({
+      name: "Updated Site",
+      url: "https://updated.com",
+    })
+    expect(mockEq).toHaveBeenCalledWith("id", "site-1")
+  })
+
+  test("does nothing if name or url is empty", async () => {
+    mockGetUser.mockResolvedValue({
+      data: { user: { id: "user-1" } },
+    })
+
+    const formData = new FormData()
+    // both fields empty
+
+    await editSite("site-1", formData)
+    expect(mockFrom).not.toHaveBeenCalled()
+  })
+})
+
+describe("deleteSite action", () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  test("redirects unauthenticated users to login", async () => {
+    mockGetUser.mockResolvedValue({ data: { user: null } })
+
+    await expect(deleteSite("site-1")).rejects.toThrow("NEXT_REDIRECT:/login")
+  })
+
+  test("deletes site for authenticated users", async () => {
+    mockGetUser.mockResolvedValue({
+      data: { user: { id: "user-1" } },
+    })
+
+    const mockEq = vi.fn().mockReturnValue({ error: null })
+    const mockDelete = vi.fn().mockReturnValue({ eq: mockEq })
+    mockFrom.mockReturnValue({ delete: mockDelete })
+
+    await deleteSite("site-1")
+    expect(mockFrom).toHaveBeenCalledWith("sites")
+    expect(mockEq).toHaveBeenCalledWith("id", "site-1")
+  })
+})
diff --git a/src/app/page.tsx b/src/app/page.tsx
index 9615789..e6b3aa0 100644
--- a/src/app/page.tsx
+++ b/src/app/page.tsx
@@ -2,6 +2,8 @@ import Link from "next/link"
 import { createClient } from "@/lib/supabase/server"
 import type { Site, Check, Incident } from "@/lib/supabase/types"
 import { formatTimeAgo, formatDuration } from "@/lib/format"
+import AddSiteCard from "@/components/AddSiteCard"
+import EditSiteButton from "@/components/EditSiteButton"
 
 export const revalidate = 0
 
@@ -37,14 +39,19 @@ async function getStatusData() {
     })
   }
 
+  const {
+    data: { user },
+  } = await supabase.auth.getUser()
+
   return {
     sites: sitesWithChecks,
     incidents: (openIncidents ?? []) as IncidentWithSite[],
+    isAdmin: !!user,
   }
 }
 
 export default async function StatusPage() {
-  const { sites, incidents } = await getStatusData()
+  const { sites, incidents, isAdmin } = await getStatusData()
 
   return (
     <main
@@ -118,58 +125,74 @@ export default async function StatusPage() {
           Sites
         </h2>
 
