blackletter: contract review that splits deterministic rules from model judgment

blackletter reviews contracts in two layers: seven deterministic checks for governing law, liability caps, payment terms, auto-renewal notice, confidentiality duration, blank fields, and assignment clauses, plus three model-adjudicated checks for one-sided clauses, indefinite obligations, and clause contradictions. Findings are anchored to PDF pages with highlighted source text and stated reasoning. The stack is Next.js 16 and React 19 over FastAPI and Python 3.12, using PyMuPDF for text geometry, with 65 test cases and provider-agnostic model calls. If model calls fail it degrades to rules-only operation. MIT licensed, written by a former practicing attorney.