Options

pluginBarrel takes no arguments. You configure it through output.barrel, either on defineConfig to set the root barrel and the default every plugin inherits, or on a single plugin to override that plugin's barrel.

Option	Type	Default	Description
output.barrel	{ type: 'all' | 'named' } | false	false	Re-export style for the barrel files
type	'all' | 'named'	Required	Named exports or a wildcard export
nested	boolean	false	Write an index.ts in every subdirectory

output.barrel

Toggle the export style and depth to see the generated barrels.

• src/gen/
• models/
• Pet.ts
• User.ts
• clients/
• pet/
• getPetById.ts
• store/
• getInventory.ts

src/gen/index.ts

Controls how the generated index.ts (barrel) re-exports the output. Accepts { type: 'named' } or { type: 'all' }, optionally with nested: true (for example { type: 'named', nested: true }) to write an index.ts in every subdirectory, or false to skip the barrel entirely. Kubb reads the plugin's own output.barrel first, falls back to config.output.barrel on defineConfig, and finally to false. Every generator plugin ships a default output that sets barrel: { type: 'named' }, but passing your own output replaces that object wholesale, so repeat barrel whenever you set output yourself.

The type field picks the export style. A plugin's output.barrel also accepts nested, so the plugin writes an index.ts in every subdirectory. The root output.barrel has no nested field and always stays flat.

Call a plugin with no output at all and it uses its own default, which already sets barrel: { type: 'named' }. The moment you pass an output object of your own, that default is replaced whole, so a plugin configured as pluginTs({ output: { path: 'types' } }) has no barrel of its own and falls back to config.output.barrel, which is false unless you set it.

Set barrel: { type: 'named' | 'all' } on defineConfig to enable barrels everywhere: a root barrel, and the default every plugin without its own output.barrel inherits. A plugin that sets its own output.barrel overrides that inherited value, including back to false, which also drops its files from the root barrel.

Type:	{ type: 'all' | 'named', nested?: boolean } | false
Default:	false

type

Export style for the barrel files. Required whenever output.barrel is set to an object.

• 'named' re-exports each symbol by name from the file's named exports. Best for tree-shaking and explicit imports.
• 'all' uses export *, a smaller barrel that re-exports everything.

Type:	'all' | 'named'
Default:	Required, no default

'named'

// src/gen/index.ts
export { getUser, User } from './api/user'
export { getPost, Post } from './api/post'
export { User } from './api/types/User'

'all'

// src/gen/index.ts
export * from './api/user'
export * from './api/post'
export * from './api/types/User'

nested

Changes what each barrel references. A barrel is written for every directory either way. With nested: false, the plugin's top barrel reaches through to the leaf files. With nested: true, each barrel re-exports only what sits directly inside its directory, including the subdirectory barrels below it, so callers can import from any depth. This field works on a plugin's output.barrel only.

Type:	boolean
Default:	false

nested: false (default) → barrels reference leaf files

// src/gen/api/index.ts
export * from './user'
export * from './post'
export * from './types/User'

// src/gen/api/types/index.ts
export * from './User'

nested: true → barrels reference sub-barrels

// src/gen/api/index.ts re-exports its files and subdirectories
export * from './user'
export * from './post'
export * from './types'

// src/gen/api/types/index.ts re-exports its files
export * from './User'