fix(responses): gracefully handle code-mode view_image calls via unified exec

src/responses/code-mode-helper-compat.ts

@@ -54,6 +54,16 @@ export function compileCodeModeHelperInput(argumentsText: unknown, toolName: str
   if (toolName === "write_stdin") {
     return `const result = await tools.write_stdin(${JSON.stringify(args)});\ntext(result);`;
   }
+  if (toolName === "view_image") {
+    let target = "";
+    if (isPlainObject(args)) {
+      if (typeof args.path === "string") target = ` for ${JSON.stringify(args.path)}`;
+      else if (typeof args.file_path === "string") target = ` for ${JSON.stringify(args.file_path)}`;
+      else if (typeof args.file === "string") target = ` for ${JSON.stringify(args.file)}`;
+    }
+    const msg = `Error: 'view_image' is not available in Code Mode${target}. Inspect files or visual assets programmatically using tools.exec_command or code.`;
+    return `text(${JSON.stringify(msg)});\n`;
+  }
   return `const result = await tools.exec_command(${JSON.stringify(args)});\ntext(result);`;
 }
 

src/types/tools.ts

@@ -57,6 +57,7 @@ const CODE_MODE_HELPER_TOOL_NAMES = [
   ...LEGACY_SHELL_BRIDGE_TOOL_NAMES,
   "write_stdin",
   "apply_patch",
+  "view_image",
 ] as const;
 
 /**

tests/responses/legacy-shell-compat.test.ts

@@ -112,4 +112,16 @@ describe("code-mode helper compatibility", () => {
       expect(received).toEqual(input === "[]" ? [] : input);
     }
   });
+
+  test("view_image emits a friendly code-mode error message via text()", async () => {
+    const source = compileCodeModeHelperInput(
+      JSON.stringify({ path: "/root/banner.png" }),
+      "view_image",
+    );
+    let output: unknown;
+    const run = new AsyncFunction("tools", "text", source);
+    await run({}, (value: unknown) => { output = value; });
+    expect(output).toContain("Error: 'view_image' is not available in Code Mode for \"/root/banner.png\"");
+    expect(output).toContain("tools.exec_command");
+  });
 });

tests/responses/responses-undeclared-tool-guard.test.ts

@@ -1640,6 +1640,16 @@ describe("undeclaredToolCallNameInResponse", () => {
     expect(undeclaredToolCallNameInResponse(response, new Set())).toBe("write_stdin");
   });
 
+  test("accepts view_image through a bare unified exec declaration", () => {
+    const response = {
+      output: [{ type: "function_call", name: "view_image" }],
+    };
+
+    expect(undeclaredToolCallNameInResponse(response, new Set(["exec"]))).toBeUndefined();
+    expect(undeclaredToolCallNameInResponse(response, new Set(["view_image"]))).toBeUndefined();
+    expect(undeclaredToolCallNameInResponse(response, new Set())).toBe("view_image");
+  });
+
   test("never legacy-normalizes a namespaced shell bridge call", () => {
     // A namespaced call (e.g. an MCP server advertising its own exec_command) must be
     // matched by its full wire name only — never normalized to bare `exec`.