# Archive Report: obsidian-plugin

## Change Summary

| Field | Value |
|-------|-------|
| **Change** | obsidian-plugin |
| **Date Archived** | 2026-04-06 |
| **Archive Path** | `openspec/changes/archive/2026-04-06-obsidian-plugin/` |
| **Status** | ✅ COMPLETE |

---

## Implementation Results

| Metric | Value |
|--------|-------|
| Tasks completed | 27/27 (100%) |
| Phases | 5/5 |
| New tests | 39 |
| Test suite (packages) | 10/10 green |
| Live smoke test | 1,731 observations + 277 hubs exported successfully |

---

## Specs Synced to Main

| Domain | Action | Target Path |
|--------|--------|-------------|
| `obsidian-export` | **Created** (9 requirements, 23 scenarios) | `openspec/specs/obsidian-export/spec.md` |
| `obsidian-plugin` | **Created** (5 requirements, 10 scenarios) | `openspec/specs/obsidian-plugin/spec.md` |

Both domains were new (no prior main specs existed). Delta specs were full specs — copied directly.

---

## Files Archived

| File | Description |
|------|-------------|
| `proposal.md` | Intent, scope, approach, capabilities, rollback plan |
| `specs/obsidian-export/spec.md` | Go CLI exporter — 9 requirements (REQ-EXPORT-01 through REQ-EXPORT-09) |
| `specs/obsidian-plugin/spec.md` | TypeScript Obsidian plugin — 5 requirements (REQ-PLUGIN-01 through REQ-PLUGIN-05) |
| `design.md` | Technical architecture — package layout, data types, vault structure, slug algorithm, incremental sync algorithm, TypeScript plugin architecture, testing strategy, key decisions |
| `tasks.md` | 27 tasks across 5 phases (all marked ✅) |

---

## Engram Observation IDs (Audit Trail)

| Artifact | Observation ID | Topic Key |
|----------|---------------|-----------|
| Proposal | #1718 | `sdd/obsidian-plugin/proposal` |
| Spec | #1719 | `sdd/obsidian-plugin/spec` |
| Design | #1723 | `sdd/obsidian-plugin/design` |
| Tasks | #1724 | `sdd/obsidian-plugin/tasks` |
| Apply Progress (all phases) | #1734 | `sdd/obsidian-plugin/apply-progress` |
| Implementation Complete | #1739 | `sdd/obsidian-plugin/implementation-complete` |
| Archive Report | (this) | `sdd/obsidian-plugin/archive-report` |

---

## Source of Truth Updated

The following specs now reflect the implemented behavior:
- `openspec/specs/obsidian-export/spec.md` — CLI exporter specification (212 lines, 9 requirements)
- `openspec/specs/obsidian-plugin/spec.md` — TypeScript plugin specification (130 lines, 5 requirements)

---

## New Code Delivered

| Path | Description |
|------|-------------|
| `internal/obsidian/slug.go` | Slugify function — collision-safe filename generation |
| `internal/obsidian/slug_test.go` | TestSlugify (9 cases) |
| `internal/obsidian/markdown.go` | ObservationToMarkdown — YAML frontmatter + body + wikilinks |
| `internal/obsidian/markdown_test.go` | TestObservationToMarkdown (4 cases) |
| `internal/obsidian/state.go` | SyncState read/write, ExportResult types |
| `internal/obsidian/state_test.go` | TestSyncStateRoundTrip |
| `internal/obsidian/hub.go` | SessionHubMarkdown, TopicHubMarkdown |
| `internal/obsidian/hub_test.go` | TestSessionHub, TestTopicHub, TestTopicHubSkipped |
| `internal/obsidian/exporter.go` | Exporter struct, StoreReader interface, Export() with incremental/delete/filter |
| `internal/obsidian/exporter_test.go` | Full pipeline integration tests (20+ cases) |
| `cmd/engram/main.go` | `obsidian-export` switch case + cmdObsidianExport() |
| `plugin/obsidian/manifest.json` | Obsidian plugin manifest |
| `plugin/obsidian/package.json` | Node dependencies + build scripts |
| `plugin/obsidian/tsconfig.json` | TypeScript config |
| `plugin/obsidian/esbuild.config.mjs` | ESBuild → CJS bundler config |
| `plugin/obsidian/src/settings.ts` | EngramSettings interface, EngramSettingTab class |
| `plugin/obsidian/src/sync.ts` | HTTP sync client — GET /export, diff, vault.create/modify/delete |
| `plugin/obsidian/src/main.ts` | EngramBrainPlugin class — ribbon, status bar, polling |
| `README.md` | New Obsidian Export section with usage, flags, vault diagram |

---

## Key Technical Learnings

- **StoreReader interface** — thin adapter needed (Stats() signature mismatch with `*store.Store`); narrow interface enabled clean test mocking
- **CJS format required** — Obsidian plugins must bundle as CommonJS, not ESM; esbuild `format: 'cjs'`
- **topic_key hierarchy** — prefix grouping (splitting on last `/`) gives connected graph clusters for free without embeddings
- **Hub threshold ≥2** — prevents orphan hub pages cluttering the Obsidian graph view
- **Engram wins** — one-way mirror design eliminates all conflict resolution complexity

---

## SDD Cycle Complete

The change has been fully planned, implemented, verified, and archived.

```
Propose → Spec → Design → Tasks → Apply → Verify → Archive ✅
```

Ready for the next change.
