1. Conventions and Terminology

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in RFC 2119.

Naming note

Layer 6 was called xMesh in the v0.2.x drafts and in the published papers (arXiv:2604.19540, arXiv:2604.03955). As of v1.0.1 the layer is named Cognitive State. The name xMesh now refers to the product runtime — the reference implementation of the receiver side; the open substrate SDK is SYM, and the protocol itself is this open specification. The wire frame type xmesh-insight retains its identifier for backward compatibility and is unchanged.

Term Definition
Node A sovereign participant in the mesh: a unique cryptographic identity, its own admission function (SVAF), and its own memory store. Every agent that participates in coupling is a full peer node; Layer 6 cognitive state (an LNN) is optional (Section 13). Reading tiers: wire-contract sections of this document are MMP Core, frozen and byte-testable (Class 1, Section 17.1); receiver-side sections document the SYM reference runtime (Class 2, Section 17.2) — fully published, open-source reference, not a conformance target. A relay is pure routing infrastructure (Section 4.4) — it forwards frames and holds no identity, store, or cognitive state; it is not a node.
Peer Another node that this node has an active transport connection with and has completed a handshake.
Frame A single protocol message: one JSON object delivered as one transport message — length-prefixed over raw byte streams, message-delimited over WebSocket (Section 4.1).
Membrane The boundary behavior that makes something a node: a stable identity, a CAT7 projection of its state, and sovereign SVAF admission of others’ projections. The interior behind the membrane is unconstrained (Section 5.10).
Atom A node whose interior is a single agent (mind + store + SVAF) — the ordinary case. Atom and gateway nodes share the same membrane (Section 5.10).
Gateway A node whose interior is a sub-mesh. It participates in its interior group as an ordinary node and presents a boundary to exterior gateways; what crosses is its own lossy CAT7 projection of admitted interior cognition, never a relayed interior frame (Sections 5.9–5.11).
CMB Cognitive Memory Block — a structured memory unit with 7 typed semantic fields (CAT7 schema). Emitted, it is a projection; admitted by a peer, it is that peer’s observation. See Section 8.
Projection An emitted CMB seen from its author: a lossy, typed (CAT7) view of the agent’s private cognitive state — never the state itself. Each agent emits projections of its state on its own clock.
Observation An admitted projection seen from its receiver: a peer’s projection that cleared SVAF (Section 9.2) and is integrated as a measurement of an evolving latent. The same CMB is a projection to its author and an observation to a receiver that admits it.
Drift A scalar in [0, 1] measuring cognitive distance between an incoming signal and the receiver’s local state — computed per field (δ_f) and aggregated to a total drift. It is a signal-to-local-state measure, not a node-to-node one. See Section 9.1.
Coupling The receiver-autonomous process by which a node evaluates incoming signals (SVAF per-field evaluation, Section 9) and lets admitted signals influence its own evolving cognitive state through its own model. A node never imports or averages a peer’s hidden state (Section 2.7); coupling influences, it never overrides.
SVAF Symbolic-Vector Attention Fusion — per-field content-level evaluation of incoming memory signals. See Section 9.
Synthetic Memory Layer 5 — derived knowledge generated by the agent’s LLM reasoning on the remix subgraph, encoded into CfC-compatible hidden state vectors.
Remix When an agent processes a CMB through its domain intelligence and produces a NEW CMB with lineage pointing to the original. The original is remixed, not copied.
Lineage Each CMB carries parents (direct) and ancestors (full ancestor chain). Ancestors enable any agent in the remix chain to trace its contribution.
Canon The retention tier for committed cognition: a CMB at validated or canonical lifecycle is exempt from age-based purge while it holds that lifecycle (Section 6.3).
Grounding Evidence, where validation is judgment: a grounding CMB records that its author observed a real-world outcome (verified: or failed:) for the cognition its lineage points at (Section 6.7, draft).
Earned Authority Lifecycle roles (participant → validator → anchor) conferred by signed, revocable role-grants rooted at a pinned anchor. A node’s role is resolved through the grant chain, never taken from its advertised handshake role (Sections 6.5–6.6).
Mesh Cognition The agent’s LLM reasoning on the remix subgraph of CMBs — traced via lineage ancestors — to generate understanding that the agent’s previous state of mind didn’t have. Spans Layers 4–7. See Section 2.5.
Cognitive State Layer 6 — each agent’s own Liquid Neural Network (LNN). Evolves continuous-time cognitive state from Synthetic Memory input. Fast τ neurons track mood; slow τ neurons preserve domain expertise. (Called xMesh in v0.2.x drafts and the published papers — see the §1 naming note.)
CfC Closed-form Continuous-time neural network (Hasani et al., 2022). The LNN architecture used in the Cognitive State layer. Hidden state evolves through learned time-dependent interpolation gates.