This repository is a local-first, source-cited knowledge base management system, delivered primarily as a Claude Code plugin and a standalone Python CLI tool. It manages Obsidian vaults with a strong emphasis on data integrity, provenance tracking, and deterministic operations. The architecture is a monolithic Python library (`claude_obsidian/`) with a formal transaction system for all vault mutations, a robust lint engine, and a retrieval pipeline (BM25 + optional semantic reranking). It features a sophisticated skill/agent framework for AI integration across multiple hosts (Claude, Cursor, Windsurf, etc.). While primarily an application, it incorporates significant data engineering and research data management (RDM) patterns. The provenance ledger system (`ledgers.py`) enforces strict schemas for sources and claims, including canonical URL handling, content-addressed identity, and evidence validation rules. The retrieval pipeline implements Anthropic's Contextual Retrieval pattern. This hybrid nature makes it a powerful tool for both knowledge management and structured research workflows. The codebase demonstrates exceptionally high craftsmanship in its transaction system, defensive I/O, and deterministic analysis tools. It is actively maintained with a comprehensive test suite and a formal release process. Its primary limitation is platform dependency on Linux/macOS for write operations (WSL required for Windows).