---
title: MARKLESS_ATTACH_HOST_ELEMENT_REQUIRED
description: "attach can only be bound to host elements: a Markless compiler error."
sidebar: { hidden: true }
search: { keywords: ["ATTACH_HOST_ELEMENT_REQUIRED","attach host element required","markless error"] }
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---

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

## What happened

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

```text
MARKLESS_ATTACH_HOST_ELEMENT_REQUIRED: Cannot bind attach={<source>} on component <owner>. attach installs DOM behavior and needs a concrete host element owner.
Element behaviors are resumed by locating the owning DOM element. A component is not a DOM locator and may render zero, one, or many host nodes.
Move attach={...} to a host element such as <canvas>, or make the component forward behavior to a known host element in its own TSRX body.
https://markless.dev/errors/MARKLESS_ATTACH_HOST_ELEMENT_REQUIRED
```

Words in angle brackets change from case to case.

## How to fix it

Start with the suggestion in the message above.

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).