# second-brain

A personal knowledge system: video/article extraction pipeline + LLM-maintained wiki.

## Architecture

Three-layer system:

1. **Wiki** — long-term structured memory. Markdown files in an Obsidian vault, maintained by the wiki compiler.
2. **Context assembler** — builds the prompt bundle for each extraction. Phase 1 is thin: domain template + focus field + transcript.
3. **Extractor** — stateless single-shot LLM call per source. Pure function: bundle in, structured extraction out.

## Pipeline stages

```
pending → pulled → transcribed → analyzed → accepted → published
```

## Project layout

```
src/second_brain/
├── adapters/      # Pull adapters (youtube.py, article.py)
├── context/       # Context assembler
├── extractor/     # LLM extraction engine + Pydantic schema
├── compiler/      # Wiki compiler (reads vault, writes pages, git commits)
├── scheduler/     # Rate-limit smoother, token-aware spacing
└── web/           # FastAPI + Jinja2 + HTMX UI
```

## Setup

```bash
cp config/settings.toml.example config/settings.toml
# Edit settings.toml with your paths
uv run second-brain serve
```

## CLI commands

- `second-brain add <url>` — queue a source URL (video or article)
- `second-brain process` — run the pipeline on pending items
- `second-brain serve` — launch the web UI (default port 8000)
- `second-brain compile` — run the wiki compiler
- `second-brain schedule` — start the overnight scheduler

## Environment variables

- `ANTHROPIC_API_KEY` — required for extraction and wiki compilation

## Domains

- `development` — software, programming, systems
- `content` — content creation strategy, video production
- `business` — entrepreneurship, marketing, operations
- `homelab` — self-hosted infrastructure, networking, DevOps

## Key files

- `config/settings.toml` — vault path, DB path, scheduler window
- `prompts/<domain>.md` — per-domain extraction prompt templates
- `src/second_brain/extractor/schema.py` — canonical extraction output schema