Janus Stack (Architecture)

Janus is a governance kernel and layered architecture for auditable systems operating in AI-assisted environments.

This non-normative Framework document describes the conceptual separation of layers. Janus Core Lite v0.2 Draft is the normative source.

Any MUST/SHOULD/MAY language here is Framework guidance and does not add to or alter Core requirements.

Layer separation

Janus is structured as a set of layers with explicit responsibilities.

Core

Location: core/

Core defines:

• Canonical terms and semantics defined by Janus Core Lite v0.2
• Protocols and policy primitives
• Canonical log types and event identifiers (e.g., MANAGEMENT_LOG, SCHEMA_LOG, AUDIT_LOG, OMISSION_DETECTED)

Core does not define:

• Runtime technologies, vendors, or deployment assumptions
• Storage engines, network transports, or UI constraints

Framework

Location: framework/

Framework defines:

• Reusable governance mechanisms that compose with Core semantics
• Gate patterns (gates) and reference models that constrain transitions and outputs

Framework should remain compatible with multiple runtimes.

Runtimes

Location: runtimes/

Runtimes:

• Execute workflows that implement Core and Framework requirements
• Produce and consume records that conform to Core-defined semantics

Runtimes MUST NOT redefine Core meanings.

Adapters

Location: adapters/

Adapters:

• Map runtime interfaces to external storage/transport surfaces
• Preserve the meaning of canonical records while providing interoperability

Adapters MUST document any lossy mapping.

SDK

Location: sdk/

SDKs:

• Provide developer-facing helpers to integrate with a Janus runtime or adapter
• Improve ergonomics without altering Core semantics

Knowledge spaces

The repository separates normative specifications from supporting material.

• docs/: Non-normative Framework interpretation and guidance, subordinate to Janus Core Lite v0.2.
• papers/: Background analysis and research notes. Non-normative by default.
• studies/: Experiments, logs, and results. Non-normative by default.
• philosophy/: Canon and essays. Non-normative by default.

No published Framework document supersedes or extends the normative Core.

Semantic stability rule (Core-first)

Janus Core Lite v0.2 is the source of semantic truth. The published glossary is a subordinate, non-normative aid.

Rules: 1) Framework, Runtime, Adapter, and SDK terminology should remain aligned with the Core. 2) Changing the Framework glossary should trigger review of dependent Framework documents. 3) When a conflict is discovered, the Framework material should be corrected to match the Core.

This rule is intended to keep semantics stable while allowing implementations to evolve independently.