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Published: 2025-09-22

Introducing Kubb v4

Kubb v4 sharpens type safety, schema generation, and query handling. Here is what changed.

Breaking changes

• Correct use of Infinite Query generics with Tanstack-Query
• Unwrap in Vue infinite query
• Different use of z.optional Before:

z.number().int().optional()

After:

z.optional(z.number().int())

• Add Key suffix to types when using asConst Before:

export const findPetsByStatusQueryParamsStatusEnum = {
  available: 'available',
  pending: 'pending',
  sold: 'sold',
} as const

export type FindPetsByStatusQueryParamsStatusEnum = (typeof findPetsByStatusQueryParamsStatusEnum)[keyof typeof findPetsByStatusQueryParamsStatusEnum]

After:

export const findPetsByStatusQueryParamsStatusEnum = {
  available: 'available',
  pending: 'pending',
  sold: 'sold',
} as const

export type FindPetsByStatusQueryParamsStatusEnumKey = (typeof findPetsByStatusQueryParamsStatusEnum)[keyof typeof findPetsByStatusQueryParamsStatusEnum]

👋🏽 Stijn Van Hulle