[BUG] createMany fails with 'Invariant failed' when policy plugin is active (V3)

[olup]

Bug Description

createMany operations fail with an Invariant failed error when the @zenstackhq/plugin-policy is enabled and models have access control policies involving nested relation traversals.

Switching to individual create calls in a loop resolves the issue. This occurs on multiple models, not just a single one.

Environment

• ZenStack version: @zenstackhq/orm ^3.3.3, @zenstackhq/plugin-policy ^3.3.3, @zenstackhq/cli ^3.3.3
• Prisma version: 7.3.0
• Database: PostgreSQL
• Node.js: v22
• Integration: Using zenstack-trpc (^0.1.22) to auto-generate CRUD routes

Schema (minimal reproduction)

The policy plugin is enabled:

plugin policy {
    provider = '@zenstackhq/plugin-policy'
}

Here is a simplified version of the models involved. The key aspect is that access policies traverse multiple nested relations:

model HomePage {
    id        String   @id @default(cuid())
    projectId String   @unique
    project   Project  @relation(fields: [projectId], references: [id], onDelete: Cascade)
    cards     HomeCard[]

    @@allow('all', auth().role == SUPER_ADMIN)
    @@allow('all', auth().role == PARTNER_ADMIN && project.organization.partnerManagers?[userId == auth().id])
    @@allow('all', auth().role == ORG_ADMIN && auth().organizationId == project.organizationId)
    @@allow('all', auth().role == USER && auth().organizationId == project.organizationId)
}

model HomeCard {
    id         String            @id @default(cuid())
    title      TranslatedField[] @json
    subtitle   TranslatedField[] @json
    icon       String?
    mainColor  String?
    order      Int               @default(0)
    type       HomeCardType      @default(AGENT)

    homePageId String
    homePage   HomePage @relation(fields: [homePageId], references: [id], onDelete: Cascade)

    // Policies traverse deeply nested relations: homeCard -> homePage -> project -> organization -> partnerManagers
    @@allow('all', auth().role == SUPER_ADMIN)
    @@allow('all', auth().role == PARTNER_ADMIN && homePage.project.organization.partnerManagers?[userId == auth().id])
    @@allow('all', auth().role == ORG_ADMIN && auth().organizationId == homePage.project.organizationId)
    @@allow('all', auth().role == USER && auth().organizationId == homePage.project.organizationId)
}

The Project model links to Organization, which has a partnerManagers relation (a join table with userId and organizationId). So the PARTNER_ADMIN policy on HomeCard traverses 4 levels of relations: homePage.project.organization.partnerManagers?[...].

Steps to Reproduce

1. Enable the policy plugin
2. Define models with @@allow policies that traverse multiple nested relations (3-4 levels deep)
3. Call createMany on one of these models (e.g., via the auto-generated tRPC/REST endpoint)

Error

POST /generated/homeCard/createMany → 400 Bad Request

{
  "error": {
    "message": "Failed to execute query: Error: Invariant failed",
    "code": "INTERNAL_SERVER_ERROR"
  }
}

The request body contains a standard createMany payload with an array of data objects (scalar fields only, no nested relations).

Workaround

Replacing createMany with individual create calls in a loop works without any issues:

// This fails:
await db.homeCard.createMany({ data: items });

// This works:
for (const item of items) {
  await db.homeCard.create({ data: item });
}

Additional Context

• The issue is not specific to the HomeCard model — it happens on other models with similar deeply nested relation policies as well.
• The error message Invariant failed is non-descriptive and makes debugging difficult. A more specific error message would be very helpful.
• Based on issue #1712, ZenStack V2 internally translated createMany to individual create calls when access policies are involved. It's possible this translation has a bug in V3 when policies involve deep relation traversals.
• The authenticated user context is properly set (individual create calls work fine with the same auth context).

[olup]

Note: This issue was written by Claude (AI) under human supervision.

[sanny-io]

As I understand it, the invariant function only hides its error message in production.

@olup what error does it say in dev?