Vouch is a community trust management system that lets open-source projects gatekeep contributions behind an explicit vouching mechanism. It maintains a VOUCHED.td file (a flat text format called Trustdown) listing trusted and denounced users. The system provides a Nushell-based CLI for local management, and eight composite GitHub Actions for full GitHub integration: checking issues/PRs on open/reopen, managing vouches via issue or discussion comments, syncing CODEOWNERS, and installing the CLI. The entire implementation is in Nushell script, making it dependency-light (only requires `nu` and `gh`) while achieving surprising sophistication in API handling, retry logic, and file parsing. Architecturally, Vouch is modular: `vouch/file.nu` handles the custom TD file format with full comment/whitespace preservation; `vouch/lib.nu` provides pure-data operations (add, remove, check, denounce) that operate on parsed tables; `vouch/github.nu` wraps the GitHub REST and GraphQL APIs with exponential-backoff retry, collaborator permission checking, and automated commit/push workflows; and `vouch/template.nu` provides a simple template engine for custom response messages. The GitHub Actions in `action/` are composite actions that invoke these Nushell modules directly. The quality of the codebase is notably high for a Nushell project: it follows a disciplined module structure, has comprehensive tests (both fast unit tests and slow integration tests against the live mitchellh/vouch repository), uses typed flags and structured error handling, and implements patterns like retry with rebase for concurrent edits. The TD file parser (`from td`/`to td`) is a particularly well-crafted component that could be extracted as a standalone Nushell module for any project needing a simple, human-readable trust list format. The comment parsing regex patterns are robust against injection and multiline attacks. Overall, Vouch is a well-engineered, self-dogfooded tool that solves a real open-source moderation problem with minimal external dependencies.