Emitted contract.d.ts does not match contract shape in RC 13/10

[RyanGarber]

Package and version

prisma@8.0.0-rc.13, @prisma/orm-postgres@8.0.0-rc.10

What happened?

The contract.d.ts emitted by the Prisma CLI (RC 13) is missing nullable fields in every to-one relation, causing type errors because the new contract shape requires the field to be present.

What did you expect to happen?

The CLI emits the correct shape (nullable fields present in every relation in the contract.d.ts) or the fields made truly optional at call sites.

Minimal reproduction

• Create a new project with any to-one relations (e.g. model ModelA { related ModelB ... })
• Inspect the emitted contract.d.ts for readonly nullable in the relation's schema or pass the emitted schema to DefaultModelRow as a type argument and typecheck

Environment

• Node 24.14.0
• pnpm 12.3.4
• macOS 27 Developer Preview
• Postgres 18.4

Additional context

Result from passing the emitted contract to DefaultModelRow<Contract...>:

error TS2344: Type 'Contract' does not satisfy the constraint 'Contract<SqlStorage<string>>'.  
   The types of 'domain.namespaces' are incompatible between these types.  
     Type '{ readonly public: { readonly models: { readonly Account: { readonly fields: { readonly id: { readonly nullable: false; readonly type: { readonly kind: "scalar"; readonly codecId: "pg/text@1"; }; }; readonly accountId: { readonly nullable: false; readonly type: { ...; }; }; ... 10 more ...; readonly updatedAt: { ......' is not assignable to type 'Readonly<Record<string, ApplicationDomainNamespace>>'.  
       Property 'public' is incompatible with index signature.  
         Type '{ readonly models: { readonly Account: { readonly fields: { readonly id: { readonly nullable: false; readonly type: { readonly kind: "scalar"; readonly codecId: "pg/text@1"; }; }; readonly accountId: { readonly nullable: false; readonly type: { ...; }; }; ... 10 more ...; readonly updatedAt: { ...; }; }; readonly re...' is not assignable to type 'ApplicationDomainNamespace'.  
           Types of property 'models' are incompatible.  
             Type '{ readonly Account: { readonly fields: { readonly id: { readonly nullable: false; readonly type: { readonly kind: "scalar"; readonly codecId: "pg/text@1"; }; }; readonly accountId: { readonly nullable: false; readonly type: { readonly kind: "scalar"; readonly codecId: "pg/text@1"; }; }; ... 10 more ...; readonly upd...' is not assignable to type 'Record<string, ContractModelBase<Readonly<Record<string, unknown>>>>'.  
               Property 'Account' is incompatible with index signature.  
                 Type '{ readonly fields: { readonly id: { readonly nullable: false; readonly type: { readonly kind: "scalar"; readonly codecId: "pg/text@1"; }; }; readonly accountId: { readonly nullable: false; readonly type: { readonly kind: "scalar"; readonly codecId: "pg/text@1"; }; }; ... 10 more ...; readonly updatedAt: { ...; }; };...' is not assignable to type 'ContractModelBase<Readonly<Record<string, unknown>>>'.  
                   Types of property 'relations' are incompatible.  
                     Type '{ readonly user: { readonly to: { readonly namespace: "public" & { readonly __brand: "NamespaceId"; }; readonly model: "User"; }; readonly cardinality: "N:1"; readonly on: { readonly localFields: readonly ["userId"]; readonly targetFields: readonly [...]; }; }; }' is not assignable to type 'Record<string, ContractRelation>'.  
                      Property 'user' is incompatible with index signature.  
                         Type '{ readonly to: { readonly namespace: "public" & { readonly __brand: "NamespaceId"; }; readonly model: "User"; }; readonly cardinality: "N:1"; readonly on: { readonly localFields: readonly ["userId"]; readonly targetFields: readonly [...]; }; }' is not assignable to type 'ContractRelation'.  
                           Property 'nullable' is missing in type '{ readonly to: { readonly namespace: "public" & { readonly __brand: "Names

[anthonyclarka2]

seeing this exact issue too.

[ArjunCodess]

hi, i'd like to work on this.

emitted contract.d.ts drops nullable on every to-one relation, so defaultmodelrow rejects the contract. i'd add readonly nullable to each relation in the emit, matching contractrelation, for both optional and required n:1 sides.

should required relations still get nullable: false, or only optional ones? and is this only the dts emitter, or does the runtime json miss it too?