> ## 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` hooks into the esbuild bundle process and uses the TypeScript compiler API
> to compile files containing decorators. Enable `emitDecoratorMetadata` in your `tsconfig.json` and
> install `typescript` in your `devDependencies`.

## Using with TypeScript 7

TypeScript 7 does not expose the JavaScript compiler API required by this extension. Install the TypeScript 6 compatibility package alongside TypeScript 7:

```bash npm theme={"theme":"css-variables"}
npm install --save-dev @typescript/typescript6@latest
```

```bash pnpm theme={"theme":"css-variables"}
pnpm add --save-dev @typescript/typescript6@latest
```

```bash bun theme={"theme":"css-variables"}
bun add --dev @typescript/typescript6@latest
```

Your project continues using TypeScript 7 for its normal type checking and compiler commands. The extension loads the compatibility package only when it needs to emit decorator metadata.

Restart the Trigger.dev dev server after installing the package.


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