# BUILDER_SLUG_COLLISION

An entity in `ui-schema.json` has the slug of a collection in `nextly.config.ts`.

## Cause

An entity in `ui-schema.json` has the slug of a collection in `nextly.config.ts`.

`nextly migrate:check` reads the entities the Schema Builder saved in `ui-schema.json` beside those in `nextly.config.ts`, and a slug may be declared in only one of them. The Why line lists each slug both files declare.

## Fix

* Remove each slug listed from one of the two files, or rename it in one of them.
* Run `nextly migrate:check` again.

## Example

```text
✗ An entity is defined in both `nextly.config.ts` and `ui-schema.json`.
  Why:  slug 'posts' is defined in both nextly.config.ts and ui-schema.json
  Next: Remove each slug listed from one of the two files, or rename it in one of them, then run the command again.
  Docs: https://nextlyhq.com/docs/cli/errors/builder-slug-collision  (BUILDER_SLUG_COLLISION)
```