diff --git a/actions/setup/js/codex_harness.cjs b/actions/setup/js/codex_harness.cjs
index a88d4026525..937fbd3ff91 100644
--- a/actions/setup/js/codex_harness.cjs
+++ b/actions/setup/js/codex_harness.cjs
@@ -439,10 +439,11 @@ async function main() {
     }
 
     const nonRetryableGuard = detectNonRetryableHarnessGuard(result.output);
-    if (nonRetryableGuard.aiCreditsExceeded || nonRetryableGuard.awfAPIProxyBlockingRequests) {
+    if (nonRetryableGuard.aiCreditsExceeded || nonRetryableGuard.awfAPIProxyBlockingRequests || nonRetryableGuard.goalAlreadyActive) {
       const reasons = [];
       if (nonRetryableGuard.aiCreditsExceeded) reasons.push("AI credits budget exceeded");
       if (nonRetryableGuard.awfAPIProxyBlockingRequests) reasons.push("AWF API proxy is blocking requests");
+      if (nonRetryableGuard.goalAlreadyActive) reasons.push("goal is already active for this thread (use update_goal when the current goal is complete)");
       log(`attempt ${attempt + 1}: ${reasons.join(" and ")} — not retrying (non-retryable guard condition)`);
       break;
     }
diff --git a/actions/setup/js/codex_harness.test.cjs b/actions/setup/js/codex_harness.test.cjs
index 1b01eb0e7b4..8a00a49e4e4 100644
--- a/actions/setup/js/codex_harness.test.cjs
+++ b/actions/setup/js/codex_harness.test.cjs
@@ -25,6 +25,7 @@ const {
   validateCodexOpenAIBaseURLFromReflect,
   hasNoopInSafeOutputs,
 } = require("./codex_harness.cjs");
+const { detectNonRetryableHarnessGuard } = require("./harness_retry_guard.cjs");
 
 const agentTempDir = "/tmp/gh-aw/agent";
 
@@ -412,6 +413,8 @@ env_key = "OPENAI_API_KEY"
       if (attempt === 0 && isAuthenticationFailedError(result.output)) return false;
       if (isMissingApiKeyError(result.output)) return false;
       if (hasNumerousPermissionDeniedIssues(result.output)) return false;
+      const nonRetryableGuard = detectNonRetryableHarnessGuard(result.output);
+      if (nonRetryableGuard.aiCreditsExceeded || nonRetryableGuard.awfAPIProxyBlockingRequests || nonRetryableGuard.goalAlreadyActive) return false;
       const isTransient = RATE_LIMIT_ERROR_PATTERN.test(result.output) || SERVER_ERROR_PATTERN.test(result.output);
       return attempt < MAX_RETRIES && (result.hasOutput || isTransient);
     }
@@ -461,6 +464,15 @@ env_key = "OPENAI_API_KEY"
       const result = { exitCode: 1, hasOutput: true, output: "permission denied\npermission denied\npermission denied" };
       expect(shouldRetry(result, 0)).toBe(false);
     });
+
+    it("does not retry when codex reports an existing active goal", () => {
+      const result = {
+        exitCode: 1,
+        hasOutput: true,
+        output: "cannot create a new goal because this thread already has a goal; use update_goal only when the existing goal is complete",
+      };
+      expect(shouldRetry(result, 0)).toBe(false);
+    });
   });
 
   describe("noop pre-flight and retry guard", () => {
diff --git a/actions/setup/js/harness_retry_guard.cjs b/actions/setup/js/harness_retry_guard.cjs
index c641f11e198..042c76be2aa 100644
--- a/actions/setup/js/harness_retry_guard.cjs
+++ b/actions/setup/js/harness_retry_guard.cjs
@@ -5,17 +5,19 @@
 const AI_CREDITS_EXCEEDED_PATTERNS = [/\bmax[\s_-]*ai[\s_-]*credits[\s_-]*exceeded\b/i, /\bai[\s_-]*credits[\s_-]*rate[\s_-]*limit[\s_-]*error\b/i, /ai[\s_-]*credits?.*(?:rate[\s-]*limit|limit exceeded|budget exceeded|exceeded)/i];
 
 const AWF_API_PROXY_BLOCKING_REQUESTS_PATTERNS = [/\bawf\b.*\bapi[\s_-]*proxy\b.*\bblocking requests\b/i, /\bapi[\s_-]*proxy\b.*\bblocking requests\b/i, /\bapi[\s_-]*proxy\b.*\bblocked requests?\b/i, /\bDIFC_FILTERED\b/];
+const GOAL_ALREADY_ACTIVE_PATTERNS = [/\bthis thread already has a goal\b[\s\S]*?\buse update_goal\b/i];
 
