Loci

Your personal knowledge map. Loci transforms any document into a visual, explorable knowledge space with automatic flashcard generation and spaced repetition for long-term retention.

What is Loci?

Loci is a learning system that:

• Ingests anything: PDFs, markdown, text files, handwritten notes (photos), audio transcriptions, images
• Extracts knowledge: Automatically identifies concepts and their relationships
• Visualizes spatially: Displays your knowledge as an interactive honeycomb map where related concepts cluster together
• Strengthens memory: Generates flashcards and schedules reviews using spaced repetition (FSRS algorithm)

Features

Visual Knowledge Map

Navigate your knowledge like a map. Zoom from high-level categories down to individual concepts. Related ideas appear close together thanks to semantic clustering.

Universal File Ingestion

Drop in any file type:

• Documents (PDF, Markdown, TXT)
• Handwritten notes (photos processed via LLM vision)
• Images with text or diagrams
• Audio transcriptions

Automatic Flashcard Generation

Each concept generates smart flashcards using two formats:

• Cloze deletions (easy/medium): Fill-in-the-blank with context cues
• Q&A (hard): Direct questions for deeper active recall

Spaced Repetition (FSRS)

Reviews are scheduled at the optimal moment—just before you'd forget. The system tracks:

• Stability: How long until memory drops to 90%
• Difficulty: How hard the material is for you
• Retrievability: Current probability of recall

Semantic Search

Find any concept instantly. Search queries match semantically, not just by keywords.

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How It Works

1. Document Processing

Files are parsed and split into meaningful chunks using LangChain text splitters. Images and handwritten notes are processed through LLM vision capabilities.

2. Concept Extraction

An LLM analyzes each chunk to extract:

• A clear title
• A concise summary
• The core content

3. Embedding Generation

Each concept is converted to a high-dimensional vector (embedding) that captures its semantic meaning. Similar concepts have similar embeddings.

4. Dimensionality Reduction (UMAP)

Embeddings are projected from high-dimensional space to 2D coordinates using UMAP, preserving semantic relationships. This creates the spatial layout where similar concepts appear near each other.

5. Clustering (HDBSCAN)

Concepts are grouped into clusters using HDBSCAN, a density-based algorithm that finds natural groupings without requiring a predefined number of clusters.

6. Honeycomb Visualization

The 2D coordinates are rendered as an interactive honeycomb grid. Each hexagon represents a concept. Opacity reflects learning progress—mastered concepts fade while due reviews stand out.

7. Flashcard Generation

For each concept, the LLM generates flashcards:

• Cloze deletions provide context cues for easier learning
• Q&A format tests deeper recall for challenging material

8. Spaced Repetition (FSRS)

The FSRS algorithm schedules reviews based on your performance:

• Again: Reset, review soon
• Hard: Small interval increase
• Good: Normal interval increase
• Easy: Large interval increase, decrease difficulty

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Getting Started

Prerequisites

• Python 3.11+
• Node.js 18+ with pnpm
• Either:
  • OpenAI (recommended): gpt-4.1-mini + text-embedding-3-small
  • Ollama (local): ministral-3:8b + embeddinggemma

Quick Start

# Clone and enter the project
git clone <repo-url>
cd loci

# Run the start script
./start.sh

The script will guide you through setup and start both servers.

Manual Setup

Backend

cd backend

# Install dependencies with uv
uv sync

# Set your OpenAI API key
export OPENAI_API_KEY="sk-..."

# Or for local mode with Ollama:
# 1. Install Ollama: https://ollama.ai
# 2. Pull models: ollama pull ministral-3:8b && ollama pull embeddinggemma

# Start the server
uv run python main.py

Backend runs at http://localhost:4224

Frontend

cd frontend

# Install dependencies
pnpm install

# Start dev server
pnpm dev

Frontend runs at http://localhost:3000

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API Endpoints

Documents

Endpoint	Method	Description
/upload	POST	Upload and process a file
/concepts	GET	List all concepts
/concepts/{id}	GET	Get concept details
/search	GET	Semantic search

Reviews

Endpoint	Method	Description
/review/due	GET	Get flashcards due for review
/review/due/count	GET	Count of due cards
/review/submit	POST	Submit review with rating (1-4)
/review/grade	POST	Grade answer using LLM
/review/stats	GET	Review statistics

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Tech Stack

Backend: FastAPI, LangChain, SQLite + sqlite-vec, UMAP, HDBSCAN

Frontend: Nuxt 4, Vue 3, Honeycomb Grid, D3, Panzoom

AI Models:

• OpenAI: gpt-4.1-mini (VLM) + text-embedding-3-small (embeddings)
• Ollama: ministral-3:8b (VLM) + embeddinggemma (embeddings)

Algorithm: FSRS (Free Spaced Repetition Scheduler)

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License

MIT