jp e5e7a57930 fix(hnsw): gate quarantine_stale_hnsw to cold-start, not every reconnect
Symptom on the canonical disks daemon: drift quarantines firing every
10–30 minutes throughout the day under steady write load. Logs show
.drift-* directories accumulating despite the daemon being the only
writer (no Syncthing replication of palace data).

Root cause is a false-positive thrash in the quarantine heuristic:

- chroma.sqlite3 mtime bumps on every write (millisecond cadence).
- HNSW segment files (data_level0.bin) only flush to disk on
  chromadb's internal cadence, which can lag minutes behind sqlite
  under continuous write load.

Once the gap exceeds the 300s threshold, quarantine_stale_hnsw renames
a perfectly valid HNSW segment, chromadb rebuilds it from scratch, and
the cycle repeats as soon as the next batch of writes lands. The 300s
threshold (lowered from 3600s in PR #1173 after a 0.96h-drift production
segfault) is correct for the cross-machine-replication failure mode it
was designed for, but wrong for a daemon-strict deployment whose only
"drift" source is its own benign flush lag.

Fix: gate the proactive quarantine check to the first ``make_client()``
invocation per palace per process (``ChromaBackend._quarantined_paths``
set). Real cold-start drift (replication, partial restore, crashed-mid-
write) still gets caught — that's exactly when a fresh daemon process
opens the palace. Real runtime drift on observed HNSW errors still gets
caught via palace-daemon's ``_auto_repair`` which calls
``quarantine_stale_hnsw`` directly, bypassing this gate.

Two new tests in test_backends.py verify single-fire-per-palace and
per-palace independence. Conftest clears the gate between tests.

Suite 1362/1362 pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-26 09:40:25 -07:00
2026-04-23 16:44:22 -07:00
2026-04-23 16:44:22 -07:00
2026-04-16 21:46:03 -03:00

Caution

Scam alert. The only official sources for MemPalace are this GitHub repository, the PyPI package, and the docs site at mempalaceofficial.com. Any other domain — including mempalace.tech — is an impostor and may distribute malware. Details and timeline: docs/HISTORY.md.

MemPalace

MemPalace

Local-first AI memory. Verbatim storage, pluggable backend, 96.6% R@5 raw on LongMemEval — zero API calls.


What it is

MemPalace stores your conversation history as verbatim text and retrieves it with semantic search. It does not summarize, extract, or paraphrase. The index is structured — people and projects become wings, topics become rooms, and original content lives in drawers — so searches can be scoped rather than run against a flat corpus.

The retrieval layer is pluggable. The current default is ChromaDB; the interface is defined in mempalace/backends/base.py and alternative backends can be dropped in without touching the rest of the system.

Nothing leaves your machine unless you opt in.

Architecture, concepts, and mining flows: mempalaceofficial.com/concepts/the-palace.


Install

pip install mempalace
mempalace init ~/projects/myapp

Quickstart

# Mine content into the palace
mempalace mine ~/projects/myapp                    # project files
mempalace mine ~/.claude/projects/ --mode convos   # Claude Code sessions (scope with --wing per project)

# Search
mempalace search "why did we switch to GraphQL"

# Load context for a new session
mempalace wake-up

For Claude Code, Gemini CLI, MCP-compatible tools, and local models, see mempalaceofficial.com/guide/getting-started.


Benchmarks

All numbers below are reproducible from this repository with the commands in benchmarks/BENCHMARKS.md. Full per-question result files are committed under benchmarks/results_*.

LongMemEval — retrieval recall (R@5, 500 questions):

Mode R@5 LLM required
Raw (semantic search, no heuristics, no LLM) 96.6% None
Hybrid v4, held-out 450q (tuned on 50 dev, not seen during training) 98.4% None
Hybrid v4 + LLM rerank (full 500) ≥99% Any capable model

The raw 96.6% requires no API key, no cloud, and no LLM at any stage. The hybrid pipeline adds keyword boosting, temporal-proximity boosting, and preference-pattern extraction; the held-out 98.4% is the honest generalisable figure.

The rerank pipeline promotes the best candidate out of the top-20 retrieved sessions using an LLM reader. It works with any reasonably capable model — we have reproduced it with Claude Haiku, Claude Sonnet, and minimax-m2.7 via Ollama Cloud (no Anthropic dependency). The gap between raw and reranked is model-agnostic; we do not headline a "100%" number because the last 0.6% was reached by inspecting specific wrong answers, which benchmarks/BENCHMARKS.md flags as teaching to the test.

Other benchmarks (full results in benchmarks/BENCHMARKS.md):

Benchmark Metric Score Notes
LoCoMo (session, top-10, no rerank) R@10 60.3% 1,986 questions
LoCoMo (hybrid v5, top-10, no rerank) R@10 88.9% Same set
ConvoMem (all categories, 250 items) Avg recall 92.9% 50 per category
MemBench (ACL 2025, 8,500 items) R@5 80.3% All categories

We deliberately do not include a side-by-side comparison against Mem0, Mastra, Hindsight, Supermemory, or Zep. Those projects publish different metrics on different splits, and placing retrieval recall next to end-to-end QA accuracy is not an honest comparison. See each project's own research page for their published numbers.

Reproducing every result:

git clone https://github.com/MemPalace/mempalace.git
cd mempalace
pip install -e ".[dev]"
# see benchmarks/README.md for dataset download commands
python benchmarks/longmemeval_bench.py /path/to/longmemeval_s_cleaned.json

Knowledge graph

MemPalace includes a temporal entity-relationship graph with validity windows — add, query, invalidate, timeline — backed by local SQLite. Usage and tool reference: mempalaceofficial.com/concepts/knowledge-graph.

MCP server

29 MCP tools cover palace reads/writes, knowledge-graph operations, cross-wing navigation, drawer management, and agent diaries. Installation and the full tool list: mempalaceofficial.com/reference/mcp-tools.

Agents

Each specialist agent gets its own wing and diary in the palace. Discoverable at runtime via mempalace_list_agents — no bloat in your system prompt: mempalaceofficial.com/concepts/agents.

Auto-save hooks

Two Claude Code hooks save periodically and before context compression: mempalaceofficial.com/guide/hooks.


Requirements

  • Python 3.9+
  • A vector-store backend (ChromaDB by default)
  • ~300 MB disk for the default embedding model

No API key is required for the core benchmark path.

Docs

Contributing

PRs welcome. See CONTRIBUTING.md.

License

MIT — see LICENSE.

S
Description
Server-mode fork of MemPalace — shared Docker container on Unraid so Claude Code, Codex, and MCP clients can share one persistent AI memory palace over LAN
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