Show HN: Jeff – A read-only CLI for semantic code review using Jev

Jeff is a read-only command-line tool written in Go that performs semantic code review by running files against a rule set powered by Jev. Designed for use both interactively and in CI, it inspects code to surface architectural and semantic problems rather than syntax or style issues. Authentication to TypeSafe is supported via an API key or a credential stored in the OS keyring (jeff auth login/logout), and a TYPESAFE_BASE_URL can be set for testing against compatible endpoints.

Usage centers on jeff check PATH... with options for text or json output; text highlights failed checks and summarizes results, while json emits structured results suitable for automation. Exit codes are meaningful: 0 means all applicable checks passed, 1 indicates a conclusive violation was found, and 2 denotes usage, configuration, input, provider, internal, or inconclusive results. The repository documents about 20 GEN### rules that detect problems such as unclear responsibilities, misleading naming, hidden side effects, weak or missing error handling and validation, excessive complexity, inappropriate coupling, duplicated domain knowledge, poor boundary separation, and testability issues. Jev reference documentation is included in docs/references/jev for rule authors and integrators.