A multi-channel laser-based chemical sensor platform is presented, in which a modular architecture allows the exchange of complete sensor channels without disruption to overall operation. Each sensor channel contains custom optical and electronics packages, which can be selected to access laser wavelengths, interaction path lengths and modulation techniques optimal for a given application or mission. Although intended primarily to accommodate mid-infrared external cavity quantum cascade lasers and astigmatic Herriott cells, channels using visible or near infrared lasers or other gas cell architectures can also be used, making this a truly versatile platform. Analog and digital resources have been carefully chosen to facilitate small footprint, rapid spectral scanning, low-noise signal recovery, fail-safe autonomous operation, and in-situ chemometric data analysis, storage and transmission. Results from the demonstration of a two-channel version of this platform are also presented.