---
title: MARKLESS_ATTRIBUTE_OBJECT_VALUE
description: "Lowercase on* attributes are plain HTML attributes: a Markless compiler warning."
sidebar: { hidden: true }
search: { keywords: ["ATTRIBUTE_OBJECT_VALUE","attribute object value","markless error"] }
pagination: false
---

**Warning** from the compiler, while it builds your `.tsrx` files.

## What happened

Markless prints the message, the reason, and a suggestion:

```text
MARKLESS_ATTRIBUTE_OBJECT_VALUE: `<attributeName>={<valueSource>}` is a plain attribute, not a Markless event. It would serialize the function source into HTML.<eventText>
Attribute bindings serialize to plain text in HTML and DOM updates; only graph cells keep structured values across resume.
Use the event prop casing, for example `<eventSuggestion>={...}`, or serialize a string deliberately.
```

Words in angle brackets change from case to case.

## How to fix it

Start with the suggestion in the message above.

If you accept the warning on purpose, put this comment on the line above it:

```tsrx
// markless-allow MARKLESS_ATTRIBUTE_OBJECT_VALUE: the reason you accept it
```

This page has no guide yet. [Help write it](/contributing/improve-these-docs).

## Where it comes from

`@markless/compiler` raises this code. Source:

- [packages/compiler/src/passes/semantic-graph/diagnostics.ts](https://github.com/compiled-run/markless/blob/main/packages/compiler/src/passes/semantic-graph/diagnostics.ts)

Read [how to read a Markless error](/tooling/diagnostics), or go back to [all error codes](/errors).