In this paper we show that integrated optics offer a very simple and low cost way to combine up to eight beams of an interferometric optical array. These beam combiners will allow accurate visibilities and phase closure terms measurements, and provide consequently, high quality information for astronomical image reconstruction. We present optical designs for two different chips. Using previous laboratory experiments we extrapolate the performances, constraints and limits of different beam combination concepts. In particular spatial encoding and temporal encoding of `all-in-one' schemes are compared and their main properties are evaluated.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.