diff --git a/packages/app/src/entry.tsx b/packages/app/src/entry.tsx
index 5115f0348ad4..a34be2f9a22b 100644
--- a/packages/app/src/entry.tsx
+++ b/packages/app/src/entry.tsx
@@ -7,7 +7,7 @@ import { type Platform, PlatformProvider } from "@/context/platform"
 import { dict as en } from "@/i18n/en"
 import { dict as zh } from "@/i18n/zh"
 import { handleNotificationClick } from "@/utils/notification-click"
-import { authFromToken } from "@/utils/server"
+import { authFromToken, authFromUrl } from "@/utils/server"
 import pkg from "../package.json"
 import { ServerConnection } from "./context/server"
 
@@ -112,11 +112,14 @@ const getDefaultUrl = () => {
   return getCurrentUrl()
 }
 
-const clearAuthToken = () => {
-  const params = new URLSearchParams(location.search)
-  if (!params.has("auth_token")) return
-  params.delete("auth_token")
-  history.replaceState(null, "", location.pathname + (params.size ? `?${params}` : "") + location.hash)
+const clearStartupAuth = () => {
+  const url = new URL(location.href)
+  const changed = url.searchParams.has("auth_token") || !!url.username || !!url.password
+  if (!changed) return
+  url.searchParams.delete("auth_token")
+  url.username = ""
+  url.password = ""
+  history.replaceState(null, "", url.pathname + url.search + url.hash)
 }
 
 const platform: Platform = {
@@ -154,8 +157,8 @@ if (import.meta.env.VITE_SENTRY_DSN) {
 }
 
 if (root instanceof HTMLElement) {
-  const auth = authFromToken(new URLSearchParams(location.search).get("auth_token"))
-  clearAuthToken()
+  const auth = authFromToken(new URLSearchParams(location.search).get("auth_token")) ?? authFromUrl(location.href)
+  clearStartupAuth()
   const server: ServerConnection.Http = {
     type: "http",
     authToken: !!auth,
diff --git a/packages/app/src/utils/server.test.ts b/packages/app/src/utils/server.test.ts
index 4666b7d6d03c..871bde1aaba0 100644
--- a/packages/app/src/utils/server.test.ts
+++ b/packages/app/src/utils/server.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, test } from "bun:test"
-import { authFromToken, authTokenFromCredentials } from "./server"
+import { authFromToken, authFromUrl, authTokenFromCredentials } from "./server"
 
 describe("authFromToken", () => {
   test("decodes basic auth credentials from auth_token", () => {
@@ -21,3 +21,22 @@ describe("authTokenFromCredentials", () => {
     expect(authTokenFromCredentials({ password: "secret" })).toBe(btoa("opencode:secret"))
   })
 })
+
+describe("authFromUrl", () => {
+  test("decodes basic auth credentials from a URL", () => {
+    expect(authFromUrl("https://kit:secret@example.test")).toEqual({ username: "kit", password: "secret" })
+  })
+
+  test("defaults blank username to opencode", () => {
+    expect(authFromUrl("https://:secret@example.test")).toEqual({ username: "opencode", password: "secret" })
+  })
+
+  test("decodes username-only credentials from a URL", () => {
+    expect(authFromUrl("https://kit@example.test")).toEqual({ username: "kit", password: "" })
+  })
+
+  test("ignores URLs without credentials", () => {
+    expect(authFromUrl("https://example.test")).toBeUndefined()
+    expect(authFromUrl("not a url")).toBeUndefined()
+  })
+})
diff --git a/packages/app/src/utils/server.ts b/packages/app/src/utils/server.ts
index 603784e4d42f..a7957e0c73ad 100644
--- a/packages/app/src/utils/server.ts
+++ b/packages/app/src/utils/server.ts
@@ -8,15 +8,28 @@ export function authTokenFromCredentials(input: { username?: string; password: s
 
 export function authFromToken(token: string | null) {
   const decoded = decode64(token ?? undefined)
-  if (!decoded) return
+  if (!decoded) return undefined
   const separator = decoded.indexOf(":")
-  if (separator === -1) return
+  if (separator === -1) return undefined
   return {
     username: decoded.slice(0, separator) || "opencode",
     password: decoded.slice(separator + 1),
   }
 }
 
+export function authFromUrl(input: string) {
+  try {
+    const url = new URL(input)
+    if (!url.username && url.password === "") return undefined
+    return {
+      username: url.username ? decodeURIComponent(url.username) : "opencode",
+      password: decodeURIComponent(url.password),
+    }
+  } catch {
+    return undefined
+  }
+}
+
 export function createSdkForServer({
   server,
   ...config
@@ -24,7 +37,7 @@ export function createSdkForServer({
   server: ServerConnection.HttpBase
 }) {
   const auth = (() => {
-    if (!server.password) return
+    if (server.password === undefined) return undefined
     return {
       Authorization: `Basic ${authTokenFromCredentials({ username: server.username, password: server.password })}`,
     }
diff --git a/packages/app/src/utils/terminal-websocket-url.test.ts b/packages/app/src/utils/terminal-websocket-url.test.ts
index 5fa1506b1e65..e681b1cba0f2 100644
--- a/packages/app/src/utils/terminal-websocket-url.test.ts
+++ b/packages/app/src/utils/terminal-websocket-url.test.ts
@@ -49,4 +49,32 @@ describe("terminalWebSocketURL", () => {
     expect(url.protocol).toBe("wss:")
     expect(url.searchParams.get("auth_token")).toBe(btoa("opencode:secret"))
   })
+
+  test("uses query auth for username-only startup credentials", () => {
+    const url = terminalWebSocketURL({
+      url: "https://app.example.test",
+      id: "pty_test",
+      directory: "/tmp/project",
+      cursor: 10,
+      sameOrigin: true,
+      username: "kit",
+      password: "",
+      authToken: true,
+    })
+
+    expect(url.searchParams.get("auth_token")).toBe(btoa("kit:"))
+  })
+
+  test("omits query auth when password is undefined", () => {
+    const url = terminalWebSocketURL({
+      url: "https://app.example.test",
+      id: "pty_test",
+      directory: "/tmp/project",
+      cursor: 10,
+      sameOrigin: false,
+      username: "kit",
+    })
+
+    expect(url.searchParams.has("auth_token")).toBe(false)
+  })
 })
diff --git a/packages/app/src/utils/terminal-websocket-url.ts b/packages/app/src/utils/terminal-websocket-url.ts
index 06facdc7d245..107a6cb574bb 100644
--- a/packages/app/src/utils/terminal-websocket-url.ts
+++ b/packages/app/src/utils/terminal-websocket-url.ts
@@ -19,7 +19,8 @@ export function terminalWebSocketURL(input: {
     next.searchParams.set("ticket", input.ticket)
     return next
   }
-  if (input.password && (!input.sameOrigin || input.authToken))
+  // Empty passwords are valid Basic auth credentials.
+  if (input.password !== undefined && (!input.sameOrigin || input.authToken))
     next.searchParams.set(
       "auth_token",
       authTokenFromCredentials({ username: input.username, password: input.password }),