How to auto generate Feign client in java\kotlin based on api interface?

I have that api interface for my next controller in spring boot

@RequestMapping("/v1/resource")
@Validated
interface ResourceApi {

    @Operation(summary = "get resource")
    @PostMapping("/get")
    fun getResource(
        @RequestBody request: GetRequest,
    ): PageableResult<GetResponse>

    @Operation(summary = "upsert resource")
    @PostMapping("/upsert")
    fun upsertResource(
        @RequestBody request: UpsertRequest,
    ): PageableResult<UpsertResponse>
}

I need auto generate somehow Feign client for that api like that

@FeignClient(
    contextId = "resourceClient",
    name = "service",
    path = "/v1/resource"
)
interface ResourceClient {

    @PostMapping("/get")
    fun getResource(
        @RequestBody request: GetRequest
    ): PageableResult<UpsertResponse>

    @PostMapping("/upsert")
    fun upsertResource(
        @RequestBody request: UpsertRequest
    ): PageableResult<UpsertResponse>
}

I am not interested on openapi generation like that guide or etc

Can OpenApi Generator generate interface feign clients?

You can solve that maintain based on basic inheritance. Also you must not describe @RequestMapping in api class due to error creating bean then feign client will be initialized

My code works nice with that:

@Validated
interface ResourceApi {

    @Operation(summary = "get resource")
    @PostMapping("/v1/resource/get")
    fun getResource(
        @RequestBody request: GetRequest,
    ): PageableResult<GetResponse>

    @Operation(summary = "upsert resource")
    @PostMapping("/v1/resource/upsert")
    fun upsertResource(
        @RequestBody request: UpsertRequest,
    ): PageableResult<UpsertResponse>
}

And Feign client

@FeignClient(
    contextId = "resourceClient",
    name = "service"
)
interface ResourceClient : ResourceApi