diff --git a/CLAUDE.md b/CLAUDE.md
index d75a7a45..9a7edc28 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -20,9 +20,11 @@ bun run eval:compare # compare two eval runs (auto-picks most recent)
 bun run eval:summary # aggregate stats across all eval runs
 ```
 
-`test:evals` requires `ANTHROPIC_API_KEY`. E2E tests stream progress in real-time
-(tool-by-tool via `--output-format stream-json --verbose`). Results are persisted
-to `~/.gstack-dev/evals/` with auto-comparison against the previous run.
+`test:evals` requires `ANTHROPIC_API_KEY`. Codex E2E tests (`test/codex-e2e.test.ts`)
+use Codex's own auth from `~/.codex/` config — no `OPENAI_API_KEY` env var needed.
+E2E tests stream progress in real-time (tool-by-tool via `--output-format stream-json
+--verbose`). Results are persisted to `~/.gstack-dev/evals/` with auto-comparison
+against the previous run.
 
 **Diff-based test selection:** `test:evals` and `test:e2e` auto-select tests based
 on `git diff` against the base branch. Each test declares its file dependencies in
diff --git a/test/codex-e2e.test.ts b/test/codex-e2e.test.ts
index 91fc7abc..99fc46bb 100644
--- a/test/codex-e2e.test.ts
+++ b/test/codex-e2e.test.ts
@@ -7,7 +7,7 @@
  *
  * Prerequisites:
  * - `codex` binary installed (npm install -g @openai/codex)
- * - OPENAI_API_KEY env var set
+ * - Codex authenticated via ~/.codex/ config (no OPENAI_API_KEY env var needed)
  * - EVALS=1 env var set (same gate as Claude E2E tests)
  *
  * Skips gracefully when prerequisites are not met.
@@ -34,11 +34,11 @@ const CODEX_AVAILABLE = (() => {
   } catch { return false; }
 })();
 
-const HAS_API_KEY = !!process.env.OPENAI_API_KEY;
 const evalsEnabled = !!process.env.EVALS;
 
-// Skip all tests if codex is not available, API key is not set, or EVALS is not set
-const SKIP = !CODEX_AVAILABLE || !HAS_API_KEY || !evalsEnabled;
+// Skip all tests if codex is not available or EVALS is not set.
+// Note: Codex uses its own auth from ~/.codex/ config — no OPENAI_API_KEY env var needed.
+const SKIP = !CODEX_AVAILABLE || !evalsEnabled;
 
 const describeCodex = SKIP ? describe.skip : describe;
 
@@ -47,8 +47,6 @@ if (!evalsEnabled) {
   // Silent — same as Claude E2E tests, EVALS=1 required
 } else if (!CODEX_AVAILABLE) {
   process.stderr.write('\nCodex E2E: SKIPPED — codex binary not found (install: npm i -g @openai/codex)\n');
-} else if (!HAS_API_KEY) {
-  process.stderr.write('\nCodex E2E: SKIPPED — OPENAI_API_KEY not set\n');
 }
 
 // --- Diff-based test selection ---
@@ -155,7 +153,7 @@ describeCodex('Codex E2E', () => {
     const result = await runCodexSkill({
       skillDir,
       prompt: 'Run the gstack-review skill on this repository. Review the current branch diff and report your findings.',
-      timeoutMs: 300_000,
+      timeoutMs: 540_000,
       cwd: ROOT,
       skillName: 'gstack-review',
     });
@@ -183,5 +181,5 @@ describeCodex('Codex E2E', () => {
       outputLower.includes('p1') ||
       outputLower.includes('p2');
     expect(hasReviewContent).toBe(true);
-  }, 360_000);
+  }, 600_000);
 });
diff --git a/test/helpers/codex-session-runner.ts b/test/helpers/codex-session-runner.ts
index c4d0256f..77b45020 100644
--- a/test/helpers/codex-session-runner.ts
+++ b/test/helpers/codex-session-runner.ts
@@ -164,10 +164,30 @@ export async function runCodexSkill(opts: {
 
   // Set up temp HOME with skill installed
   const tempHome = fs.mkdtempSync(path.join(os.tmpdir(), 'codex-e2e-'));
+  const realHome = os.homedir();
 
   try {
     installSkillToTempHome(skillDir, name, tempHome);
 
+    // Symlink real Codex auth config so codex can authenticate from temp HOME.
+    // Codex stores auth in ~/.codex/ — we need the config but not the skills
+    // (we install our own test skills above).
+    const realCodexConfig = path.join(realHome, '.codex');
+    const tempCodexDir = path.join(tempHome, '.codex');
+    if (fs.existsSync(realCodexConfig)) {
+      // Copy auth-related files from real ~/.codex/ into temp ~/.codex/
+      // (skills/ is already set up by installSkillToTempHome)
+      const entries = fs.readdirSync(realCodexConfig);
+      for (const entry of entries) {
+        if (entry === 'skills') continue; // don't clobber our test skills
+        const src = path.join(realCodexConfig, entry);
+        const dst = path.join(tempCodexDir, entry);
+        if (!fs.existsSync(dst)) {
+          fs.cpSync(src, dst, { recursive: true });
+        }
+      }
+    }
+
     // Build codex exec command
     const args = ['exec', prompt, '--json', '-s', sandbox];