# X_REFERENCE_APP_UNREFERENCED

## Means

a tracked app typechecks but the root `tsconfig.json` does not reference it

## Typical cause

the app came off the `typecheck` pin without joining the root `tsc -b` solution, so the packages' emitted `.d.ts` are never proved consumable

## Fix

add `{ "path": "./<the app>" }` to the `references` array in `tsconfig.json` — `fix` carries the exact entry

[CLI and verify](/error-codes#cli-and-verify)