From the free book Delta: Closing the Specification Gap (Dhuri, 2026). The PDF is the canonical edition — figures, tables, and code formatting are simplified online.
Package
Filesystem
@modelcontextprotocol/ server-filesystem
read_file, list_directory
Scope to src/ only. Never root.
GitHub
@modelcontextprotocol/ server-github
get_file, search_code, create_pr
Fine-grained PAT minimum scopes.
PostgreSQL
@modelcontextprotocol/ server-postgres
query (read-only) ai_reader role. No PHI/PCI tables.
Pin version. Security review.