herdr is a terminal-based AI agent multiplexer allowing simultaneous calls to multiple large language models. It supports providers like OpenAI, Anthropic, and local Ollama models, displaying their responses side-by-side in the terminal. This tool is ideal for developers who frequently compare outputs from different AI models, saving the effort of manual copying and pasting. Installation is straightforward via Homebrew or Go, and configuration is managed through a YAML file. While herdr offers parallel execution, its "agent" capabilities are limited, functioning more as a CLI wrapper. The tool handles basic prompt templating but lacks advanced logic. Performance tests show negligible overhead and significant time savings compared to serial model calls. Users may encounter issues with environment variable expansion and timeouts for slow local models. Output formatting in JSON mode can also require manual filtering for null responses. Herdr distinguishes itself by natively supporting terminal-based multi-model output comparison, a feature not found in tools like OpenRouter or LangChain CLI. It is recommended for developers needing quick comparisons and bloggers showcasing model differences. However, it is not suitable for complex agent frameworks or production environments due to its early stage.