# TSR1103: Ambient declaration '…' in a sound file asserts a value exists without checking it. Move it to a '.d.ts' file or import the real value.

> A 'declare' variable, function, class, enum or namespace in a sound file asserts a value exists unchecked. Move it to a .d.ts file or import it.

## What it means

`declare const`, `declare function`, `declare class`, `declare enum` and `declare namespace` in a sound `.ts` file tell the checker a value exists at runtime without proving it. It's reported at the declaration name.

## Example

```ts
// declare const in a sound file asserts a value exists.
declare const API_URL: string; // @expect TSR1103
export const url: string = API_URL;
```

## How to fix

- Import the real value instead.
- Or move the declaration into one project `.d.ts` file (for example `types/ambient.d.ts`).

Sound mode is defined in [design record 0007](https://github.com/Webb-Ventures/typescript-rust/blob/main/docs/design/0007-sound-mode.md) (accepted 2026-10-15).

Source: https://ts-r.dev/errors/TSR1103/