secondbrain-ai 0.3.2

Local-first personal memory daemon for macOS — captures, indexes, and exposes your screen-time history to MCP-aware AI assistants.

SecondBrain

Your personal AI memory. On your device. On your terms.

An open-source, local-first personal memory daemon. Captures, embeddings, knowledge graph, and audit log never leave your device.

Quick start · How it works · Why · ⭐ Star us on GitHub

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Why this exists

Modern knowledge work generates more context than any human can hold — meetings, threads, docs, browser tabs, code windows. The tools that promise to help typically lock your memory inside a vendor or stream your screen to someone else's GPU.

SecondBrain is a personal memory daemon that runs entirely on your Mac. It captures your screen, indexes it across four storage layers, and exposes that memory to any MCP-aware assistant — Claude Desktop, Cursor, Codex — through seven first-class tools. The default LLM is local Ollama; if you opt into a hosted provider, only the prompt text leaves your machine, and only because you said so.

Quick start

macOS 14+ (Apple Silicon). Windows/Linux paths raise NotImplementedError today.

git clone https://github.com/openintelligence-labs/secondbrain && cd secondbrain
python3 -m venv .venv && .venv/bin/pip install -e '.[dev,ml]'
.venv/bin/secondbrain run --fps 1                 # start the capture daemon

The [ml] extra installs the local text embedder (sentence-transformers + PyTorch). Skip it if you plan to use Ollama-served embeddings or the --stub-embedder flag — local embeddings pull ~2 GB of model weights on first use. For visual recall via ColQwen2.5 add [visual]; for BYO hosted LLMs add [byo-llm].

For the full desktop app (Tauri shell + Swift sidecars), build the two extra components after the Python install:

( cd swift/SecondBrainCapture && swift build -c release )
( cd app && npm install && npm run build && cd src-tauri && cargo build --release )
.venv/bin/secondbrain ui                          # launches the desktop window

Want to drive it without granting macOS Screen Recording first? Run ./demo.sh for a seeded fixture workday.

Features

	What it does
Continuous capture	ScreenCaptureKit sidecar at 1 fps, AX-tree-first dedup cascade (deny-list → AX-hash → dirty-rect → dHash → pHash → SSIM), <1ms median per gate.
Hybrid retrieval	Tantivy BM25 ⊕ LanceDB cosine → RRF k=60 → mxbai-rerank. p95 of 35 ms over 500 captures.
Visual recall	ColQwen2.5 late-interaction embeddings let you search for what a screen looked like, not just what it said.
Bi-temporal knowledge graph	Kùzu KG tracks valid-time and transaction-time for every entity. "What did I know about X last Tuesday?" is a first-class query.
MCP-native	A FastMCP server exposes 7 tools — memory.search, memory.who, memory.digest, memory.forget, and more — over stdio or Streamable HTTP.
BYO-LLM	Default is local Ollama. Switch to OpenAI, Anthropic, Gemini, Groq, or Mistral with three environment variables. Every LLM hot path has a deterministic heuristic fallback.
GDPR by construction	SQLCipher AES-256 at rest, age-encrypted files, biometric-gated session keys, signed audit log, and memory.forget as a first-class cascading delete.

How it works

  screen ──▶ cascade ──▶ extract ──▶ ┬─▶ SQLite  (OLTP, SQLCipher)
  (SCK)     (dedup 6   (entities,    ├─▶ LanceDB (dense vectors)
            stages)    importance)   ├─▶ tantivy (BM25)
                                     └─▶ Kùzu    (bi-temporal KG)
                                           │
                               ┌───────────┴────────────┐
                               ▼                        ▼
                        hybrid retrieval         Tauri desktop
                        (RRF k=60 + rerank)      + MCP server (7 tools)

Everything above the retrieval line stays on disk, encrypted. The MCP server and desktop app sit on top of the same retrieval layer, so a query from Claude Desktop and a click in the timeline window run the identical pipeline.

CLI surface

Command	Purpose
secondbrain run	Start the capture daemon. --fps, --ocr-fallback, --llm, --visual flags.
secondbrain run-synthetic	Same pipeline, synthetic frames — no display or TCC required.
secondbrain index	Bulk re-index OLTP → KG / Lance / tantivy.
secondbrain search "<query>"	Hybrid search with optional --rerank.
secondbrain who "<name>"	Person card across every source that mentions them.
secondbrain digest --period day	Daily/weekly/monthly reflection. Add --llm for LLM synthesis.
secondbrain forget --capture-id <id> --reason <r>	GDPR Art. 17 cascading delete.
secondbrain ui	Launch the Tauri desktop app + HTTP gateway.
secondbrain mcp	FastMCP stdio server for Claude Desktop / Cursor / Codex.
secondbrain mcp-doctor	Diagnostic + paste-ready MCP client config.
secondbrain preflight	Verify TCC permissions, sidecars, and dependencies.
secondbrain install-agent / uninstall-agent / agent-status	macOS launchd integration.
secondbrain backup <path> / restore <path>	Encrypted snapshot + restore.
secondbrain status	Capture and storage metrics.

Configuration

SecondBrain is configured by environment variables — no config file required for the local-only default. To point it at a hosted LLM, install the matching extra and export three vars:

# 1. Install the SDK for your chosen provider.
pip install -e '.[openai]'         # or [anthropic] / [gemini] / [groq] / [mistral]
                                    # or [byo-llm] for all five at once

# 2. Tell SecondBrain to use it.
export SECONDBRAIN_LLM_PROVIDER=openai         # ollama (default) | openai | anthropic
                                                # | gemini | groq | mistral
export SECONDBRAIN_LLM_MODEL=gpt-4o-mini       # any model the provider serves
export SECONDBRAIN_LLM_API_KEY=sk-...          # not needed for local Ollama
# export SECONDBRAIN_LLM_BASE_URL=...          # only for self-hosted endpoints

# 3. Verify.
secondbrain mcp-doctor                          # prints loaded providers + warnings

Captures, embeddings, KG nodes, and the audit log never leave your device. With a hosted LLM, only the prompted text egresses — and only on the calls you opted into.

Contributing

Contributions are welcome. Before opening a PR:

1. Browse src/secondbrain/ — modules are organised by pipeline stage (capture/, memory/, store/, search/, api/).
2. Run the deterministic suite: pytest tests/ --ignore=tests/test_macos_sck.py --ignore=tests/test_ocr.py (no network, no TCC required).
3. Project conventions: Pydantic models across module boundaries, heuristic fallback for every LLM hot path, capture IDs as hex UUIDs.

Questions, ideas, and bug reports go in GitHub Discussions and Issues.

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License

MIT © Open Intelligence Labs.