Constitutional Codec Architecture — CCA v0.1.0
A framework for understanding, designing, and governing the URS codec ecosystem — what qualifies as a codec family, what belongs in a semantic profile, and how they interoperate without fragmentation.The Hierarchy
Reality
→ Constitution (USCP → USC)
→ UCRT (Universal Constitutional Representation Theory — what can be represented)
→ URS (Universal Representation System — how it is represented)
→ CCA (Constitutional Codec Architecture — how it is encoded)
→ CSP (Constitutional Semantic Profiles — what specialised semantics)
→ Ontologies (domain-specific meaning)
→ Applications (concrete use)Each layer has a distinct responsibility and evolves independently. Each constrains the layer below. Each derives from the layer above.
| Layer | Responsibility | Evolves | Scope |
|---|---|---|---|
| UCRT | What can be represented | Rarely | Epistemic — boundaries of representable reality |
| URS | How entities are structurally represented | Frozen | Data model — 5 kinds, 23 invariants |
| CCA | How representations are encoded | Occasionally | Codec taxonomy, interop rules, profiles |
| CSP | What specialised semantics a codec carries | Periodically | Trust, governance, execution, reasoning, ... |
| Ontologies | What domain-specific meaning exists | Frequently | Healthcare, law, finance, science, ... |
Core Architectural Principle
Strict about outcomes, tolerant about methods.
A new codec family is justified only when it requires fundamentally new representation semantics that cannot be expressed cleanly within an existing codec.
Implementation choices (language, transport, storage, cryptographic primitives) are never grounds for a new codec family. They belong in conformance profiles.
This principle prevents ecosystem fragmentation while preserving innovation.
What to Build When
Ask this question in order:
1. Can it be expressed as an ontology? → Build an ontology (domain vocabulary referencing existing codecs). 2. Can it be expressed as a semantic profile? → Build a CSP (constrained semantics on an existing codec). 3. Can it be expressed as a codec variant? → Build a codec family member (e.g., DAG-CBOR-LD alongside DAG-JSON-LD). 4. Does it require new representation semantics? → Build a new codec family.
Most things people reach for as "a new format" are ontologies (1) or profiles (2).
Codec Family Candidates
A codec family is a set of semantically-related codecs that share a common processing model and interoperate transparently. A codec family is fundamental if it introduces representation semantics the base URS model does not provide.
Strong Fundamental Candidates
These introduce distinct representation capabilities — each justifies dedicated specification:
| Family | Core Semantic | Processing Requirement | Distinct From |
|---|---|---|---|
| **DAG-Constitution-LD** | Constitutional rules, governance, authority, invariants | Rule evaluation, authority chain verification | Provenance in URS is structural; governance is procedural |
| **DAG-Trust-LD** | Trust assertions, attestations, reputation, verification chains | Chain-of-trust traversal, revocation checks | Not identity (URS Identifier) — trust is a derived semantic over identity |
| **DAG-Proof-LD** | Formal proofs, evidence, conformance, mathematical verification | Proof validation, invariant checking | Not trust (assertion) — proof is formal derivation |
| **DAG-Reason-LD** | Structured reasoning, inference, justification, provenance of conclusions | Inference engine, justification graph traversal | Not proof (mathematical) — reasoning is defeasible |
| **DAG-Agent-LD** | AI agent capabilities, goals, memory, interactions | Agent lifecycle, capability resolution | Not component (UWA) — agents adapt; components execute |
| **DAG-Exec-LD** | Deterministic execution graphs, workflows, state transitions | DAG traversal, state machine, rollback | Not agent (adaptive) — execution is deterministic |
| **DAG-Time-LD** | Temporal evolution, causality, version history, ordering | Causal ordering, version resolution | Not provenance (who/when) — time is structure of change |
