Mimir

Self-hosted persistent memory for OpenClaw agents via Mimir MCP — 23 tools, hybrid search, AES-256 encryption, zero external dependencies

Mimir — Self-Hosted Persistent Agent Memory

Purpose

This skill connects your OpenClaw agent to Mimir, a self-hosted Rust binary that provides durable, encrypted persistent memory via stdio MCP. No cloud, no API keys, no Docker — just one binary serving 23 memory tools.

Mimir runs entirely on your machine. No data leaves your environment. No external service sees your agent's memories. Every stored memory is AES-256-GCM encrypted at rest.

What Mimir Does

Full persistent memory lifecycle

Your agent can remember facts, decisions, and context; recall them across sessions with keyword search; search semantically via dense embeddings; and forget stale memories. All memory operations are durable and survive OpenClaw restarts.

Hybrid search

Mimir combines BM25 keyword search (FTS5) with dense vector embeddings via Reciprocal Rank Fusion (RRF). Your agent gets the best of both worlds — exact keyword matches and semantic similarity in a single query.

Encryption at rest

All stored data is AES-256-GCM encrypted. Even if someone accesses the database file, they can't read your agent's memories without the encryption key.

Memory lifecycle management

Mimir applies Ebbinghaus decay to memories — rarely-used facts fade and eventually archive. Your agent's context stays sharp without manual cleanup. Run a mimir_cohere grooming pass to auto-link related memories, promote frequently-used ones, and archive decayed ones.

No external dependencies

Mimir is a single Rust binary (~8MB). No Docker, no PostgreSQL, no Redis, no cloud service. Drop it in, start it, connect via stdio MCP. It runs anywhere OpenClaw runs — Linux, macOS, Windows, even a Raspberry Pi.

Available Tools (23 total)

Core CRUD

• mimir_remember — Store a fact, decision, or observation with category, key, tags, and confidence
• mimir_recall — Keyword search across all stored memories with FTS5
• mimir_get_entity — Retrieve full details of a specific memory
• mimir_forget — Soft-delete a memory (recoverable)

Semantic search

• mimir_embed — Generate and store dense embeddings for vector search
• mimir_search_memories — Semantic search via dense embeddings (requires --llm-endpoint)
• mimir_ask — Ask a natural language question, get a grounded answer with cited sources

Memory lifecycle

• mimir_cohere — Autonomous grooming: promote hot memories, link related ones, archive stale
• mimir_decay — Recalculate Ebbinghaus decay scores across all memories
• mimir_prune — Bulk archive low-decay or old memories
• mimir_compact — Archive memories below a decay threshold

Knowledge graph

• mimir_link — Create relationships between memories
• mimir_unlink — Remove stale relationships
• mimir_traverse — Walk the relationship graph from any memory

Journal & timeline

• mimir_journal — Append structured decision/observation log entries
• mimir_timeline — Query the journal by time range and event type

Vault (import/export)

• mimir_vault_export — Export all memories to Obsidian-compatible .md files
• mimir_vault_import — Import .md vault files, idempotent (no duplicates)

State & proactive recall

• mimir_state_set / mimir_state_get / mimir_state_delete — Key-value state with optional TTL
• mimir_recall_when — Proactive just-in-time memory: surfaces relevant memories before tool calls
• mimir_conflicts — Detect contradictory or duplicate memories for review

Monitoring

• mimir_health — Health check
• mimir_stats — Entity counts by category, database size, date range
• mimir_context — Pre-formatted markdown context block for session injection
• mimir_workspace_list — List all knowledge domains in the database

Setup Instructions

Step 1 — Install Mimir

Choose one:

Download binary (fastest):

bash

# Linux x86_64
curl -L https://github.com/Perseus-Computing-LLC/mimir/releases/latest/download/mimir-linux-x86_64 -o mimir
chmod +x mimir
sudo mv mimir /usr/local/bin/

Build from source (requires Rust):

bash

git clone https://github.com/Perseus-Computing-LLC/mimir.git
cd mimir
cargo build --release
sudo cp target/release/mimir /usr/local/bin/

