Burn Your Flags: Interactive CLIs for Agents — Mark Lummus & Navinkumar Patil, PayPal
This workshop addresses the challenge of making interactive Command Line Interfaces (CLIs) usable by AI agents. Traditional methods, like adding command flags, fail when the workflow is contextual, sequential, or depends on live API responses. The presentation introduces advanced techniques—including `tmux` sessions, IPC side channels, and context injection—to provide agents with the necessary structured context and state management, moving beyond simple screen scraping to enable robust, multi-step agentic workflows.
Key takeaways
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Interactive CLI Limitations for Agents
7:15
Agents struggle with interactive CLIs because they may fail silently (e.g., seeing a redraw loop instead of a question) [0:00, 0:00]. Flags are insufficient when choices are contextual or depend on real-time API responses, unlike simple, independent command flows [4:35].
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Advanced Agentic CLI Techniques
43:11
Three key approaches were presented to improve agent interaction with CLIs: 1) Using `tmux` sessions for key sending and capturing terminal state [25:51]. 2) Implementing IPC side channels to expose structured JSON output instead of relying on screen scraping [28:28]. 3) Context injection, which explicitly provides constraints and options to the agent, mimicking human guidance [31:00].
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The Importance of Determinism
For a CLI to be reliably used by an LLM, it must be deterministic. The CLI should act as a 'small sharp instrument' that provides the same response every time a command is given, leaving the non-deterministic role to the LLM [42:00].