# Archive Report: obsidian-auto-sync

**Archived**: 2026-04-06
**Project**: engram
**Change**: obsidian-auto-sync — graph config bootstrap + watch mode daemon

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## Summary

Completed SDD cycle for the `obsidian-auto-sync` change, which extends `engram obsidian-export` with two new capabilities:
1. **Graph config bootstrap** — automatically writes an Obsidian-opinionated `graph.json` to the vault on first run (preserve/force/skip modes)
2. **Watch-mode daemon** — keeps the vault in sync without external cron/launchd via `--watch` + `--interval`

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## Engram Observation IDs (Audit Trail)

| Phase | Topic Key | Observation ID |
|-------|-----------|----------------|
| Proposal | `sdd/obsidian-auto-sync/proposal` | #1742 |
| Spec | `sdd/obsidian-auto-sync/spec` | #1744 |
| Design | `sdd/obsidian-auto-sync/design` | #1745 |
| Tasks | `sdd/obsidian-auto-sync/tasks` | #1746 |
| Implementation Complete | `sdd/obsidian-auto-sync/implementation-complete` | #1748 |
| Archive Report | `sdd/obsidian-auto-sync/archive-report` | (saved at archive time) |

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## Specs Synced

| Domain | Action | Details |
|--------|--------|---------|
| `obsidian-export` | Created (merged) | REQ-EXPORT-01..09 from obsidian-plugin + REQ-GRAPH-01..06 + REQ-WATCH-01..07 = 16 requirements total |

**Source of truth**: `openspec/specs/obsidian-export/spec.md`

Delta applied from: `openspec/changes/archive/2026-04-06-obsidian-auto-sync/specs/obsidian-export/spec.md`

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## Archive Contents

| File | Status |
|------|--------|
| `proposal.md` | ✅ |
| `design.md` | ✅ |
| `specs/obsidian-export/spec.md` | ✅ (delta spec) |
| `tasks.md` | ✅ (21/21 tasks complete) |
| `archive-report.md` | ✅ (this file) |

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## Implementation Summary

**Tasks**: 21/21 complete (5 phases: Graph Config Bootstrap, Exporter Integration, Watcher, CLI Wiring, Documentation)

**Tests added**:
- `internal/obsidian`: 47 tests (was 33, +14 new)
- `cmd/engram`: 25 tests (was 18, +7 new)
- Full suite: 10 packages, zero regressions

**Files changed**:
- `internal/obsidian/graph.go` + `graph.json` + `graph_test.go` — NEW
- `internal/obsidian/watcher.go` + `watcher_test.go` — NEW
- `internal/obsidian/exporter.go` — Modified (GraphConfig field + SetGraphConfig/GraphConfig methods)
- `cmd/engram/main.go` — Modified (3 new flags, signal handling, watcher dispatch)
- `cmd/engram/main_test.go` — Modified (7 new test cases)
- `README.md` — Modified (flags table + Auto-sync section)

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## Live Smoke Test Results (2026-04-06)

| Scenario | Result |
|----------|--------|
| `--graph-config force` overwrites `graph.json` with exact user values (6 groups, correct forces) | ✅ |
| `--interval 5m` without `--watch` → error + exit 1 | ✅ |
| `--watch --interval 30s` → error "must be at least 1m" + exit 1 | ✅ |
| `--watch --interval 1m` → immediate first cycle, clean signal shutdown | ✅ |

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## Key Design Decisions

| Decision | Choice | Rationale |
|----------|--------|-----------|
| Default graph-config mode | `preserve` | Safe default; respects any existing user customization |
| `GraphConfig` zero value | `GraphConfigSkip` (not Preserve) | Backward compat with existing exporter tests that have no `.obsidian/` expectations |
| Graph config in watch loop | First cycle only | Prevents clobbering user mid-session customizations even in force mode |
| Embedded template | `//go:embed graph.json` | Versioned with binary; zero runtime deps; CGO_ENABLED=0 compatible |
| Signal handling | `signal.NotifyContext` | Go 1.16+ idiom; context propagates naturally to select block |
| Error handling in loop | Log + continue | Transient store/FS errors shouldn't kill a long-running daemon |

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## SDD Cycle Status

- [x] Proposal
- [x] Spec
- [x] Design
- [x] Tasks
- [x] Apply (21/21)
- [x] Verify (inline smoke test, all 10 packages green)
- [x] Archive ← **you are here**

**SDD cycle complete. Ready for next change.**