 /**
  * Detect retry guard conditions that should stop harness retries immediately.
  * @param {unknown} output
- * @returns {{ aiCreditsExceeded: boolean, awfAPIProxyBlockingRequests: boolean }}
+ * @returns {{ aiCreditsExceeded: boolean, awfAPIProxyBlockingRequests: boolean, goalAlreadyActive: boolean }}
  */
 function detectNonRetryableHarnessGuard(output) {
   const safeOutput = typeof output === "string" ? output : "";
   return {
     aiCreditsExceeded: AI_CREDITS_EXCEEDED_PATTERNS.some(pattern => pattern.test(safeOutput)),
     awfAPIProxyBlockingRequests: AWF_API_PROXY_BLOCKING_REQUESTS_PATTERNS.some(pattern => pattern.test(safeOutput)),
+    goalAlreadyActive: GOAL_ALREADY_ACTIVE_PATTERNS.some(pattern => pattern.test(safeOutput)),
   };
 }
 
@@ -24,5 +26,6 @@ if (typeof module !== "undefined" && module.exports) {
     detectNonRetryableHarnessGuard,
     AI_CREDITS_EXCEEDED_PATTERNS,
     AWF_API_PROXY_BLOCKING_REQUESTS_PATTERNS,
+    GOAL_ALREADY_ACTIVE_PATTERNS,
   };
 }
diff --git a/actions/setup/js/harness_retry_guard.test.cjs b/actions/setup/js/harness_retry_guard.test.cjs
index cca3cc71e07..37fd528acb0 100644
--- a/actions/setup/js/harness_retry_guard.test.cjs
+++ b/actions/setup/js/harness_retry_guard.test.cjs
@@ -53,17 +53,42 @@ describe("harness_retry_guard.cjs", () => {
     const result = detectNonRetryableHarnessGuard(null);
     expect(result.aiCreditsExceeded).toBe(false);
     expect(result.awfAPIProxyBlockingRequests).toBe(false);
+    expect(result.goalAlreadyActive).toBe(false);
   });
 
   it("detects both flags when output contains both signals", () => {
     const result = detectNonRetryableHarnessGuard("max_ai_credits_exceeded=true DIFC_FILTERED");
     expect(result.aiCreditsExceeded).toBe(true);
     expect(result.awfAPIProxyBlockingRequests).toBe(true);
+    expect(result.goalAlreadyActive).toBe(false);
   });
 
   it("returns false when output has no guard markers", () => {
     const result = detectNonRetryableHarnessGuard("transient network timeout");
     expect(result.aiCreditsExceeded).toBe(false);
     expect(result.awfAPIProxyBlockingRequests).toBe(false);
+    expect(result.goalAlreadyActive).toBe(false);
+  });
+
+  it("detects goal already active markers", () => {
+    const result = detectNonRetryableHarnessGuard("cannot create a new goal because this thread already has a goal; use update_goal only when the existing goal is complete");
+    expect(result.aiCreditsExceeded).toBe(false);
+    expect(result.awfAPIProxyBlockingRequests).toBe(false);
+    expect(result.goalAlreadyActive).toBe(true);
+  });
+
+  it("detects goal already active markers across newlines", () => {
+    const result = detectNonRetryableHarnessGuard("this thread already has a goal\nuse update_goal to update it");
+    expect(result.goalAlreadyActive).toBe(true);
+  });
+
+  it("does not detect goal active from first phrase alone", () => {
+    const result = detectNonRetryableHarnessGuard("this thread already has a goal");
+    expect(result.goalAlreadyActive).toBe(false);
+  });
+
+  it("detects goal already active when embedded in longer output", () => {
+    const result = detectNonRetryableHarnessGuard("[codex] cannot create a new goal because this thread already has a goal; use update_goal only when the existing goal is complete\nExit code: 1");
+    expect(result.goalAlreadyActive).toBe(true);
   });
 });