FIG.02 · THE UNIT
If Mesh Cognition is the architecture, the cognition node is its unit. A node is a sovereign participant in the mesh's exchange of typed observations — it holds its own memory, decides locally, field by field, what to admit, and contributes observations with lineage. This distinguishes the pattern from centrally orchestrated multi-agent systems.
In the common multi-agent picture, an "agent" is a prompt-and-tools loop, and a central orchestrator decides which one runs and what it sees. A cognition node is instead defined by its local state and its admission boundary, not by an internal loop or a graph someone wired. MMP requires no central orchestrator and no central admission registry. Three properties constitute the node: its data model, receiver-autonomous per-field admission, and remix-with-lineage are protocol-level; the self-selection that follows from them is the architectural pattern above the protocol.
A node keeps its own store: the Cognitive Memory Blocks it authored, plus the ones it admitted from peers — each carrying fields from the CAT7 typed vocabulary, and, when derived from another block, retaining lineage to its source. A node may also learn locally from what it observes. That learned state, like its memory, is per-node and not merged: MMP carries observations, not weights, hidden state, or learned parameters, and it does not merge per-node learned state. A node's internal learned state remains local. Sovereignty is what the protocol carries and what it refuses to carry.
Every incoming block is evaluated by the receiver, field by field, under its own admission policy — the mechanism the specification calls SVAF (§9). The receiver determines the admission outcome for each field; admission is receiver-autonomous. When a node remixes admitted material, the resulting block retains lineage to its source observations, so provenance is preserved without merging state. A node may decline to contribute; silence is a valid outcome.
Because admission is the node's own decision, participation is self-selected. Each node decides locally whether to admit the input, act on it, and contribute an observation; the pattern does not require a central component to assign participation. Coordination is an emergent product of many receiver-local decisions rather than the output of a conductor — so the protocol introduces no required central admission controller.
Because a node is defined by its boundary and not its internals, the participant behind an admission boundary may be any participant form that honours the node contract: a single model, a rules process, a person, or an entire multi-agent system. What the mesh sees is one sovereign store, one admission boundary, and one self-selecting participant; how that participant decides internally — a planner, a deliberation process, or a sub-mesh of its own — is private to it. The definition is therefore recursive: a mesh of nodes can present as a single node to a larger mesh, and the same node contract can be applied recursively across mesh boundaries. The topology term for this case is the gateway — a node holding membership in two meshes at once, admitting into each on its own terms. The distinction between one composite node and several separate ones depends on where the boundary is drawn: agents behind a single admission boundary are one node; agents each carrying their own boundary onto the parent mesh are several. Composition does not change what grounds trust — a composite's contributions still stand on consequences reality confirms, however elaborate its internal deliberation.
A node admits typed symbols; connecting those symbols to reality — grounding — is the open problem of the research program. Lineage establishes provenance (where a claim came from), which is not the same as truth (whether it holds): MMP does not treat provenance as evidence of truth. A node's standing is meant to follow from consequences reality confirms, not from peers agreeing with it. How such consequences are measured and verified is outside MMP 1.x and remains an open research question.
The node definition establishes the protocol's boundaries for state, admission, and exchange. Center-free coordination is what follows when sovereign nodes self-select through admission. Remix lineage makes the provenance of derived blocks reconstructible. And because MMP requires no central controller, the protocol imposes no central point of failure. The node is where sovereignty, admission, and lineage meet — the reason a mesh of them can coordinate without a center.
The node is specified normatively in the Mesh Memory Protocol (CAT7 blocks, per-field admission, remix-with-lineage), implemented by the listed projects, and analysed in the research.