diff --git a/changelog.d/fixes/6805-strip-include-compact-responses.md b/changelog.d/fixes/6805-strip-include-compact-responses.md
new file mode 100644
index 00000000000..6c46a717a42
--- /dev/null
+++ b/changelog.d/fixes/6805-strip-include-compact-responses.md
@@ -0,0 +1 @@
+- **fix(codex): strip include from compact responses requests** (#6805 — thanks @yinaoxiong).
diff --git a/open-sse/executors/codex.ts b/open-sse/executors/codex.ts
index 6bca470eb55..ceaa8bda692 100644
--- a/open-sse/executors/codex.ts
+++ b/open-sse/executors/codex.ts
@@ -894,7 +894,9 @@ export class CodexExecutor extends BaseExecutor {
       headers["chatgpt-account-id"] = workspaceId;
     }
     const clientIdentity = credentials?.providerSpecificData?.codexClientIdentity as
-      CodexClientIdentity | null | undefined;
+      | CodexClientIdentity
+      | null
+      | undefined;
 
     // Originator header — identifies the client type to the Codex backend.
     // Ref: openai/codex login/src/auth/default_client.rs DEFAULT_ORIGINATOR = "codex_cli_rs"
@@ -1001,6 +1003,7 @@ export class CodexExecutor extends BaseExecutor {
       delete body.stream;
       delete body.stream_options;
       delete body.client_metadata;
+      delete body.include;
     } else {
       body.stream = true;
     }
@@ -1174,6 +1177,9 @@ export class CodexExecutor extends BaseExecutor {
       };
     }
     ensureCodexReasoningSummary(body);
+    if (isCompactRequest) {
+      delete body.include;
+    }
     delete body.reasoning_effort;
 
     // Remove unsupported token limit parameters BEFORE the passthrough return.
@@ -1214,7 +1220,9 @@ export class CodexExecutor extends BaseExecutor {
       applyCodexClientMetadata(
         body,
         credentials?.providerSpecificData?.codexClientIdentity as
-          CodexClientIdentity | null | undefined
+          | CodexClientIdentity
+          | null
+          | undefined
       );
     }
 
diff --git a/tests/unit/codex-compact-strip-include-6805.test.ts b/tests/unit/codex-compact-strip-include-6805.test.ts
new file mode 100644
index 00000000000..91e0d080c3f
--- /dev/null
+++ b/tests/unit/codex-compact-strip-include-6805.test.ts
@@ -0,0 +1,28 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { CodexExecutor } from "../../open-sse/executors/codex.ts";
+
+// #6805: compact Codex requests must not forward `include` (e.g.
+// "reasoning.encrypted_content") — the compact endpoint rejects it. Kept in a
+// standalone file so the frozen executor-codex.test.ts does not grow past its cap.
+test("CodexExecutor.transformRequest strips include from compact requests (#6805)", () => {
+  const executor = new CodexExecutor();
+  const result = executor.transformRequest(
+    "gpt-5.3-codex",
+    {
+      _nativeCodexPassthrough: true,
+      include: ["reasoning.encrypted_content"],
+      instructions: "keep this",
+      stream: false,
+    },
+    false,
+    {
+      requestEndpointPath: "/responses/compact",
+      providerSpecificData: { requestDefaults: { serviceTier: "priority" } },
+    }
+  );
+  assert.equal(result.include, undefined);
+  assert.equal(result._nativeCodexPassthrough, undefined);
+  assert.equal(result.instructions, "keep this");
+});