エラー

package main

import (
	"context"
	"errors"
	"fmt"
	"os"

	"github.com/squarecloudofc/sdk-api-go/v3"
)

func main() {
	ctx := context.Background()
	c := squarecloud.New(os.Getenv("SQUARECLOUD_API_KEY"))
	appID := "abc123def456abc123def456"

	err := c.Apps.Start(ctx, appID)

	var apiErr *squarecloud.APIError
	if errors.As(err, &apiErr) {
		fmt.Println(apiErr.Status, apiErr.Code, apiErr.Message)
		fmt.Println(apiErr.Method, apiErr.Path) // "POST" "/v2/apps/<id>/start"
	}
}

_, err := c.Apps.Get(ctx, appID)

switch {
case errors.Is(err, context.Canceled):
	// you canceled ctx
case errors.Is(err, context.DeadlineExceeded):
	// the deadline of ctx, or the default one, passed
}

func handle(err error) error {
	var apiErr *squarecloud.APIError
	if !errors.As(err, &apiErr) {
		return err
	}

	switch apiErr.Code {
	case squarecloud.CodeAppNotFound:
		return nil
	case squarecloud.CodeContainerAlreadyStarted:
		return nil // fine
	}
	switch {
	case apiErr.Status == 429:
		return retryLater()
	case apiErr.Status >= 500:
		return reportOutage(apiErr)
	}
	return err
}