Mnemosyne

The Context Engine for AI Agents — Give your AI agents persistent, observable, compliant memory.

All memories are plain markdown files you own. Search by meaning, traverse relationships, schedule reminders, and protect against poisoned data.

Python PostgreSQL License

⚠️ Rebrand Notice

This project was formerly known as Mnemosyne. We rebranded to Palimpsest in July 2026 to avoid confusion with an unrelated project that adopted the same name.

Why Palimpsest? A palimpsest is a manuscript on which later writing has been superimposed on earlier writing — yet traces of the original remain. It's the perfect metaphor for layered, persistent, evolving memory.

What is Palimpsest?

Palimpsest is a production-grade memory platform for AI agents. Unlike simple chat history or RAG, it gives agents:

• Long-term persistent memory — survives restarts, works across sessions
• Semantic search — find ideas by meaning, not just keywords
• Graph memory — notes link via [[wiki-links]], traverse relationships
• Security gates — injection detection, contradiction flagging, near-duplicate checks
• Prospective memory — "remind me in 3 days" — and it actually happens
• Sleep consolidation — nightly maintenance: archive stale, merge duplicates
• MCP server — Claude Code, Cursor, any MCP client can read/write memory
• Observability — audit trails, contamination detection, memory health dashboard
• Compliance — GDPR Article 17, EU AI Act ready

Architecture

┌─────────────────────────────────────────────┐
│  Your Question                              │
│  "What did we decide about API rate limit?" │
└──────────────────┬──────────────────────────┘
                   │
┌──────────────────▼──────────────────────────┐
│  Palimpsest Memory Platform               │
│  ┌──────────┐ ┌──────────┐ ┌──────────┐   │
│  │ Semantic │ │ Keyword  │ │  Graph   │   │
│  │ Search   │ │ Search   │ │ Search   │   │
│  │(pgvector)│ │(tsvector)│ │(wikilinks│   │
│  └────┬─────┘ └────┬─────┘ └────┬─────┘   │
│       └────────────┬────────────┘          │
│                    │                       │
│            ┌───────▼────────┐             │
│            │ RRF Merge      │             │
│            └───────┬────────┘             │
│                    │                       │
│  ┌─────────────────▼────────────────────┐ │
│  │ Markdown Vault (source of truth)     │ │
│  │ ~/Palimpsest/vault/*.md             │ │
│  └─────────────────────────────────────┘ │
└─────────────────────────────────────────────┘

Quick Start

# Clone the platform
git clone https://github.com/M4F-S/palimpsest
cd palimpsest

# Install (SQLite works out of the box)
pip install -e ".[dev]"

# Or with PostgreSQL + pgvector for production:
docker run -d --name palimpsest-pg -p 15432:5432 \
  -e POSTGRES_USER=palimpsest \
  -e POSTGRES_PASSWORD=palimpsest_secret \
  -e POSTGRES_DB=palimpsest \
  ankane/pgvector:latest

from palimpsest import UnifiedMemorySystem

memory = UnifiedMemorySystem()

# Save a memory
memory.remember(
    title="API Rate Limit Decision",
    content="100 req/min with burst to 200. Alert if p95 > 200ms.",
    tags=["api", "decision"],
    salience=0.9
)

# Search by meaning
results = memory.recall("rate limiting policy", mode="hybrid", top_k=5)

# Schedule a reminder
memory.remind_me("Review API metrics", "2026-07-07T09:00:00", recurring="weekly")

# Run nightly maintenance
memory.consolidate()

Kimi Skill

For the Kimi AI skill (minimal installable version):

👉 github.com/M4F-S/kimi-palimpsest-skill

The skill repo contains only the essential files for Kimi integration: SKILL.md, palimpsest/ package, and tests.

Documentation

Environment Variables

License

Apache 2.0