# MemPalace
Local-first AI memory. Verbatim storage, pluggable backend, 96.6% R@5 raw on LongMemEval — zero API calls.
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> [!CAUTION]
> **Beware of impostor sites.** MemPalace has no other official websites. The **only** official sources are this **[GitHub repository](https://github.com/MemPalace/mempalace)**, the **[PyPI package](https://pypi.org/project/mempalace/)**, and the docs at **[mempalaceofficial.com](https://mempalaceofficial.com)**. Any other domain (including `.tech`, `.net`, or other `.com` variants) is an impostor and may distribute malware. Details and timeline: [docs/HISTORY.md](docs/HISTORY.md).
> [!IMPORTANT]
> **Claude Code sessions expire in 30 days without auto-save hooks wired.** [Read this →](https://github.com/MemPalace/mempalace/discussions/1388)
>
> Need the shortest recovery/setup path? Use the [Claude Code retention setup checklist](https://mempalaceofficial.com/guide/claude-code-retention.html).
---
## 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
MemPalace ships a CLI, so install it in an isolated environment to avoid
PEP 668 errors on Debian/Ubuntu/Homebrew Pythons and to keep mempalace's
deps (`chromadb`, `numpy`, `grpcio`, …) from conflicting with anything
else in your global site-packages.
We recommend [`uv`](https://docs.astral.sh/uv/) — `uv tool install` puts
the `mempalace` CLI in an isolated environment on your PATH:
```bash
uv tool install mempalace
mempalace init ~/projects/myapp
```
[`pipx`](https://pipx.pypa.io/) works the same way if you prefer it:
`pipx install mempalace`.
Prefer plain `pip` only inside an activated virtualenv where you
explicitly want `import mempalace` available:
```bash
python -m venv .venv && source .venv/bin/activate
pip install mempalace
```
### Docker
A container image is also available for running the MCP server or the CLI
without a local Python toolchain. Everything persists under `/data` (palace,
config, and the cached embedding model), so mount a volume there.
```bash
# Build the image (CPU; bundles the `extract` + `spellcheck` extras)
docker build -t mempalace .
# MCP server over stdio — note the `-i` flag (JSON-RPC needs stdin)
docker run -i --rm -v mempalace-data:/data mempalace
# Run any CLI command instead (mount the host directory you want to mine)
docker run --rm -v mempalace-data:/data -v /path/to/project:/work mempalace mine /work
docker run --rm -v mempalace-data:/data mempalace search "why GraphQL"
```
Wire it into an MCP client (e.g. Claude Code) as a stdio server:
```json
{
"mcpServers": {
"mempalace": {
"command": "docker",
"args": ["run", "-i", "--rm", "-v", "mempalace-data:/data", "mempalace"]
}
}
}
```
`docker compose run --rm mcp` works too (see `docker-compose.yml`). For
CUDA-accelerated embeddings, build the GPU variant with
`docker build -f Dockerfile.gpu -t mempalace:gpu .` and run it with
`--gpus all`. Customise the bundled extras at build time, e.g.
`docker build --build-arg EXTRAS="extract,spellcheck" -t mempalace .`.
## Storage backends
ChromaDB is the default and needs no configuration. MemPalace also ships a
pluggable backend contract, exercised across deliberately different substrates
so the contract is never accidentally shaped around one vendor. Every
non-default backend is opt-in.
| Backend | Mode | Install | Namespaces | Lexical | Configure with |
| ------- | ---- | ------- | :--------: | :-----: | -------------- |
| `chroma` _(default)_ | Local (embedded) | bundled | – | ✓ | – |
| `sqlite_exact` | Local (exact) | bundled | – | ✓ | – |
| `milvus` | Local (Lite) · Server opt-in | `mempalace[milvus]` | ✓ | ✓ | `MEMPALACE_MILVUS_URI` |
| `qdrant` | Server (REST) | bundled | ✓ | ✓ | `MEMPALACE_QDRANT_URL` |
| `pgvector` | Server (Postgres) | `mempalace[pgvector]` | ✓ | ✓ | `MEMPALACE_PGVECTOR_DSN` |
Select with `--backend