# TSR0010: … (sound mode enables 'isolatedDeclarations').

> Sound mode turned on 'isolatedDeclarations' and tsc's error for it fired. Add the explicit type the wrapped message asks for.

## What it means

Sound files require explicit types on exports (`isolatedDeclarations`), so every rule can be decided one file at a time. When your tsconfig doesn't set the flag and only sound mode turns it on, tsc's diagnostic for it is reported with this TSR code and tsc's own message in `{0}`, so a comparison with tsc shows why ts-r reports more. If the tsconfig already sets the flag, tsc's own code is reported instead.

## How to fix

- Do what the wrapped tsc message asks: usually add an explicit type annotation to the exported declaration.
- Or set `isolatedDeclarations` in tsconfig.json yourself, so the error keeps tsc's code and tsc reports it too.

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/TSR0010/