Perseus Vault · persistent memory · v2.20.2

Memory your agents keep, encrypted and yours.

A single Rust binary that gives agents durable memory across sessions. One file: no Docker, no Postgres, no cloud. So they stop re-deriving what they already learned, and stop repeating past mistakes.

55+ MCP tools 73.8% LongMemEval AES-256-GCM single Rust binary
$curl -sSf …/install.sh | sh && perseus-vault serve
Why it matters

An agent that forgets repeats its mistakes.

Without memory, every session relearns the same decisions, conventions, and dead ends, burning tokens and reintroducing errors you already fixed.

Vault gives agents durable recall with confidence decay, so what mattered stays and what didn't fades, and answers get better over time.

recall quality · LongMemEval QA (official harness)
Perseus Vault73.8%
Zep63.8%
Mem049.0%
longmemeval_s (500) · gpt-4o answerer + official judge · published competitor numbers
Built for agent memory

More than a vector store.

Hybrid recall

BM25 + dense vectors fused with reciprocal rank fusion. Offline embeddings (all-MiniLM-L6-v2) are compiled into the binary, so semantic search runs with zero network.

Bi-temporal history

Ask what a fact was, and when it was believed vs. actually true: as_of, valid_at, and full 2-axis queries.

Decay & lifecycle

Ebbinghaus decay fades unused memories; layer promotion moves what's accessed into core. Prune, archive, purge: you stay in control.

Entity graph & GraphRAG

Typed links, traversal, community detection, and global search across clusters. Holistic answers, not just nearest neighbors.

Encryption & audit

AES-256-GCM at rest (opt-in) with the search index in plaintext, plus an immutable SHA-256-chained journal for chain of custody.

RAG & state

Grounded Q&A over stored memories (mimir_ask), key-value state with TTL, and connectors for GitHub and files.

How it compares

MCP-native, local-first, encrypted.

Perseus Vault
Mem0
Zep
Deployment
Single binary
Cloud + self-host
Docker/Postgres
MCP-native tools
55+
5 (not native)
0
Offline / local
Fully local
Cloud-dependent
Docker needed
Encryption at rest
AES-256-GCM
Bi-temporal history
Yes

Competitor capabilities and tool counts per Perseus Vault's published comparison matrix; verify against each vendor's current docs.

Drops into your stack

Framework adapters, or any MCP host.

Ready-made adapters make Vault the default memory backend, and your agent's memory doubles as a Markdown knowledge base in Obsidian, Logseq, or Notion.

LangGraph CrewAI AutoGen Haystack LangChain Pydantic AI Google ADK any MCP client
Pairs with

Perseus · live context engine

Vault remembers the past; Perseus resolves the present. Together they hand your agent exactly the context a task needs, and cut the token bill.

Explore the context engine →