Context Object Specification (COS)

Version: 0.2
Chapter: 260 — Metadata
Status: Informative — Supporting
Category: Core Model

1. Purpose

This chapter defines metadata guidance for the Context Object Specification (COS).

In COS v0.2 lean core, metadata is intentionally small.

It exists purely for observability, traceability, and versioning.

It does NOT describe content meaning.

2. Conceptual Role

If:

• Semantic = meaning
• Recommendation = action possibility

Then:

Metadata = system-level truth about the Context Object itself

It answers:

“How was this Context Object created and transformed?”

3. Definition

Metadata is a structured, non-semantic layer that describes the lifecycle and provenance of a Context Object.

It is independent of:

• content
• structure
• semantic interpretation
• recommendations

4. Core Principle

Metadata is:

about the system, not about the content

This principle enforces strict separation between:

• content understanding
• system observability

5. Lean Meta Model

interface Meta {
  createdAt?: number;
  adapter?: string;
  stages?: string[];
}

createdAt is an integer count of milliseconds since the Unix epoch.

Detailed source information belongs to the top-level source field.

stages MAY list minimal generation stages such as:

["selection", "source", "context", "relations"]

stages is not a detailed pipeline trace. It exists only to indicate which major parts of the lean object were produced.

Detailed pipeline traces and integrity data SHOULD be placed in Extensions.

6. Extended Metadata (Optional)

Implementations MAY expose extended metadata for debugging or audit use cases.

interface ExtendedMetadata {
  pipeline?: PipelineTrace;
  integrity?: IntegrityInfo;
}

7. Pipeline Trace

Represents how the Context Object was transformed.

interface PipelineTrace {
  stages: PipelineStageTrace[];
}

interface PipelineStageTrace {
  name: string;
  timestamp?: number;
  durationMs?: number;
  status?: "success" | "failed" | "skipped";
}

8. Integrity Information

Optional verification and consistency metadata.

interface IntegrityInfo {
  hash?: string;
  checksumAlgorithm?: "sha256";
  validated?: boolean;
}

9. Immutability Rule

Metadata MUST reflect the history of a Context Object.

It MUST NOT be used to modify or reinterpret:

• semantic content
• hierarchy structure
• recommendations

10. Observability Principle

Metadata MUST enable:

• debugging pipeline execution
• tracing transformation stages
• verifying data consistency
• reproducing Context Object generation

11. Non-Semantic Constraint

Metadata MUST NOT include:

• content interpretation
• semantic labeling
• user intent inference
• recommendation logic

It is strictly system-level.

12. Relationship to Context Object

Meta is an optional top-level component of the Context Object:

Context Object
   ├── source
   ├── selection
   ├── context
   └── meta?

13. Determinism Note

Metadata MAY include non-deterministic fields (e.g., timestamps).

However:

• pipeline trace SHOULD be reproducible
• structural metadata SHOULD remain consistent across runs

14. Example (Informative)

{
  "createdAt": 1720250000000,
  "adapter": "web-adapter",
  "stages": ["selection", "source", "context"]
}

15. Design Notes

Metadata is deliberately kept outside content context to avoid:

• mixing system telemetry with content meaning
• contaminating Consumer reasoning with execution details
• coupling protocol with implementation internals

It ensures COS remains both interpretable and debuggable at scale.

16. Summary

Metadata defines optional system-level facts about a Context Object.

It provides limited observability without interfering with source, selection, or context interpretation.

Detailed observability belongs in Extensions.