diff --git a/src/lib/http-timeouts.ts b/src/lib/http-timeouts.ts
new file mode 100644
index 0000000..4866521
--- /dev/null
+++ b/src/lib/http-timeouts.ts
@@ -0,0 +1,24 @@
+/**
+ * Request timeouts for the GitHub / Copilot auth + discovery fetches.
+ *
+ * Production runs on Bun, whose `fetch` has NO default timeout. None of these
+ * calls used to set one, so a half-open connection (network drop, captive
+ * portal, stalled TLS) could hang the operation forever — the token-refresh
+ * self-loop, cold-boot bootstrap, a device-code poll, or a request awaiting a
+ * lazy mint. Each fetch now passes `AbortSignal.timeout(...)`; on timeout it
+ * throws, landing in the caller's EXISTING retry/degrade/continue branch. This
+ * is a bounded guard, not a behavior change.
+ */
+
+/** Copilot token mint + the refresh self-loop (`signed-in → signed-in`). The
+ *  bearer lives ~30 min, refreshed ~25 min in — a 30s ceiling on one attempt
+ *  leaves ample room to retry before expiry. */
+export const COPILOT_TOKEN_TIMEOUT_MS = 30_000
+
+/** GitHub API reads bounded onto the cold-boot / sign-in critical path:
+ *  `/user`, `/copilot_internal/user`, and the device-code request. */
+export const GITHUB_API_TIMEOUT_MS = 15_000
+
+/** One device-code poll attempt. The overall flow is also bounded by the
+ *  device code's own expiry (see pollAccessToken's deadline check). */
+export const DEVICE_POLL_TIMEOUT_MS = 15_000
diff --git a/src/services/github/get-copilot-token.ts b/src/services/github/get-copilot-token.ts
index 257db42..5fd5a12 100644
--- a/src/services/github/get-copilot-token.ts
+++ b/src/services/github/get-copilot-token.ts
@@ -3,6 +3,7 @@ import consola from "consola"
 import { getGitHubApiBaseUrl, githubHeaders } from "~/lib/api-config"
 import { parseCopilotErrorBody } from "~/lib/copilot-error-parser"
 import { CopilotAuthFatalError, HTTPError } from "~/lib/error"
+import { COPILOT_TOKEN_TIMEOUT_MS } from "~/lib/http-timeouts"
 import { state } from "~/lib/state"
 
 export const getCopilotToken = async () => {
@@ -10,6 +11,7 @@ export const getCopilotToken = async () => {
     `${getGitHubApiBaseUrl()}/copilot_internal/v2/token`,
     {
       headers: githubHeaders(state),
+      signal: AbortSignal.timeout(COPILOT_TOKEN_TIMEOUT_MS),
     },
   )
 
diff --git a/src/services/github/get-copilot-usage.ts b/src/services/github/get-copilot-usage.ts
index bf06726..b0f0f9e 100644
--- a/src/services/github/get-copilot-usage.ts
+++ b/src/services/github/get-copilot-usage.ts
@@ -1,5 +1,6 @@
 import { getGitHubApiBaseUrl, githubHeaders } from "~/lib/api-config"
 import { HTTPError } from "~/lib/error"
+import { GITHUB_API_TIMEOUT_MS } from "~/lib/http-timeouts"
 import { state } from "~/lib/state"
 
 export const getCopilotUsage = async (
@@ -15,6 +16,7 @@ export const getCopilotUsage = async (
     `${getGitHubApiBaseUrl()}/copilot_internal/user`,
     {
       headers: githubHeaders(authState),
+      signal: AbortSignal.timeout(GITHUB_API_TIMEOUT_MS),
     },
   )
 
diff --git a/src/services/github/get-device-code.ts b/src/services/github/get-device-code.ts
index ab347eb..4908065 100644
--- a/src/services/github/get-device-code.ts
+++ b/src/services/github/get-device-code.ts
@@ -1,5 +1,6 @@
 import { getOauthAppConfig, getOauthUrls } from "~/lib/api-config"
 import { HTTPError } from "~/lib/error"
+import { GITHUB_API_TIMEOUT_MS } from "~/lib/http-timeouts"
 
