neXus: A heterogeneous, horizontal, coordinate-addressed runtime network for agents and executable systems.
neXus is a horizontal fabric where heterogeneous software systems — servers, agents, edge devices, data centers, and even human-operated terminals — attach to a common peer-to-peer network through a single lightweight binary, nex. Every attached node speaks the same coordinate-addressed I/O interface, regardless of its internal architecture. There is no hierarchy: any node can observe, act, or coordinate, and the fabric itself provides the shared blackboard. Retrieval is arithmetic, not indexed; the network scales horizontally without a central orchestrator. This whitepaper specifies the FIH (Fact, Intent, Hint) record model, the coordinate identity, the runtime, and the verified behavior of the reference implementation, marking established results and open questions.Generative agents, cloud functions, edge sensors, and human operators each speak different protocols and store state in incompatible backends. Coordinating across them typically requires a central orchestrator, an indexing layer, or a translation gateway — each adding latency, cost, and a single point of failure. neXus replaces the gateway with a fabric. Any software that can attach to a storage backend or an agent becomes a peer, speaking the same FIH interface. nex is the universal attachment point: a binary that runs unchanged on Wasm, microcontrollers, cloud VMs, and bare metal. Once attached, the backend becomes a blackboard; the agent becomes a peer. There is no master, no slave, no orchestrator — only a horizontal network of observers and actors where the observer is also an actor, and the actor is also an observer. The effect is a flat ecosystem: a sensor node can write Facts, a data center can read them, an agent can propose an Intent, and a human-operated system can apply Hints — all through the same coordinate-addressed I/O. Because identity is spatial (coordinate, not hash) and records are immutable, the cost of finding a record is independent of the number of records, and the cost of coordinating across nodes scales with the number of attachments, not with the amount of data. The reference code is published under Apache License 2.0. Where a claim is a hypothesis rather than a measured result, it is labeled as such. Model neXus is a computing model before it is a system. The model states what computation is: a directed path over immutable records, in which the record is the state and the traversal is the computation. This section states the model itself and the minimal skeleton (@sec-skeleton) that tests it; the following chapters specify the record kinds (@sec-fih), the coordinate identity (@sec-identity), the storage (@sec-storage), and the runtime (@sec-architecture) that realize it. *State.* A knowledge state is a triple $K = (F, I, H)$, where $F$ is the set of immutable Facts, $I$ is the set of active Intents, and $H$ is the set of active Hints. Every record carries a coordinate identity and a time coordinate, so $K$ is a spatiotemporal state, and the state of the system is its record. *Operation.* An operation is an Intent $i$ that departs from a set of Facts $\text{src}(i)$ and is bounded by a set of Hints $\text{bnd}(i)$. Concluding the Intent produces exactly one new Fact $f'$: $$ (\text{src}(i),\, i,\, \text{bnd}(i)) \;\vdash\; f' , $$ or, in the algebraic form the reference implementation uses, $F \times I \times H \rightarrow F'$. No Fact is overwritten; the state advances to $K' = K \cup \{f'\}$ with the concluded Intent removed. *Computation path.* A computation is a sequence of such steps, $$ \pi = (f_0, i_1, f_1, i_2, \dots, f_n) , $$ where each $f_k$ is the Fact concluded by $i_k$ from the Facts that precede it, $$ f_k = \mathrm{conclude}\big(\mathrm{src}(i_k),\, i_k,\, \mathrm{bnd}(i_k)\big), \qquad k = 1, \dots, n , $$ and because every step is recorded and no step depends on hidden state, replaying $\pi$ from its recorded Facts reproduces $f_n$ deterministically: replay equals computation. This equality is the property the model guarantees, the skeleton tests, and the storage layer makes measurable. *Closure.* A new capability is a new Intent or a new Hint composed over the same immutable Facts. There is no separate execution model to invent: complex systems are built by composition, and the properties demonstrated by the minimal calculator are the properties every complex design must preserve. *Scale.* The definitions hold at every scale, from a single agent to an ecosystem; an Observation at dimension $N$ becomes a Hint at dimension $N-1$, which is the property the project calls homeomorphic and which is specified with the scaling modes in @sec-recursion.