Auto CRUD

Kruda can generate a full set of CRUD endpoints from a service interface using the Resource package-level function.

ResourceService Interface

Implement the ResourceService[T, ID] interface:

type ResourceService[T any, ID comparable] interface {
    List(ctx context.Context, page int, limit int) ([]T, int, error)
    Create(ctx context.Context, item T) (T, error)
    Get(ctx context.Context, id ID) (T, error)
    Update(ctx context.Context, id ID, item T) (T, error)
    Delete(ctx context.Context, id ID) error
}

Note: List returns items, total count, and error. It receives page and limit for pagination.

Registration

Register a resource to auto-generate routes:

type User struct {
    ID    string `json:"id"`
    Name  string `json:"name"`
    Email string `json:"email"`
}

type UserService struct {
    // your storage implementation
}

func (s *UserService) List(ctx context.Context, page, limit int) ([]User, int, error) { /* ... */ }
func (s *UserService) Get(ctx context.Context, id string) (User, error)               { /* ... */ }
func (s *UserService) Create(ctx context.Context, item User) (User, error)            { /* ... */ }
func (s *UserService) Update(ctx context.Context, id string, item User) (User, error) { /* ... */ }
func (s *UserService) Delete(ctx context.Context, id string) error                    { /* ... */ }

// Register — generates 5 routes automatically
kruda.Resource[User, string](app, "/users", &UserService{})

This generates:

Method	Path	Handler
GET	/users	List(ctx, page, limit)
GET	/users/:id	Get(ctx, id)
POST	/users	Create(ctx, item)
PUT	/users/:id	Update(ctx, id, item)
DELETE	/users/:id	Delete(ctx, id)

Group Resource

Register resources on a route group:

func GroupResource[T any, ID comparable](g *Group, path string, svc ResourceService[T, ID], opts ...ResourceOption) *Group

api := app.Group("/api/v1")
kruda.GroupResource[User, string](api, "/users", &UserService{})

Custom Options

Customize the generated routes with ResourceOption:

kruda.Resource[User, string](app, "/users", &UserService{},
    kruda.WithResourceMiddleware(authMiddleware),
    kruda.WithResourceOnly("LIST", "GET"),
    kruda.WithResourceIDParam("userId"),
)

WithResourceMiddleware

func WithResourceMiddleware(mw ...HandlerFunc) ResourceOption

WithResourceOnly

func WithResourceOnly(methods ...string) ResourceOption

Only generate specified actions (uppercased: "LIST", "GET", "CREATE", "UPDATE", "DELETE").

WithResourceExcept

func WithResourceExcept(methods ...string) ResourceOption

Generate all actions except the specified ones.

WithResourceIDParam

func WithResourceIDParam(param string) ResourceOption

Customize the ID parameter name (default: "id").

Error Mapping Integration

Combine with error mapping for clean error responses:

var ErrUserNotFound = errors.New("user not found")

app.MapError(ErrUserNotFound, 404, "User not found")

// Now Get() returning ErrUserNotFound automatically responds with 404

See Resource API for the full reference.