diff --git a/plugins/codex/scripts/lib/hook-stdin.mjs b/plugins/codex/scripts/lib/hook-stdin.mjs
new file mode 100644
index 000000000..8a3d1041a
--- /dev/null
+++ b/plugins/codex/scripts/lib/hook-stdin.mjs
@@ -0,0 +1,62 @@
+import process from "node:process";
+
+/**
+ * Read Claude Code hook stdin JSON with a hard deadline.
+ *
+ * `fs.readFileSync(0)` blocks until EOF. On Windows, Claude Code sometimes
+ * leaves the write end open after sending the payload, so Stop hooks hang
+ * until the external hook timeout (see #530). Prefer this timed reader.
+ *
+ * @param {number} timeoutMs
+ * @returns {Promise<object>}
+ */
+export function readHookInput(timeoutMs = 5000) {
+  if (process.stdin.isTTY) {
+    return Promise.resolve({});
+  }
+
+  return new Promise((resolve) => {
+    let raw = "";
+    let settled = false;
+
+    const finish = (value) => {
+      if (settled) {
+        return;
+      }
+      settled = true;
+      clearTimeout(timer);
+      process.stdin.removeListener("data", onData);
+      process.stdin.removeListener("end", onEnd);
+      process.stdin.removeListener("error", onError);
+      try {
+        process.stdin.pause();
+      } catch {
+        // ignore
+      }
+
+      const text = String(value ?? "").trim();
+      if (!text) {
+        resolve({});
+        return;
+      }
+      try {
+        resolve(JSON.parse(text));
+      } catch {
+        resolve({});
+      }
+    };
+
+    const timer = setTimeout(() => finish(raw), timeoutMs);
+    const onData = (chunk) => {
+      raw += chunk;
+    };
+    const onEnd = () => finish(raw);
+    const onError = () => finish(raw);
+
+    process.stdin.setEncoding("utf8");
+    process.stdin.on("data", onData);
+    process.stdin.on("end", onEnd);
+    process.stdin.on("error", onError);
+    process.stdin.resume();
+  });
+}
diff --git a/plugins/codex/scripts/stop-review-gate-hook.mjs b/plugins/codex/scripts/stop-review-gate-hook.mjs
index 2346bdcf4..9349bc16c 100644
--- a/plugins/codex/scripts/stop-review-gate-hook.mjs
+++ b/plugins/codex/scripts/stop-review-gate-hook.mjs
@@ -1,6 +1,5 @@
 #!/usr/bin/env node
 
-import fs from "node:fs";
 import process from "node:process";
 import path from "node:path";
 import { spawnSync } from "node:child_process";
@@ -12,19 +11,16 @@ import { getConfig, listJobs } from "./lib/state.mjs";
 import { sortJobsNewestFirst } from "./lib/job-control.mjs";
 import { SESSION_ID_ENV } from "./lib/tracked-jobs.mjs";
 import { resolveWorkspaceRoot } from "./lib/workspace.mjs";
+import { readHookInput } from "./lib/hook-stdin.mjs";
 
 const STOP_REVIEW_TIMEOUT_MS = 15 * 60 * 1000;
 const SCRIPT_DIR = path.dirname(fileURLToPath(import.meta.url));
 const ROOT_DIR = path.resolve(SCRIPT_DIR, "..");
 const STOP_REVIEW_TASK_MARKER = "Run a stop-gate review of the previous Claude turn.";
-
-function readHookInput() {
-  const raw = fs.readFileSync(0, "utf8").trim();
-  if (!raw) {
-    return {};
-  }
-  return JSON.parse(raw);
-}
+// Gate-off path must not wait on Windows stdin EOF (#530). Keep this short.
+const DISABLED_GATE_STDIN_TIMEOUT_MS = 500;
+// Gate-on still needs the payload; bound the wait so a stuck pipe cannot eat the full hook budget.
+const ENABLED_GATE_STDIN_TIMEOUT_MS = 30_000;
 
 function emitDecision(payload) {
   process.stdout.write(`${JSON.stringify(payload)}\n`);
@@ -139,17 +135,34 @@ function runStopReview(cwd, input = {}) {
   }
 }
 
