Similar to #453

Thanks @web3guru888 — great comparison with #453. The overlap is real, so let me address the tradeoffs honestly.

Where #453 is better: JSONL per wing/room is genuinely more git-friendly and the mempalace backup command is good UX. For large palaces, streaming writes per-room avoids the single-large-file problem.

Where this PR is better: KG export (entities + triples), MCP tools, test coverage, and format versioning. As you noted, losing 710 entities and 1,014 triples on backup/restore would be painful.

JSONL streaming for large palaces — valid concern. A 39k-drawer palace would produce a large JSON file. For v1 I'll add a size estimate warning in the CLI output. Streaming JSONL for the drawers array is the right long-term fix, but it changes the format spec — better as a version 2.

Entity name collisions on import — noted. You're right that name-based triple import can mislink if two different entities share a name. The KG already normalizes IDs from names (alice = Alice), so this is only a problem across palaces with genuinely different entities sharing names. I'll add a TODO for ID-based import as a safety improvement.

Ideal outcome: Merge the best of both PRs. I'm happy to incorporate #453's JSONL per-room format for drawers while keeping the KG export, MCP tools, and test coverage from this PR. If @scokeepa and the maintainers are open to it, I can do the merge work.

— Gonzalo

The hybrid approach makes a lot of sense — JSONL per-room drawers for streaming + git-friendliness, KG export, MCP tools, and format versioning from this PR. That would be the best of both.

If @scokeepa and @milla-jovovich are open to a merge, it's worth a direct ping in #453 to propose the consolidation. Having two competing export PRs in review simultaneously is going to be hard for maintainers to untangle, and the community benefits from one well-designed export spec rather than two partial ones.

The ID-based triple import TODO is worth flagging in the code as a rather than just tracking it mentally — makes it visible to future contributors.

Hey @Nitrogonza9 — I'm the author of #453. The hybrid approach you proposed sounds great, I'm fully on board.

What I'd suggest:

• Use JSONL per wing/room from feat: add backup, export, and import commands #453 for drawers (git-friendly, streaming-safe for large palaces)
• Keep KG export (entities + triples), MCP tools (mempalace_export/mempalace_import), format versioning, and the test suite from this PR
• Keep mempalace backup (binary zip) and mine --backup from feat: add backup, export, and import commands #453 as the fast-restore track

This gives users two complementary workflows:

Happy to have you drive the merge work — you clearly have a good grasp of both PRs. I can review and test on my end once you have a combined branch. Let me know if you'd prefer to base it on #435 or #453, either works for me.

cc @milla-jovovich @bmaltais

@scokeepa @web3guru888 — hybrid branch ready for review:

Branch: `Nitrogonza9:feat/palace-export-import-v2`

What's in it

Two export tracks (auto-detected from output path):
```bash
mempalace export backup.json # single JSON file (drawers + KG)
mempalace export ./sync/ # JSONL per wing/room (git-friendly)
mempalace export ./sync --format jsonl # explicit override
```

Binary backup track (from #453):
```bash
mempalace backup # directory copy
mempalace backup --zip # zip archive
mempalace backup --max-backups 3
```

Three MCP tools: `mempalace_export`, `mempalace_import`, `mempalace_backup` — all auto-detect format.

Code attribution

• `backup_palace()` and the JSONL export/import structure adapted from @scokeepa's feat: add backup, export, and import commands #453
• KG export, single-JSON format, format versioning, auto-detection, and the test suite from this PR
• @scokeepa is credited as co-author in the commit

Tests

26 tests covering both formats, auto-detection, backup, round-trip, and KG preservation. Full suite passing. Ruff clean. Zero new dependencies.

Happy to:

1. Open this as a new PR replacing both feat: palace export/import for backup and migration #435 and feat: add backup, export, and import commands #453
2. Or push it onto either existing branch

Whichever the maintainers prefer. cc @milla-jovovich @bmaltais

— Gonzalo

@Nitrogonza9 — just reviewed the feat/palace-export-import-v2 branch. The hybrid design is solid and the auto-detection is a nice touch. A few things I'd like to see before this goes up as a new PR:

1. Backup integrity validation (from #448 feedback)

After a zip backup, we should verify the archive isn't corrupted. At minimum:

• Verify SQLite file passes PRAGMA integrity_check
• Verify HNSW index file exists in the archive

A corrupted backup that passes silently is worse than no backup. Something like:

def _validate_backup(backup_path: Path, zip_mode: bool) -> list[str]:
    """Quick integrity check after backup."""
    errors = []
    if zip_mode:
        import zipfile
        try:
            with zipfile.ZipFile(backup_path, 'r') as zf:
                bad = zf.testzip()
                if bad:
                    errors.append(f"Corrupt file in archive: {bad}")
                names = zf.namelist()
                if not any('chroma.sqlite3' in n for n in names):
                    errors.append("SQLite file missing from backup")
        except Exception as e:
            errors.append(f"Archive validation failed: {e}")
    return errors

2. Embedding not included — add user-visible note

The JSONL and JSON exports don't include embedding vectors. On import, ChromaDB re-embeds everything, which is slow for large palaces and produces different vectors if the embedding model changes. Worth adding a note in the CLI output:

Note: embeddings are not included. Import will re-embed using the configured model.

3. max_backups in config (from #448 feedback)

Right now max_backups is only a function parameter / CLI flag. Users with large palaces may want to set this once in config.json rather than passing --max-backups every time. A backup.max_retained field in MempalaceConfig would be ideal.

4. KG triple import — entity name collision TODO

You mentioned this earlier — the add_triple(triple["subject"], ...) approach can mislink if two different entities share a name across palaces. Worth adding a # TODO: ID-based triple import for cross-palace safety in the code so future contributors can find it.

Happy to help test once these are addressed. Looking forward to the consolidated PR.

@Nitrogonza9 — the consolidated design looks right to me. The auto-detection from output path is clean; users shouldn't have to think about format flags unless they want to override.

A few observations from our side:

Export format choice: The JSONL-per-wing approach is compelling for large palaces (ours has 710 KG entities across 5 wings). Diff-friendly exports matter a lot when you're syncing state across environments or doing incremental backups alongside git-tracked content. Good call making it the path-based default.

KG round-trip correctness: @scokeepa's point about entity name collisions on import is the right call to flag. We ran into a similar edge case when importing across wings — subject/object names that are unique within one palace aren't guaranteed globally. A # TODO marker is fine for now; the current use case (single-palace backup/restore) is the common path.

Backup validation: Strongly agree with the post-backup integrity check. A corrupt zip that reports success is a genuinely bad failure mode. The zipfile.testzip() approach is the right lightweight check — we use a similar pattern before trusting any state snapshots.

Missing embedding note: Good suggestion from @scokeepa. Worth surfacing this in the CLI output, especially if the import is going into a new palace with a different default model configured. Re-embedding is usually fine but users need to know it's happening.

On the PR structure: if you're opening a new consolidated PR, I'd vote for that over trying to merge into either existing branch — the combined design is clearly better than either standalone approach. Would make reviewing cleaner too.

Happy to test the round-trip when the new PR is up.

Closing — this is superseded by recently merged PRs to develop. Thank you for the contribution!