Support class-based client generation in @kubb/plugin-client

[Luc-cpl]

Hi there,

In my current use case it would be awesome if we could have a class-based client instead of the current function-based approach for client operations.

Kubb is very useful for building integrations with other platforms’ APIs in our SaaS — we just set a new config with the OpenAPI spec, and most of the heavy lifting is done automatically, with far fewer type issues.

However, as we handle queue-based mass integrations, relying on a centralized axios client doesn’t work. Right now, Kubb allows passing a custom client into generated functions, but that’s not very practical:

• We need to ensure it’s passed in every single call.
• If we miss it anywhere, the integration breaks.
• As a result, we have to implement internal tests just to make sure we don’t forget to pass the config.

Instead, I think it would be more reliable if @kubb/plugin-client supported generating classes with a centralized config per instance. That way we could share the client instance across calls, and we wouldn’t need to worry about injecting the custom fetcher on every operation.

Currently, we’re working around this by wrapping Kubb’s functions like so:

export function createClient(config: AuthConfig): ApiClient {
  const axiosClient = createAxiosClient(config);
  const fetcher = createFetcher(axiosClient);

  return {
    updateProductById: (productId, data, config) => {
      config = { client: fetcher, ...config };
      return operations.updateProductById(productId, data, config);
    },
    createProduct: (data, config) => {
      config = { client: fetcher, ...config };
      return operations.createProduct(data, config);
    },
    listAllProductVariations: (productId, params, config) => {
      config = { client: fetcher, ...config };
      return operations.listAllProductVariations(productId, params, config);
    },
    updateProductVariationById: (productId, variationId, data, config) => {
      config = { client: fetcher, ...config };
      return operations.updateProductVariationById(productId, variationId, data, config);
    },
  };
}

Proposal:

Add an option in @kubb/plugin-client to generate class-based clients instead of functions, with centralized configuration per instance.

This approach would reduce possible errors and make it easier to reuse configured clients across different function calls.

[stijnvanhulle]

@Luc-cpl Good idea, let use have a look at implementing this, I will move this to an issue to follow up.