PCC is designed to travel across domains — sensing, software, media, research, coordination, education, simulation and future execution — without rewriting its constitutional or semantic core for each surface.
Domain profiles supply vocabulary and evidence rules. Platform adapters supply transport or storage. The core preserves identity, evidence, authority, lineage, materiality, reconstruction and recovery.
Eight levels of interoperability
| Level | What participants preserve |
|---|---|
| Transport | Exchange bytes. |
| Syntactic | Understand envelopes and serialisation. |
| Semantic | Identity, field meaning, units and relations. |
| Epistemic | Evidence kind, provenance, confidence and derivation. |
| Temporal | Epochs, sequence, freshness, receipt and observation time. |
| Authority | What may observe, advise, propose, approve, execute — or never do. |
| Generative | What can be reconstructed, expanded, or must remain opaque. |
| Recovery | Detect divergence, resynchronise and rejoin after loss. |
PCC targets all eight levels. Today, semantic and epistemic interoperability are evidenced within declared bounds, with the higher levels in active development.
Why the higher levels matter
Most systems stop at transport and syntax. PCC treats authority and recovery as first-class: a participant should know not only what a message means but what may be done with it, and how to rejoin coherently after loss. This is what makes cooperation between heterogeneous systems trustworthy.
The native fabric
Native CXP and Thin-CXP implement these levels as a native semantic exchange fabric, including a profile for constrained devices. See Capabilities.