CLI Agent Spec

CLI Agent Spec is a behavioral contract for command-line tools invoked by AI agents rather than humans. It documents 74 failure modes an agent hits when calling a CLI built for a terminal — pagers that wait for a keypress, exit 1 that could mean nothing happened or half happened, silent serializer crashes — and answers them with 158 requirements in three implementation tiers, plus five JSON Schema type definitions. The three load-bearing contracts are a reserved 0–13 exit-code table where every code declares retryable and side_effects, a {ok, data, error, warnings, meta} response envelope, and a tool manifest --output json call that replaces iterative --help discovery. MIT, v1.6, one maintainer.