Local-first AI memory distributed as a Python CLI/library plus an MCP server. Stores conversation and project history as verbatim text — it explicitly does not summarize, extract, or paraphrase — and retrieves it with semantic search over a structured index where people/projects are 'wings', topics are 'rooms', and original content lives in 'drawers' so searches can be scoped rather than run flat. Bundles a temporal entity-relationship knowledge graph with validity windows.
- Storage
- Verbatim drawers indexed in a pluggable vector backend (ChromaDB by default; sqlite_exact for local exact-vector checks, plus opt-in Qdrant and pgvector backends behind a single storage contract). A temporal entity-relationship knowledge graph is backed by local SQLite. Nothing leaves the machine unless an external backend is explicitly configured.
- Retrieval
- Semantic search scoped by wing/room, with an optional hybrid pipeline (keyword boosting, temporal-proximity boosting, preference-pattern extraction) and an optional LLM-reranker over the top-20 retrieved sessions. The raw semantic path requires no API key, no cloud, and no LLM.
- Self-host
- Self-host: trivial
- License
- MIT
- Pricing
- Open-source (MIT) Python package, free to self-host; raw semantic retrieval needs no API key or cloud. Docs at mempalaceofficial.com; no paid tier identified. · Free / OSS
- GitHub stars
- 58,269
- Last release
- 2026-07-17
- Last commit
- 2026-08-08
- First catalogued
- 2026-06-28
Strengths
- Verbatim, no-extraction storage — the original text is never paraphrased away, so retrieval is auditable against the source
- Structured palace index (wings/rooms/drawers) lets searches be scoped instead of run against a flat corpus, plus a temporal SQLite knowledge graph
- Pluggable vector backend (ChromaDB default; sqlite_exact, Qdrant, pgvector, and an opt-in Milvus backend added in v3.6.0) and a 36-tool MCP server; raw semantic recall runs with no API key or cloud
- v3.6.0 (2026-07-17) added a secure-by-default `mempalace serve` remote/team server (TLS, bearer-token auth, read-only mode, Docker Compose/systemd templates) — a real step past single-machine-only deployment
Watch out
- README headlines self-reported retrieval benchmarks (96.6% R@5 raw / 98.4% held-out on LongMemEval, plus LoCoMo/ConvoMem/MemBench) — record those via harvest-benchmarks with selfReported:true, not on this card
- Very high star count (~57k) accumulated fast for a young project (created 2026-04); the README itself warns of impostor domains, so treat third-party mirrors with care
- Hybrid/rerank quality figures are vendor-reproducible but not independently audited
- Concurrent writers to the same palace remain restricted: v3.5.0 made the MCP server refuse a second writer rather than race the HNSW handle, and while v3.6.0 added writer-lease recovery and a 'shared daemon write-routing policy' to route writers toward one local daemon, Issue #1646's original ask (multi-agent-safe concurrent writing) is still open as of 2026-07-23
Best for
- Local-first agent memory where verbatim, source-traceable recall and scoped semantic search matter more than fact extraction
How it integrates
Benchmark results
No sourced results yet.
Sources
- Monthly card re-verification — GitHub API repo metadata: 57,938 stars, license MIT confirmed, archived=false, last commit on the default branch 2026-07-22 (third-party)
- MemPalace README (vendor)
- GitHub API repo metadata (stars, MIT license, v3.5.0 release) (third-party)
- PyPI — mempalace v3.5.0 (CLI/library package page) (third-party)
- MemPalace v3.5.0 release notes (2026-06-23) — 'Opt-in HTTP transport for the MCP server': `mempalace-mcp --transport http` serves JSON-RPC at `POST /mcp` (with `GET /healthz`); stdio remains the default; binds 127.0.0.1; optional bearer token. Same release: 'The MCP server refuses a second writer for the same palace' (#1818, #1823) (vendor)
- GitHub Issue #1646 — SSE/HTTP transport feature request, re-checked 2026-07-23: still open. The transport shipped separately in v3.5.0/v3.6.0; the issue's multi-agent-safe requirement remains unmet (vendor)
- MemPalace v3.6.0 release notes (2026-07-17) — 'secure remote serving, temporal facts, and resilient recovery': turnkey `mempalace serve` (TLS, bearer-token default, read-only mode, Docker Compose/systemd templates), opt-in Milvus storage backend, atomic knowledge-graph fact supersession, writer-lease recovery, 36-tool MCP surface (vendor)
- GitHub API re-check — 57656 stars, MIT, not archived, pushed 2026-07-22, latest release v3.6.0 (third-party)
- PyPI JSON API — mempalace 3.6.0 is the current published version (third-party)
- mempalaceofficial.com re-check — marketing/docs site, no pricing/plans page found; product remains free OSS with no paid tier (vendor)
Last verified 2026-08-01 · updated by refresh-framework-cards