Technology is described for providing code modules for building a device. An indication of hardware components to be used when designing a device may be received. A use case for the device may be received. A list of code modules that are compatible with the hardware components may be provided. The list of code modules may be based on the use case for the device. A selection of code modules may be received from a list of code modules that are compatible with the hardware components. The code modules may be provided for use in designing the device.