diff --git a/src/server.ts b/src/server.ts
index a9f6ae8..dfa15cf 100644
--- a/src/server.ts
+++ b/src/server.ts
@@ -1,10 +1,10 @@
 import { join } from 'path'
-import { unlinkSync } from 'fs'
+import { accessSync, chmodSync, constants, mkdirSync, unlinkSync } from 'fs'
 import type { ServerWebSocket, Subprocess } from 'bun'
 
-const DATA_DIR = process.env.DATA_DIR!
+const DATA_DIR = process.env.DATA_DIR
 const PORT = Number(process.env.PORT) || 3000
-const SOCKET_PATH = join(DATA_DIR, 'tronbyt.sock')
+const SOCKET_PATH = DATA_DIR ? join(DATA_DIR, 'tronbyt.sock') : ''
 const BIN_DIR = join(import.meta.dir, '..', 'bin')
 
 let goProcess: Subprocess | undefined
@@ -107,13 +107,52 @@ async function waitForHealthy(maxAttempts = 60): Promise<boolean> {
   return false
 }
 
+async function downloadBinary(binPath: string): Promise<boolean> {
+  const name = getBinaryName()
+  const url = `https://github.com/tronbyt/server/releases/latest/download/${name}`
+
+  console.log(`Downloading ${name}...`)
+  try {
+    const resp = await fetch(url, { redirect: 'follow' })
+    if (!resp.ok) {
+      console.error(`Download failed: ${resp.status} ${resp.statusText}`)
+      return false
+    }
+
+    mkdirSync(BIN_DIR, { recursive: true })
+    await Bun.write(binPath, resp)
+
+    chmodSync(binPath, 0o755)
+
+    console.log('Download complete')
+    return true
+  } catch (e) {
+    console.error('Download failed:', e)
+    return false
+  }
+}
+
+function validate(): string | undefined {
+  if (!DATA_DIR) return 'DATA_DIR env var is not set — toes should provide this automatically'
+
+  const binPath = join(BIN_DIR, getBinaryName())
+  try {
+    accessSync(binPath, constants.X_OK)
+  } catch {
+    return `Binary not found or not executable: ${binPath}`
+  }
+}
+
 async function spawnGoServer() {
   const binPath = join(BIN_DIR, getBinaryName())
 
   if (!(await Bun.file(binPath).exists())) {
-    console.error(`Binary not found: ${binPath}`)
-    console.error(`Download from https://github.com/tronbyt/server/releases`)
-    console.error(`Expected: ${getBinaryName()}`)
+    if (!(await downloadBinary(binPath))) return
+  }
+
+  const error = validate()
+  if (error) {
+    console.error(`Setup error: ${error}`)
     return
   }
 
@@ -126,7 +165,7 @@ async function spawnGoServer() {
       ...process.env,
       TRONBYT_UNIX_SOCKET: SOCKET_PATH,
       DATA_DIR,
-      DB_DSN: join(DATA_DIR, 'tronbyt.db'),
+      DB_DSN: join(DATA_DIR!, 'tronbyt.db'),
       PRODUCTION: process.env.PRODUCTION ?? 'false',
       SINGLE_USER_AUTO_LOGIN: process.env.SINGLE_USER_AUTO_LOGIN ?? 'true',
       SYSTEM_APPS_AUTO_REFRESH: process.env.SYSTEM_APPS_AUTO_REFRESH ?? 'true',