-        {sites.length === 0 ? (
+        {sites.length === 0 && !isAdmin ? (
           <p className="text-sm" style={{ color: "#5C5C5C" }}>
             No sites are being monitored yet.
           </p>
         ) : (
           <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-3">
             {sites.map((site) => (
-              <Link
+              <div
                 key={site.id}
-                href={`/sites/${site.id}`}
-                className="block no-underline"
+                className="group relative"
                 style={{
                   backgroundColor: "#FFFFFF",
                   border: "1px solid #E8E4DF",
                   borderRadius: "4px",
                   padding: "16px 18px",
-                  color: "inherit",
                 }}
               >
-                <div className="flex items-center gap-2.5">
-                  <span
-                    className="w-2 h-2 rounded-full shrink-0"
-                    style={{
-                      backgroundColor:
-                        site.lastCheck?.status === "failure"
-                          ? "#C4453C"
-                          : "#5A8A5A",
-                    }}
-                  />
-                  <span
-                    className="text-sm font-bold truncate"
-                    style={{ color: "#1A1A1A" }}
-                  >
-                    {site.name}
-                  </span>
-                </div>
-                <div
-                  className="mt-1.5 text-xs truncate"
-                  style={{ color: "#5C5C5C" }}
-                >
-                  {site.url}
-                </div>
-                <div
-                  className="mt-2 text-[11px]"
-                  style={{ color: "#8A8A8A", letterSpacing: "0.01em" }}
+                <Link
+                  href={`/sites/${site.id}`}
+                  className="block no-underline"
+                  style={{ color: "inherit" }}
                 >
-                  {site.lastCheck
-                    ? `Checked ${formatTimeAgo(site.lastCheck.checked_at)}`
-                    : "No checks yet"}
-                </div>
-              </Link>
+                  <div className="flex items-center justify-between gap-2">
+                    <div className="flex items-center gap-2.5 min-w-0">
+                      <span
+                        className="w-2 h-2 rounded-full shrink-0"
+                        style={{
+                          backgroundColor:
+                            site.lastCheck?.status === "failure"
+                              ? "#C4453C"
+                              : "#5A8A5A",
+                        }}
+                      />
+                      <span
+                        className="text-sm font-bold truncate"
+                        style={{ color: "#1A1A1A" }}
+                      >
+                        {site.name}
+                      </span>
+                    </div>
+                  </div>
+                  <div
+                    className="mt-1.5 text-xs truncate"
+                    style={{ color: "#5C5C5C" }}
+                  >
+                    {site.url}
+                  </div>
+                  <div
+                    className="mt-2 text-[11px]"
+                    style={{ color: "#8A8A8A", letterSpacing: "0.01em" }}
+                  >
+                    {site.lastCheck
+                      ? `Checked ${formatTimeAgo(site.lastCheck.checked_at)}`
+                      : "No checks yet"}
+                  </div>
+                </Link>
+                {isAdmin && (
+                  <div className="absolute top-3 right-3">
+                    <EditSiteButton
+                      siteId={site.id}
+                      name={site.name}
+                      url={site.url}
+                    />
+                  </div>
+                )}
+              </div>
             ))}
+            {isAdmin && <AddSiteCard />}
           </div>
         )}
       </section>
diff --git a/src/app/sites/actions.ts b/src/app/sites/actions.ts
new file mode 100644
index 0000000..c44080c
--- /dev/null
+++ b/src/app/sites/actions.ts
@@ -0,0 +1,52 @@
+"use server"
+
+import { revalidatePath } from "next/cache"
+import { redirect } from "next/navigation"
+import { createClient } from "@/lib/supabase/server"
+
+export async function addSite(formData: FormData) {
+  const supabase = await createClient()
+  const {
+    data: { user },
+  } = await supabase.auth.getUser()
+
+  if (!user) redirect("/login")
+
+  const name = (formData.get("name") as string)?.trim()
+  const url = (formData.get("url") as string)?.trim()
+
+  if (!name || !url) return
+
+  await supabase.from("sites").insert({ name, url })
+  revalidatePath("/")
+}
+
+export async function editSite(siteId: string, formData: FormData) {
+  const supabase = await createClient()
+  const {
+    data: { user },
+  } = await supabase.auth.getUser()
+
+  if (!user) redirect("/login")
+
+  const name = (formData.get("name") as string)?.trim()
+  const url = (formData.get("url") as string)?.trim()
+
+  if (!name || !url) return
+
+  await supabase.from("sites").update({ name, url }).eq("id", siteId)
+  revalidatePath("/")
+  revalidatePath(`/sites/${siteId}`)
+}
+
+export async function deleteSite(siteId: string) {
+  const supabase = await createClient()
+  const {
+    data: { user },
+  } = await supabase.auth.getUser()
+
+  if (!user) redirect("/login")
+
+  await supabase.from("sites").delete().eq("id", siteId)
+  revalidatePath("/")
+}
diff --git a/src/components/AddSiteCard.tsx b/src/components/AddSiteCard.tsx
new file mode 100644
index 0000000..348cfb4
--- /dev/null
+++ b/src/components/AddSiteCard.tsx
@@ -0,0 +1,104 @@
+"use client"
+
+import { useState } from "react"
+import { addSite } from "@/app/sites/actions"
+
+export default function AddSiteCard() {
+  const [isOpen, setIsOpen] = useState(false)
+
+  if (!isOpen) {
+    return (
+      <button
