diff --git a/tests/unit/codex-custom-tool-image-output-7698.test.ts b/tests/unit/codex-custom-tool-image-output-7698.test.ts
new file mode 100644
index 0000000000..819dd60ba7
--- /dev/null
+++ b/tests/unit/codex-custom-tool-image-output-7698.test.ts
@@ -0,0 +1,35 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { CodexExecutor } from "../../open-sse/executors/codex.ts";
+
+test("Codex passthrough preserves image-view custom tool output input parts (#7698)", () => {
+  const executor = new CodexExecutor();
+  const body = {
+    _nativeCodexPassthrough: true,
+    input: [
+      {
+        type: "message",
+        role: "user",
+        content: [{ type: "input_text", text: "Inspect the image." }],
+      },
+      {
+        type: "custom_tool_call_output",
+        call_id: "call_view_image",
+        output: [
+          { type: "input_text", text: "Script completed\nOutput:\n" },
+          { type: "input_image", image_url: "data:image/png;base64,AA==" },
+        ],
+      },
+    ],
+    stream: false,
+  };
+
+  const result = executor.transformRequest("gpt-5.6", body, false, {
+    requestEndpointPath: "/responses",
+  });
+  const toolOutput = result.input.find((item) => item.type === "custom_tool_call_output");
+
+  assert.deepEqual(toolOutput, body.input[1]);
+  assert.equal(JSON.stringify(toolOutput).includes('"type":"output_text"'), false);
+});