In an approach to providing completion support and on demand validation in a web tool that operates on live resources, one or more computer processors create one or more lists of content, where the one or more lists of content include one or more references to one or more runtime objects. The one or more computer processors parse the one or more lists of content. The one or more computer processors populate one or more lists of one or more choices with the parsed one or more lists of content. The one or more computer processors create one or more callbacks for one or more runtime objects referenced by the one or more lists of one or more choices.