Octobrain
Persistent memory for AI assistants — store insights, decisions, and knowledge that survives across conversations.

MCP Registry: mcp-name: io.github.Muvon/octobrain
Table of Contents
Octobrain gives your AI assistant a long-term memory. Store code insights, architecture decisions, bug fixes, and knowledge — then retrieve them with semantic search in future sessions. Works as a CLI tool or as an MCP server for integration with Claude Desktop and other AI tools.
Why Octobrain?
AI assistants start every conversation with zero context. You explain your project, your preferences, your decisions — every single time. Octobrain breaks that cycle:
- Persistent memory — Insights survive across sessions, not just within them
- Semantic search — Find memories by meaning, not exact keywords
- Auto-linking — Related memories connect automatically (Zettelkasten-style)
- Knowledge indexing — Ingest docs, articles, and files for retrieval
- MCP integration — Works with Claude Desktop and other MCP-compatible tools
Quick Start
# Install from crates.io
cargo install octobrain
# Store your first memory
octobrain memory memorize --title "API Design Pattern" \
--content "Use REST for CRUD, GraphQL for complex queries" \
--memory-type architecture --tags "api,design"
# Search memories
octobrain memory remember "how should I design APIs"
# Start MCP server for Claude Desktop integration
octobrain mcp
Installation
From crates.io (Recommended)
From Source
# Clone and build
git clone https://github.com/muvon/octobrain.git
cd octobrain
cargo build --release
# Binary location
./target/release/octobrain --help
Docker
docker pull ghcr.io/muvon/octobrain:latest
Homebrew (macOS/Linux)
brew install muvon/tap/octobrain
Feature Flags
Octobrain supports multiple embedding providers:
| Flag | Description | API Key Required |
|---|
fastembed | Local embeddings via FastEmbed | No |
huggingface | Local embeddings via HuggingFace | No |
| (default) | Both fastembed + huggingface | No |
| (no features) | API-based: Voyage, OpenAI, Google, Jina | Yes |
# Build with local embeddings (default, no API keys needed)
cargo build --release
# Build with API-based embeddings only
cargo build --no-default-features --release
For API-based embeddings, set the appropriate environment variable:
VOYAGE_API_KEY for Voyage AI
OPENAI_API_KEY for OpenAI
GOOGLE_API_KEY for Google
JINA_API_KEY for Jina
Usage
Memory Management
Store and retrieve insights, decisions, and context:
All memory subcommands accept global flags:
--scope <string> — Override project scope (default: auto-detected from Git remote)
--role <string> — Filter by role (e.g. "developer", "reviewer")
# Store a memory
octobrain memory memorize --title "API Design" \
--content "Use REST for CRUD, GraphQL for complex queries" \
--memory-type architecture --tags "api,design"
# Search memories (semantic search)
octobrain memory remember "api design patterns"
# Multi-query search for broader coverage
octobrain memory remember "authentication" "security" "jwt"
# Get a memory by ID
octobrain memory get <id>
# Get recent memories
octobrain memory recent --limit 20
# Filter by type
octobrain memory by-type architecture --limit 10
# Filter by tags
octobrain memory by-tags "api,security"
# Find memories related to files
octobrain memory for-files "src/main.rs,src/lib.rs"
# Update a memory
octobrain memory update <id> --title "New Title" --add-tags "new-tag"
# Delete a memory
octobrain memory forget --memory-id <id>
# Get memories relevant to the current Git commit
octobrain memory current-commit
# Show memory statistics
octobrain memory stats
# Clean up old/low-importance memories
octobrain memory cleanup
# Compact tables and refresh indices (run when searches slow down)
octobrain memory maintenance
# ⚠️ Delete ALL memory data
octobrain memory clear-all --yes
Memory Consolidation
Close a goal and fold all its contributing memories into a consolidated summary:
# Consolidate a goal (Achieves-link sources → Consolidated state, importance dampened)
octobrain memory consolidate <goal-id> --summary "Final summary"
# Sleep consolidation: auto-cluster recent similar memories
octobrain memory sleep-consolidate --threshold 0.85 --min-size 3