Python client (optional, for scripts):

bash

pip install mimir-client

Step 2 — Configure Mimir as an MCP server in OpenClaw

Add to your OpenClaw MCP servers config:

json

{
  "mcpServers": {
    "mimir": {
      "command": "mimir",
      "args": ["--db", "~/.openclaw/mimir/mimir.db"],
      "env": {
        "MIMIR_ENCRYPTION_KEY": "${MIMIR_ENCRYPTION_KEY}"
      }
    }
  }
}

For semantic search with embeddings, also set:

json

{
  "mcpServers": {
    "mimir": {
      "command": "mimir",
      "args": [
        "--db", "~/.openclaw/mimir/mimir.db",
        "--llm-endpoint", "http://localhost:11434"
      ],
      "env": {
        "MIMIR_ENCRYPTION_KEY": "${MIMIR_ENCRYPTION_KEY}"
      }
    }
  }
}

Step 3 — Generate an encryption key (optional but recommended)

bash

# Generate a 32-byte key
MIMIR_ENCRYPTION_KEY=$(openssl rand -hex 32)
echo "MIMIR_ENCRYPTION_KEY=$MIMIR_ENCRYPTION_KEY" >> ~/.openclaw/.env

Without an encryption key, Mimir stores data unencrypted (still local).

Step 4 — Initialize and verify

bash

# Create the database directory
mkdir -p ~/.openclaw/mimir

# Start Mimir once to initialize
mimir --db ~/.openclaw/mimir/mimir.db --health

# Verify it's running
mimir --db ~/.openclaw/mimir/mimir.db --stats

Then start a new OpenClaw session. Your agent now has access to all 23 Mimir memory tools.

Step 5 — Web dashboard (optional)

bash

# Start the web dashboard on port 8789
mimir --db ~/.openclaw/mimir/mimir.db --dashboard --port 8789
# Open http://localhost:8789

Data Handling & Privacy

Mimir is entirely self-hosted. No data leaves your machine.

• What gets stored: Only what your agent explicitly passes to mimir_remember or mimir_journal tool calls. No automatic capture, no silent monitoring.
• Where it's stored: A local SQLite database at the path you specify (--db). You control the file.
• Encryption: AES-256-GCM at rest when an encryption key is provided. Without a key, data is stored in plaintext SQLite (still local).
• Who can read it: Only processes with access to the database file and encryption key. No network access by default.
• Retention: Memories decay naturally via Ebbinghaus scoring. You control decay thresholds. Nothing is deleted without your agent's action.
• No telemetry: No analytics, no usage tracking, no phone-home. Mimir is a local binary.
• MIT licensed: Fully open source. You can audit the code, fork it, embed it.

Constraints

• No cloud sync: Mimir is local-only by design. Use mimir_vault_export and git for backup/sharing.
• Embeddings require Ollama or compatible endpoint: Semantic search needs --llm-endpoint pointing to an Ollama instance or compatible embedding API. Keyword search (FTS5) works without it.
• Single-writer: Mimir uses SQLite. One process at a time. Works perfectly for a single-agent OpenClaw setup.

Complementary Skills

Pair Mimir with these ClawHub skills for a complete memory stack:

• memory-audit-guardian — Weekly memory governance audit
• skill-from-memory — Extract reusable skills from stored memories
• knox-governance — Audit logging of all memory operations

CI / Automation

To run Mimir in CI or scheduled jobs:

bash

# Start Mimir in the background
mimir --db /tmp/mimir_ci.db &

# Run a coherence grooming pass nightly
mimir --db ~/.openclaw/mimir/mimir.db --cohere

# Export to vault for git backup
mimir --db ~/.openclaw/mimir/mimir.db --vault-export ~/mimir-vault/

Links

• GitHub: https://github.com/Perseus-Computing-LLC/mimir
• Website: https://perseus.observer/mimir
• Python client: https://pypi.org/project/mimir-client/
• Smithery: https://smithery.ai/server/mimir