-function main() {
-  const input = readHookInput();
-  const cwd = input.cwd || process.env.CLAUDE_PROJECT_DIR || process.cwd();
-  const workspaceRoot = resolveWorkspaceRoot(cwd);
-  const config = getConfig(workspaceRoot);
-
+function logRunningTaskNote(workspaceRoot, input = {}) {
   const jobs = sortJobsNewestFirst(filterJobsForCurrentSession(listJobs(workspaceRoot), input));
   const runningJob = jobs.find((job) => job.status === "queued" || job.status === "running");
   const runningTaskNote = runningJob
     ? `Codex task ${runningJob.id} is still running. Check /codex:status and use /codex:cancel ${runningJob.id} if you want to stop it before ending the session.`
     : null;
+  return runningTaskNote;
+}
+
+async function main() {
+  // Resolve config from env/cwd first so a disabled gate never waits on stdin EOF (#530).
+  const cwdGuess = process.env.CLAUDE_PROJECT_DIR || process.cwd();
+  const preliminaryRoot = resolveWorkspaceRoot(cwdGuess);
+  const preliminaryConfig = getConfig(preliminaryRoot);
+
+  if (!preliminaryConfig.stopReviewGate) {
+    const input = await readHookInput(DISABLED_GATE_STDIN_TIMEOUT_MS);
+    const cwd = input.cwd || cwdGuess;
+    const workspaceRoot = resolveWorkspaceRoot(cwd);
+    logNote(logRunningTaskNote(workspaceRoot, input));
+    return;
+  }
+
+  const input = await readHookInput(ENABLED_GATE_STDIN_TIMEOUT_MS);
+  const cwd = input.cwd || cwdGuess;
+  const workspaceRoot = resolveWorkspaceRoot(cwd);
+  const config = getConfig(workspaceRoot);
+  const runningTaskNote = logRunningTaskNote(workspaceRoot, input);
 
   if (!config.stopReviewGate) {
     logNote(runningTaskNote);
@@ -176,9 +189,8 @@ function main() {
 }
 
 try {
-  main();
+  await main();
 } catch (error) {
-  const message = error instanceof Error ? error.message : String(error);
-  process.stderr.write(`${message}\n`);
-  process.exitCode = 1;
+  process.stderr.write(`${error?.stack || error}\n`);
+  process.exit(1);
 }
diff --git a/tests/runtime.test.mjs b/tests/runtime.test.mjs
index 8f276835b..4152e2108 100644
--- a/tests/runtime.test.mjs
+++ b/tests/runtime.test.mjs
@@ -2036,6 +2036,62 @@ test("stop hook logs running tasks to stderr without blocking when the review ga
   assert.match(blocked.stderr, /\/codex:cancel task-live/i);
 });
 
+test("stop hook with disabled gate exits quickly when stdin never receives EOF", async () => {
+  const repo = makeTempDir();
+  initGitRepo(repo);
+  fs.writeFileSync(path.join(repo, "README.md"), "hello\n");
+  run("git", ["add", "README.md"], { cwd: repo });
+  run("git", ["commit", "-m", "init"], { cwd: repo });
+
+  const stateDir = resolveStateDir(repo);
+  fs.mkdirSync(stateDir, { recursive: true });
+  fs.writeFileSync(
+    path.join(stateDir, "state.json"),
+    `${JSON.stringify({ version: 1, config: { stopReviewGate: false }, jobs: [] }, null, 2)}\n`,
+    "utf8"
+  );
+
+  const child = spawn(process.execPath, [STOP_HOOK], {
+    cwd: repo,
+    env: {
+      ...process.env,
+      CLAUDE_PROJECT_DIR: repo
+    },
+    stdio: ["pipe", "pipe", "pipe"]
+  });
+
+  // Write a partial payload but never end stdin (Windows EOF hang repro).
+  child.stdin.write(`${JSON.stringify({ cwd: repo })}\n`);
+
+  const started = Date.now();
+  const [status, stdout, stderr] = await new Promise((resolve, reject) => {
+    let out = "";
+    let err = "";
+    const timer = setTimeout(() => {
+      child.kill("SIGTERM");
+      reject(new Error("stop hook hung longer than 3s with review gate disabled"));
+    }, 3000);
+    child.stdout.on("data", (chunk) => {
+      out += chunk;
+    });
+    child.stderr.on("data", (chunk) => {
+      err += chunk;
+    });
+    child.on("error", (error) => {
+      clearTimeout(timer);
+      reject(error);
+    });
+    child.on("close", (code) => {
+      clearTimeout(timer);
+      resolve([code, out, err]);
+    });
+  });
+
+  assert.equal(status, 0, stderr);
+  assert.equal(stdout.trim(), "");
+  assert.ok(Date.now() - started < 2500, `expected fast exit, took ${Date.now() - started}ms`);
+});
+
 test("stop hook allows the stop when the review gate is enabled and the stop-time review task is clean", () => {
   const repo = makeTempDir();
   const binDir = makeTempDir();