| **DAG-Privacy-LD** | Selective disclosure, privacy-preserving semantics | Redaction, blinding, zero-knowledge transforms | Not security — privacy is about selective non-disclosure |
| **DAG-Stream-LD** | Real-time distributed state, event streams, continuous representation | Append-log semantics, conflict resolution | Not time (static) — stream is continuous and unbounded |
Better as Semantic Profiles (CSP)
These describe what is represented rather than requiring a new encoding or processing model. They belong as semantic profiles built on top of existing codec families:
| Concept | Home Codec Family | Reasoning |
|---|---|---|
| DAG-Meaning-LD | DAG-Reason-LD | Meaning is a reasoning output — inference about semantics |
| DAG-Elements-LD | DAG-Constitution-LD | Elements are governance components — belong in constitutional semantics |
| DAG-Factors-LD | DAG-Reason-LD or URS Group | Factors are analytical decompositions — representable as URS Groups |
| DAG-Effects-LD | DAG-Time-LD | Effects are temporal outcomes — belong in temporal semantics |
| DAG-Dynamics-LD | DAG-Stream-LD | Dynamics are stream patterns — belong in stream semantics |
Interoperability Rules
1. All codecs preserve URS invariants (I1–I23). A codec that violates an invariant is not a URS codec. 2. Cross-codec conversion is lossless within the same representation class. A DAG-Trust-LD attestation decoded to URS and re-encoded as DAG-Constitution-LD loses trust semantics unless the target codec declares support for that profile. 3. Semantic profiles are additive — a codec MAY carry multiple profiles. A DAG-Constitution-LD document MAY also be a DAG-Trust-LD attestation if it declares both profiles. 4. Unknown profiles are preserved opaquely — a codec implementation MUST NOT drop semantic fields it does not understand. Silently dropping profile semantics is a conformance violation. 5. Codec families are independent — the decision to use DAG-Constitution-LD does not require DAG-Trust-LD, and vice versa. Families compose at the profile level. 6. Provenance survives encoding — every representation retains its URS provenance regardless of codec choice. Changing codec does not reset provenance.
Development Order
1. DAG-JSON-LD — first codec (proves architecture, provides reference). Immediate. 2. DAG-Constitution-LD — governance attaches to representation. Next. 3. DAG-Trust-LD — trust builds on constitutional identity. Follows. 4. DAG-Time-LD — time is prerequisite for most stateful profiles. Parallel. 5. DAG-Exec-LD — workflow from constitutional governance. Next. 6. DAG-Reason-LD — reasoning on verified trust. Next. 7. DAG-Agent-LD — agents on reasoning + execution. Next. 8. DAG-Proof-LD — formal verification matures early but is specified late (requires settled semantics). 9. DAG-Privacy-LD — privacy on established data formats. Last fundamental. 10. DAG-Stream-LD — continuous representation on static foundation. Last.
Semantic profiles (CSP) are developed alongside their home codecs, not after.
Relationship to Existing Ecosystems
| Ecosystem | CCA Relationship |
|---|---|
| IPLD | URS is the data model; IPLD codecs (DAG-JSON, DAG-CBOR) are valid URS codecs under the IPLD Compatibility Profile (URS §7.1) |
| RDF/OWL | An RDF Compatibility Profile maps URS Entities to RDF triples. URS Properties become RDF predicates; URS Links become RDF reification. |
| Unicode | URS strings use Unicode. URS does not define character representation — that is Unicode's constitutional role at the character layer. |
| JSON-LD | URS uses JSON-LD 1.1 framing as the default encoding for all DAG-*-LD families. The `@context` maps URS representation kinds to IRIs. |
Governance
- Codec family specs are frozen constitutional artifacts (same process as URS).
- Semantic profiles are live documents — register them in the CSP registry, update as needed, version semantically.
- Ontologies are ungoverned — communities define their own.
- New codec family proposals must pass the constitutional filter (§CCA What to Build When) and be approved through the ICore governance process.
- Codec conformance suites are mandatory for every codec family. A family without a conformance suite is draft status, not frozen.
End of CCA Framework v0.1.0