> For the complete documentation index, see [llms.txt](https://docs.aurelia.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.aurelia.io/developer-guides/error-messages/0088-to-0723/aur0157.md).

# AUR0157

Binding command {{0}} has already been registered.

### **Error message**

Binding command {{0}} has already been registered.

### **Parameters**

1. `name`: The name of the binding command that already exists.

### Error explanation

This warning occurs when you attempt to register a binding command with a name that has already been registered in the container. Binding command names must be unique. While this is currently a warning (`console.warn`), it indicates a potential issue where the intended binding command might be overridden.

### Common causes

* Registering the same binding command class multiple times.
* Defining multiple binding commands with the same name.
* A plugin or library registering a binding command with a name that conflicts with one in your application.

### How to fix

* Ensure each binding command has a unique name.
* Check for duplicate registrations in your code and in any plugins you are using.
* If a plugin is causing the conflict, consult its documentation or consider renaming your binding command.

### Debugging tips

* Identify the duplicate binding command name from the warning message.
* Search your codebase and dependencies for where binding commands with this name are defined and registered.
* Temporarily remove or comment out binding command registrations to isolate the source of the duplication.


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