Present-day blockchain architectures all suffer from a number of issues not least practical means of extensibility and scalability. We believe this stems from tying two very important parts of the consensus architecture, namely canonicality and validity, too closely together. This paper introduces an architecture, the heterogeneous multi-chain, which fundamentally sets the two apart. In compartmentalising these two parts, and by keeping the overall functionality provided to an absolute minimum of security and transport, we introduce practical means of core extensibility in situ. Scalability is addressed through a divide-and-conquer approach to these two functions, scaling out of its bonded core through the incentivisation of untrusted public nodes. The heterogeneous nature of this architecture enables many highly divergent types of consensus systems interop- erating in a trustless, fully decentralised “federation”, allowing open and closed networks to have trust-free access to each other. We put forward a means of providing backwards compatibility with one or more pre-existing networks such as Ethereum. We believe that such a system provides a useful base-level component in the overall search for a practically implementable system capable of achieving global-commerce levels of scalability and privacy.