Introduction
Mnemo is an MCP-native memory database for AI agents. It provides persistent, structured memory with semantic search, access control, hash-chain verification, and multi-agent collaboration primitives.
Key Features
- 21 MCP Tools: core memory ops (remember, recall, forget, forget_subject, share, consolidate), git-like state (checkpoint, branch, merge, replay), delegation & verification (delegate, verify, trajectory_audit), attention state, agent-controlled
mem_*, and plan memory — see the tools reference - Hybrid Retrieval: Vector similarity (USearch/pgvector) + BM25 full-text (Tantivy) + recency + graph signals fused via Reciprocal Rank Fusion
- Access Control: Owner-based permissions, ACL sharing, transitive delegation with time bounds
- Integrity Verification: SHA-256 hash chains over memory records with tamper detection
- Git-like State Management: Checkpoint, branch, merge, and replay agent memory states
- Cognitive Forgetting: Ebbinghaus decay curves, consolidation, archival strategies
- Memory Poisoning Detection: Anomaly scoring with automatic quarantine
- Multiple Backends: DuckDB (embedded) or PostgreSQL (distributed)
- REST API: Full HTTP API alongside MCP stdio transport
- SDKs: Python (with LangGraph, CrewAI, OpenAI Agents integrations), TypeScript, Go
Use Cases
- Agent Memory: Give LLM agents persistent memory across conversations
- Multi-Agent Collaboration: Share memories between agents with fine-grained permissions
- Audit Trails: Immutable event logs with hash-chain integrity verification
- Knowledge Management: Store, retrieve, and organize agent-generated knowledge
Architecture
Mnemo is built in Rust for performance and safety. The workspace contains:
| Crate | Purpose |
|---|---|
mnemo-core | Storage, indexing, query engine, models |
mnemo-mcp | MCP server (rmcp 3.0) |
mnemo-cli | Binary with CLI args |
mnemo-postgres | PostgreSQL storage backend |
mnemo-rest | Axum REST API |
python/ | PyO3 Python bindings |