Your CLI's next user is not a human (akeemjenkins.com)

Recent advancements in command-line interface (CLI) design reveal a paradigm shift where AI agents, rather than humans, are the primary users. Traditionally, CLIs were built with the assumption that a person would interpret help messages and errors, but now AI models struggle to navigate these human-centric interfaces that rely on natural language. A new approach emphasizes a "contract" between the CLI and the AI agent, which includes features like JSON schema commands, standardized error envelopes, and separation of output streams for data and human communication. This design shift is significant for the AI/ML community because it allows agents to interact with CLI tools more efficiently and safely. By providing clear schemas in JSON, agents can automatically understand command structures without guessing, while standardized exit codes enable deterministic error handling. Advanced implementations of this contract have already been successfully deployed in tools like higgs for Proton Mail and ouracli for Oura Ring, showcasing that an agent-first design greatly enhances both the operational efficiency and safety of AI-driven workflows, as it reduces ambiguity and the likelihood of destructive actions caused by misunderstood commands.