skipLibCheck exempts .d.ts contents from being checked, so assertions written inside wrnexus.generated.d.ts were never evaluated by tsc. Emit them into wrnexus.generated.api-checks.ts instead, referencing the WRNexusGenerated namespace's helper types (which stay in the .d.ts). Track the new generated file in check:generated-types. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>