`operationTypes` to simplify generated operation types

[alario-tang]

Feature Request: Option to simplify generated operation types

Problem

When generating TypeScript types for API operations, Kubb creates multiple type aliases that are often redundant:

// Generated in models/orderManagement/OrderManagementGetAllPortfolioTrades.ts

// Alias 1: Status code specific
export type OrderManagementGetAllPortfolioTrades200 = PortfolioTradesResponseCO;

// Alias 2: Error type
export type OrderManagementGetAllPortfolioTrades422 = HTTPValidationError;

// Alias 3: Another alias of alias
export type OrderManagementGetAllPortfolioTradesMutationResponse = OrderManagementGetAllPortfolioTrades200;

// Alias 4: Composite type
export type OrderManagementGetAllPortfolioTradesMutation = {
  Response: OrderManagementGetAllPortfolioTrades200;
  Request: OrderManagementGetAllPortfolioTradesMutationRequest;
  Errors: OrderManagementGetAllPortfolioTrades422;
};

In practice, I only need to import the base business type (PortfolioTradesResponseCO) directly. The operation-level aliases add noise and increase bundle size.

Proposed Solution

Add a configuration option like simplifiedTypes or operationTypes: false to skip generating operation-level type aliases:

pluginTs({
output: { path: './models' },
operationTypes: false, // Skip OrderManagementGetAllPortfolioTrades200, etc.
}),

pluginClient({
output: { path: './api' },
operationTypes: false, // Use base types directly in generated functions
}),

Expected Behavior

With operationTypes: false, the generated client function would directly use the base types:

// Before
import type {
OrderManagementGetAllPortfolioTradesMutationRequest,
OrderManagementGetAllPortfolioTradesMutationResponse,
OrderManagementGetAllPortfolioTrades422,
} from "../../models/...";

export async function orderManagementGetAllPortfolioTrades(
data: OrderManagementGetAllPortfolioTradesMutationRequest,
...
): Promise

// After (simplified)
import type {
PortfolioTradesQueryCO,
PortfolioTradesResponseCO,
} from "../../models";

export async function orderManagementGetAllPortfolioTrades(
data: PortfolioTradesQueryCO,
...
): Promise

Use Case

• Projects that don't need fine-grained error type handling per status code
• Cleaner imports in business code
• Smaller generated output

Alternatives Considered

1. Import base types manually - Works but defeats the purpose of generated types
2. Post-processing script - Adds complexity to the build pipeline

Would love to hear if this aligns with Kubb's design philosophy or if there's an existing way to achieve this. Thanks!