# Design History

This directory preserves the **design history** of HEXT — RFCs, pre-release drafts, and evolutionary context.

> **RFCs describe WHY.**  
> **[SPECIFICATION.md](../SPECIFICATION.md) defines WHAT.**

These documents are archived for academic citation, migration reference, and historical context. They are **not** the active normative standard.

---

## Archive Index

| Document | Version | Type | Description |
|---|---|---|---|
| [RFC-NVS20_v2_2_0-source.md](RFC-NVS20_v2_2_0-source.md) | 2.2.0 | RFC | RFC-NVS20 source — Semantic Object Graph architecture |
| [SPECIFICATION-v2.2.0-draft.md](SPECIFICATION-v2.2.0-draft.md) | 2.2.0 | Draft | Pre-1.0 repository specification draft |
| [SPEC-v0.1.0-markdown-ledger.md](SPEC-v0.1.0-markdown-ledger.md) | 0.1.0 | Legacy | Original `.hxt` Markdown-hosted ledger format |

---

## Evolution Timeline

```text
v0.1.0  Markdown-hosted ledger format
          │
v2.0.0  Five-field object model (object, provenance, semantic, ledger, final_seal)
          │
v2.1.0  Semantic XML as canonical serialization
          │
v2.2.0  Semantic Object Graph as canonical model (RFC-NVS20)
          │
v1.0.0  HEXT Standard 1.0 — first official public release (Stable)
```

---

## RFC Archive

RFCs (Request for Comments) in the HEXT ecosystem record architectural debates, design rationales, and evolutionary paths. They remain available as historical references.

| RFC | Title | Status |
|---|---|---|
| RFC-NVS20 | HEXT Crystallized Knowledge Object Container | Superseded by HEXT Standard 1.0 |

Future RFCs proposing standard changes follow the process in [HEXT-AI Governance](https://github.com/HEXT-AI/.github/blob/main/STANDARDS-PROCESS.md).

---

## Migration

For transition guidance from RFC-era documents to HEXT Standard 1.0, see [MIGRATION.md](../MIGRATION.md).

Legacy `.hxt` v0.1.0 documents remain valid under grandfather compatibility rules in [docs/canonicalization.md](../docs/canonicalization.md).

---

## Citation

When citing the active standard:

```text
HEXT-AI Organization. HEXT Standard 1.0: The Semantic Object Graph Standard.
Version 1.0.0, July 7, 2026. https://github.com/HEXT-AI/hxt-spec
```

When citing historical RFCs, include the RFC identifier and note supersession by HEXT Standard 1.0.