Memory Relationships
Connect related memories for context-rich retrieval:
# Create a relationship between memories
octobrain memory relate <source-id> <target-id> \
--relationship-type "depends_on" \
--description "Source requires target to function"
# View relationships for a memory
octobrain memory relationships <memory-id>
# Find related memories through relationships
octobrain memory related <memory-id>
# Auto-link similar memories (Zettelkasten-style)
octobrain memory auto-link <memory-id>
# Explore memory graph
octobrain memory graph <memory-id> --depth 2
Knowledge Base
Index and search web content, docs, and files:
# Index a URL
octobrain knowledge index https://docs.rs/tokio/latest/tokio/
# Index a local file (.txt, .md, .pdf, .docx, .html)
octobrain knowledge index ./docs/architecture.md
# Search knowledge base
octobrain knowledge search "how to handle async tasks"
# Search within a specific source (auto-indexes if outdated)
octobrain knowledge search "spawn blocking" --source https://docs.rs/tokio/
# Read full content of a URL or local file
octobrain knowledge read https://docs.rs/tokio/latest/tokio/
# Search indexed content by regex pattern
octobrain knowledge match "spawn_blocking|block_in_place"
# Store raw text content
octobrain knowledge store "meeting-notes" --content "Discussion points..."
# List indexed sources
octobrain knowledge list --limit 20
# Show statistics
octobrain knowledge stats
# Delete a source
octobrain knowledge delete https://example.com/docs
# Delete stored content by key
octobrain knowledge delete-stored "meeting-notes"
Knowledge Boxes
Import and sync git-backed knowledge bundles scoped to your projects:
# Import a remote git repo as a knowledge box
octobrain box import https://github.com/org/docs-repo.git
# Import at global scope (visible in every project)
octobrain box import https://github.com/org/docs-repo.git --global
# Pull and re-index all subscribed boxes + local .box/ directories
octobrain box sync
# List subscribed boxes
octobrain box list
# Remove a box
octobrain box remove github.com/org/docs-repo
MCP Server
Run as an MCP server for integration with Claude Desktop and other AI tools:
# Start with stdio transport (for Claude Desktop)
octobrain mcp
# Start with HTTP transport (for web-based tools)
octobrain mcp --bind 0.0.0.0:12345
Available MCP Tools:
| Tool | Description |
|---|
memorize | Store memories with metadata; optional related_to for inline relationships |
remember | Semantic search with filters; returns 1-hop graph neighbors |
forget | Delete memories (requires confirmation) |
knowledge | Unified tool: search, store, delete, read, match via command field |
| See MCP Integration for Claude Desktop setup. | |
Features
- Semantic Search — Find memories by meaning using vector embeddings, not exact keyword matches
- Hybrid Search — Combines BM25 full-text search with vector similarity for better results
- Reranking Support — Pluggable cross-encoder reranking stage (provider-dependent)
- Auto-Linking — Automatically connects semantically similar memories (Zettelkasten-style)
- Temporal Decay — Ebbinghaus forgetting curve for importance management
- Knowledge Indexing — Ingest URLs, PDFs, docs for retrieval
- Project Scoping — Isolate memories per Git project or share across projects
- Role Filtering — Tag memories by role (developer, reviewer, etc.)
- Query Expansion (HyDE-lite) — Pseudo-relevance feedback for +10-30% recall on long-tail queries
- MCP Protocol — Full MCP 2026-07-28 compliance for AI tool integration
Benchmarks
Retrieval quality of octobrain's knowledge system on standard BEIR datasets — nDCG@10, fully local, no LLM judge, using the harness's default embedder bge-small-en-v1.5 (384-dim, 33M params). Each corpus passage is indexed through octobrain's real retrieval path and scored against the official qrels (metrics reproduce pytrec_eval).
| Dataset | octobrain vector | octobrain hybrid | BM25¹ | bge-small-en-v1.5² |
|---|
| SciFact (5.2K docs, 300 q) | 0.722 | 0.742 | 0.665 | 0.713 |
| NFCorpus (3.6K docs, 323 q) | 0.341 | 0.363 | 0.325 | 0.343 |