Federated Computing as Code (FCaC) Sovereignty-aware Systems by Design

Federated computing (FC) enables collaborative computation-such as machine learning, analytics, or data processing-across distributed organizations while keeping raw data local. Built on four architectural pillars: (a) distributed data assets (local control), (b) federated services (in-place computation), (c) standardized APIs (interoperability), and (d) decentralized services (multi-party control), FC provides the foundation for sovereignty-preserving collaboration. However, federated systems spanning organizational and jurisdictional boundaries lack a unified mechanism for enforcing sovereignty-critical governance constraints. They commonly depend on runtime policy evaluation, shared trust infrastructure, or institutional agreements that scale poorly and provide limited cryptographic guarantees. Federated Computing as Code (FCaC) proposes a declarative architecture that enforces governance by compiling authority and delegation into cryptographically verifiable artifacts rather than relying on online policy interpretation (cf. runtime policy evaluation). Boundary admission is a local verification step rather than a policy decision service. FCaC separates constitutional admission (permission to execute and delegate across sovereignty boundaries) from operational control (context-dependent procedures during execution). Admission is validated locally and statelessly at execution boundaries using proof-carrying capabilities, while stateful services may implement post-admission controls such as Attribute-Based Access Control (ABAC), risk scoring, quotas, and workflow state. FCaC introduces Virtual Federated Platforms (VFPs) that compose Core, Business, and Governance contracts through a cryptographic trust chain-Key Your Organization (KYO), Envelope Capability Token (ECT), and Proof-of-Possession (PoP) bindings. We validate the approach end-to-end on a cross-silo federated learning workflow using MNIST as a surrogate workload, releasing a reproducible open-source proof-of-concept that demonstrates envelope issuance, cryptographic admission (ECT+DPoP), and envelope-triggered training under mTLS. <br> <br> Code and artifacts: https://github.com/onzelf/FCaC-MNIST.