> ## Documentation Index
> Fetch the complete documentation index at: https://trigger.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Emit Decorator Metadata

> Use the emitDecoratorMetadata build extension to enable support for the emitDecoratorMetadata TypeScript compiler option

If you need support for the `emitDecoratorMetadata` typescript compiler option, import the `emitDecoratorMetadata` build extension and use it in your `trigger.config.ts` file:

```ts theme={"theme":"css-variables"}
import { defineConfig } from "@trigger.dev/sdk";
import { emitDecoratorMetadata } from "@trigger.dev/build/extensions/typescript";

export default defineConfig({
  project: "<project ref>",
  // Your other config settings...
  build: {
    extensions: [emitDecoratorMetadata()],
  },
});
```

This is usually required if you are using certain ORMs, like TypeORM, that require this option to be enabled. It's not enabled by default because there is a performance cost to enabling it.

<Note>
  emitDecoratorMetadata works by hooking into the esbuild bundle process and using the TypeScript
  compiler API to compile files where we detect the use of decorators. This means you must have
  `emitDecoratorMetadata` enabled in your `tsconfig.json` file, as well as `typescript` installed in
  your `devDependencies`.
</Note>