https://github.com/mempalace/mempalace
The best-benchmarked open-source AI memory system. And it's free.
https://github.com/mempalace/mempalace
ai chromadb llm mcp memory python
Last synced: about 6 hours ago
JSON representation
The best-benchmarked open-source AI memory system. And it's free.
- Host: GitHub
- URL: https://github.com/mempalace/mempalace
- Owner: MemPalace
- License: mit
- Created: 2026-04-05T01:12:07.000Z (20 days ago)
- Default Branch: develop
- Last Pushed: 2026-04-21T04:47:58.000Z (4 days ago)
- Last Synced: 2026-04-21T06:42:01.123Z (4 days ago)
- Topics: ai, chromadb, llm, mcp, memory, python
- Language: Python
- Homepage: http://mempalaceofficial.com/
- Size: 15.1 MB
- Stars: 48,552
- Watchers: 294
- Forks: 6,358
- Open Issues: 421
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Codeowners: .github/CODEOWNERS
- Security: SECURITY.md
- Roadmap: ROADMAP.md
- Agents: AGENTS.md
Awesome Lists containing this project
README
> [!CAUTION]
> **Scam alert.** The only official sources for MemPalace are this
> [GitHub repository](https://github.com/MemPalace/mempalace), the
> [PyPI package](https://pypi.org/project/mempalace/), and the docs site at
> **[mempalaceofficial.com](https://mempalaceofficial.com)**. Any other
> domain — including `mempalace.tech` — is an impostor and may distribute
> malware. Details and timeline: [docs/HISTORY.md](docs/HISTORY.md).
# MemPalace
Local-first AI memory. Verbatim storage, pluggable backend, 96.6% R@5 raw on LongMemEval — zero API calls.
[![][version-shield]][release-link]
[![][python-shield]][python-link]
[![][license-shield]][license-link]
[![][discord-shield]][discord-link]
---
## 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`](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](https://mempalaceofficial.com/concepts/the-palace.html).
---
## Install
```bash
pip install mempalace
mempalace init ~/projects/myapp
```
## Quickstart
```bash
# 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](https://mempalaceofficial.com/guide/getting-started.html).
---
## Benchmarks
All numbers below are reproducible from this repository with the commands
in [`benchmarks/BENCHMARKS.md`](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`](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:**
```bash
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](https://mempalaceofficial.com/concepts/knowledge-graph.html).
## 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](https://mempalaceofficial.com/reference/mcp-tools.html).
## 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](https://mempalaceofficial.com/concepts/agents.html).
## Auto-save hooks
Two Claude Code hooks save periodically and before context compression:
[mempalaceofficial.com/guide/hooks](https://mempalaceofficial.com/guide/hooks.html).
---
## 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
- Getting started → [mempalaceofficial.com/guide/getting-started](https://mempalaceofficial.com/guide/getting-started.html)
- CLI reference → [mempalaceofficial.com/reference/cli](https://mempalaceofficial.com/reference/cli.html)
- Python API → [mempalaceofficial.com/reference/python-api](https://mempalaceofficial.com/reference/python-api.html)
- Full benchmark methodology → [benchmarks/BENCHMARKS.md](benchmarks/BENCHMARKS.md)
- Release notes → [CHANGELOG.md](CHANGELOG.md)
- Corrections and public notices → [docs/HISTORY.md](docs/HISTORY.md)
## Contributing
PRs welcome. See [CONTRIBUTING.md](CONTRIBUTING.md).
## License
MIT — see [LICENSE](LICENSE).
[version-shield]: https://img.shields.io/badge/version-3.3.0-4dc9f6?style=flat-square&labelColor=0a0e14
[release-link]: https://github.com/MemPalace/mempalace/releases
[python-shield]: https://img.shields.io/badge/python-3.9+-7dd8f8?style=flat-square&labelColor=0a0e14&logo=python&logoColor=7dd8f8
[python-link]: https://www.python.org/
[license-shield]: https://img.shields.io/badge/license-MIT-b0e8ff?style=flat-square&labelColor=0a0e14
[license-link]: https://github.com/MemPalace/mempalace/blob/main/LICENSE
[discord-shield]: https://img.shields.io/badge/discord-join-5865F2?style=flat-square&labelColor=0a0e14&logo=discord&logoColor=5865F2
[discord-link]: https://discord.com/invite/ycTQQCu6kn