+        onClick={() => setIsOpen(true)}
+        className="flex items-center justify-center flex-col gap-1.5 rounded cursor-pointer"
+        style={{
+          background: "transparent",
+          border: "1.5px dashed #D4CFC9",
+          padding: "24px 18px",
+          color: "#8A8A8A",
+          minHeight: "108px",
+          transition: "border-color 0.15s, color 0.15s",
+        }}
+      >
+        <svg
+          width="20"
+          height="20"
+          viewBox="0 0 16 16"
+          fill="none"
+          stroke="currentColor"
+          strokeWidth="1.5"
+          strokeLinecap="round"
+        >
+          <path d="M8 3v10M3 8h10" />
+        </svg>
+        <span className="text-[13px] font-medium">Add site</span>
+      </button>
+    )
+  }
+
+  return (
+    <div
+      className="rounded"
+      style={{
+        backgroundColor: "#FFFFFF",
+        border: "1px solid #E8E4DF",
+        padding: "16px 18px",
+      }}
+    >
+      <form
+        action={async (formData) => {
+          await addSite(formData)
+          setIsOpen(false)
+        }}
+        className="flex flex-col gap-2"
+      >
+        <input
+          type="text"
+          name="name"
+          placeholder="Site name"
+          required
+          autoFocus
+          className="text-sm px-3 py-2 rounded outline-none"
+          style={{
+            border: "1px solid #E8E4DF",
+            backgroundColor: "#FFFFFF",
+            color: "#1A1A1A",
+          }}
+        />
+        <input
+          type="url"
+          name="url"
+          placeholder="https://example.com"
+          required
+          className="text-sm px-3 py-2 rounded outline-none"
+          style={{
+            border: "1px solid #E8E4DF",
+            backgroundColor: "#FFFFFF",
+            color: "#1A1A1A",
+          }}
+        />
+        <div className="flex gap-2 mt-1">
+          <button
+            type="submit"
+            className="text-sm font-medium px-3 py-1.5 rounded cursor-pointer text-white"
+            style={{ backgroundColor: "#2C2C2C" }}
+          >
+            Add
+          </button>
+          <button
+            type="button"
+            onClick={() => setIsOpen(false)}
+            className="text-sm px-3 py-1.5 rounded cursor-pointer"
+            style={{
+              backgroundColor: "transparent",
+              color: "#5C5C5C",
+              border: "1px solid #E8E4DF",
+            }}
+          >
+            Cancel
+          </button>
+        </div>
+      </form>
+    </div>
+  )
+}
diff --git a/src/components/EditSiteButton.tsx b/src/components/EditSiteButton.tsx
new file mode 100644
index 0000000..f042ecd
--- /dev/null
+++ b/src/components/EditSiteButton.tsx
@@ -0,0 +1,122 @@
+"use client"
+
+import { useState } from "react"
+import { editSite, deleteSite } from "@/app/sites/actions"
+
+export default function EditSiteButton({
+  siteId,
+  name,
+  url,
+}: {
+  siteId: string
+  name: string
+  url: string
+}) {
+  const [isEditing, setIsEditing] = useState(false)
+
+  if (!isEditing) {
+    return (
+      <button
+        onClick={() => setIsEditing(true)}
+        className="flex items-center justify-center rounded cursor-pointer opacity-0 group-hover:opacity-100 transition-opacity flex-shrink-0"
+        style={{
+          width: "28px",
+          height: "28px",
+          color: "#5C5C5C",
+          background: "transparent",
+          border: "none",
+        }}
+        title="Edit site"
+      >
+        <svg
+          width="14"
+          height="14"
+          viewBox="0 0 16 16"
+          fill="none"
+          stroke="currentColor"
+          strokeWidth="1.5"
+          strokeLinecap="round"
+          strokeLinejoin="round"
+        >
+          <path d="M11.5 1.5l3 3-9 9H2.5v-3z" />
+          <path d="M10 3l3 3" />
+        </svg>
+      </button>
+    )
+  }
+
+  return (
+    <div
+      className="absolute inset-0 rounded z-10"
+      style={{
+        backgroundColor: "#FFFFFF",
+        border: "1px solid #E8E4DF",
+        padding: "16px 18px",
+      }}
+    >
+      <form
+        action={editSite.bind(null, siteId)}
+        className="flex flex-col gap-2"
+      >
+        <input
+          type="text"
+          name="name"
+          defaultValue={name}
+          required
+          autoFocus
+          className="text-sm px-3 py-2 rounded outline-none"
+          style={{
+            border: "1px solid #E8E4DF",
+            backgroundColor: "#FFFFFF",
+            color: "#1A1A1A",
+          }}
+        />
+        <input
+          type="url"
+          name="url"
+          defaultValue={url}
+          required
+          className="text-sm px-3 py-2 rounded outline-none"
+          style={{
+            border: "1px solid #E8E4DF",
+            backgroundColor: "#FFFFFF",
+            color: "#1A1A1A",
+          }}
+        />
+        <div className="flex gap-2 mt-1">
+          <button
+            type="submit"
+            className="text-sm font-medium px-3 py-1.5 rounded cursor-pointer text-white"
+            style={{ backgroundColor: "#2C2C2C" }}
+          >
+            Save
+          </button>
+          <button
+            type="button"
+            onClick={() => setIsEditing(false)}
+            className="text-sm px-3 py-1.5 rounded cursor-pointer"
+            style={{
+              backgroundColor: "transparent",
+              color: "#5C5C5C",
+              border: "1px solid #E8E4DF",
+            }}
+          >
+            Cancel
+          </button>
+          <button
+            type="button"
+            onClick={() => deleteSite(siteId)}
+            className="text-sm px-3 py-1.5 rounded cursor-pointer ml-auto"
+            style={{
+              backgroundColor: "transparent",
+              color: "#C4453C",
+              border: "1px solid #E8E4DF",
+            }}
+          >
+            Delete
+          </button>
+        </div>
+      </form>
+    </div>
+  )
+}