 export async function getDeviceCode(): Promise<DeviceCodeResponse> {
   const { clientId, headers, scope } = getOauthAppConfig()
@@ -12,6 +13,7 @@ export async function getDeviceCode(): Promise<DeviceCodeResponse> {
       client_id: clientId,
       scope,
     }),
+    signal: AbortSignal.timeout(GITHUB_API_TIMEOUT_MS),
   })
 
   if (!response.ok) throw new HTTPError("Failed to get device code", response)
diff --git a/src/services/github/get-user.ts b/src/services/github/get-user.ts
index 31793ca..271e55d 100644
--- a/src/services/github/get-user.ts
+++ b/src/services/github/get-user.ts
@@ -1,5 +1,6 @@
 import { getGitHubApiBaseUrl, githubUserHeaders } from "~/lib/api-config"
 import { HTTPError } from "~/lib/error"
+import { GITHUB_API_TIMEOUT_MS } from "~/lib/http-timeouts"
 import { state } from "~/lib/state"
 
 export async function getGitHubUser(githubToken?: string) {
@@ -11,6 +12,7 @@ export async function getGitHubUser(githubToken?: string) {
   const authState = { ...state, githubToken: resolvedGithubToken }
   const response = await fetch(`${getGitHubApiBaseUrl()}/user`, {
     headers: githubUserHeaders(authState),
+    signal: AbortSignal.timeout(GITHUB_API_TIMEOUT_MS),
   })
 
   if (!response.ok) throw new HTTPError("Failed to get GitHub user", response)
diff --git a/src/services/github/poll-access-token.ts b/src/services/github/poll-access-token.ts
index 5bde666..6e56a6e 100644
--- a/src/services/github/poll-access-token.ts
+++ b/src/services/github/poll-access-token.ts
@@ -1,6 +1,7 @@
 import consola from "consola"
 
 import { getOauthAppConfig, getOauthUrls } from "~/lib/api-config"
+import { DEVICE_POLL_TIMEOUT_MS } from "~/lib/http-timeouts"
 import { sleep } from "~/lib/utils"
 
 import type { DeviceCodeResponse } from "./get-device-code"
@@ -34,7 +35,14 @@ export async function pollAccessToken(
   let intervalSeconds = deviceCode.interval + 1
   consola.debug(`Polling access token at ${intervalSeconds}s interval`)
 
+  // Self-expiry guard: bound the whole poll on the device code's own lifetime
+  // so `polling` always terminates into a terminal error even if GitHub never
+  // returns `expired_token` (a hung/misbehaving upstream can't poll forever).
+  const deadlineMs = Date.now() + deviceCode.expires_in * 1000
+
   while (true) {
+    if (Date.now() >= deadlineMs) throw new Error("expired_token")
+
     await sleep(intervalSeconds * 1000)
 
     let response: Response
@@ -42,6 +50,7 @@ export async function pollAccessToken(
       response = await fetch(accessTokenUrl, {
         method: "POST",
         headers,
+        signal: AbortSignal.timeout(DEVICE_POLL_TIMEOUT_MS),
         body: JSON.stringify({
           client_id: clientId,
           device_code: deviceCode.device_code,
diff --git a/tests/poll-access-token.test.ts b/tests/poll-access-token.test.ts
index 9710e74..35fa261 100644
--- a/tests/poll-access-token.test.ts
+++ b/tests/poll-access-token.test.ts
@@ -114,4 +114,16 @@ describe("pollAccessToken (RFC 8628)", () => {
     expect(await pollAccessToken(DEVICE_CODE)).toBe("ghu_late")
     expect(fetchMock).toHaveBeenCalledTimes(2)
   })
+
+  it("self-expires once the device code's lifetime has elapsed, without polling", async () => {
+    // A perpetually-pending upstream would loop forever; the deadline guard
+    // (deviceCode.expires_in) must terminate `polling` on its own. With an
+    // already-elapsed lifetime, it throws before the first fetch.
+    const fetchMock = withResponses([{ error: "authorization_pending" }])
+    await expectRejects(
+      () => pollAccessToken({ ...DEVICE_CODE, expires_in: 0 }),
+      /expired_token/,
+    )
+    expect(fetchMock).toHaveBeenCalledTimes(0)
+  })
 })