# Core Concepts

URL: /milo-cli/docs/about/concepts/
Section: concepts
Tags: about, concepts

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Milo has two related building blocks: CLI turns typed functions into commands, schemas, MCP tools, and llms.txt. App runs a reducer-driven terminal interface with templates and input. The shared concepts are: Concept Role Command handler Typed Python function exposed to humans and agents Schema JSON Schema derived from annotations and docstrings Context Injected runtime object for output, global options, and app bridges State Serializable model for interactive apps Reducer Pure function that turns actions into new state Saga / Cmd Explicit side-effect boundary Template Kida view rendered from state Return Values How command return values become CLI output and MCP content. App Lifecycle How a Milo terminal app starts, dispatches actions, renders, and exits. Settings Configuration Configuration system with TOML/YAML/JSON loading, deep merge, profiles, and origin tracking.

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Metadata:
- Author: lbliii
- Word Count: 127
- Reading Time: 1 minutes