# About

URL: /milo-cli/docs/about/
Section: about
Description: Philosophy, architecture, concepts, thread safety, and ecosystem.

---

> For a complete page index, fetch /milo-cli/llms.txt.

Background on Milo's philosophy, architecture, concepts, free-threading model,
and ecosystem.

Aspect
Milo's approach

State
Immutable dicts or frozen dataclasses — never mutated

Updates
Pure reducer functions — deterministic, testable

Views
Kida (https://lbliii.github.io/kida/) templates — declarative, hot-reloadable

Effects
Generator-based sagas — explicit, composable, thread-pool parallel

Concurrency
Python 3.14t free-threading — no GIL contention

Philosophy

The design constraints behind Milo's command and app model.

(/milo-cli/docs/about/philosophy/)

Architecture

How Milo's Elm Architecture maps to terminal applications.

(/milo-cli/docs/about/architecture/)

When to Use Milo

Choose Milo for typed CLIs, MCP tools, and reducer-driven terminal apps.

(/milo-cli/docs/about/when-to-use/)

Ecosystem

How Milo fits with Kida templates, Bengal docs, and agent-facing CLIs.

(/milo-cli/docs/about/ecosystem/)

Thread Safety

How Milo approaches free-threaded Python and shared mutable state.

(/milo-cli/docs/about/thread-safety/)

## In This Section

Core Concepts (/docs/about/concepts/)

The main ideas shared by Milo CLIs and interactive apps.

4 pages

Architecture (/milo-cli/docs/about/architecture/)

How Milo's Elm Architecture maps to terminal applications.

Ecosystem (/milo-cli/docs/about/ecosystem/)

How Milo fits with Kida templates, Bengal docs, and agent-facing CLIs.

Philosophy (/milo-cli/docs/about/philosophy/)

The design constraints behind Milo's command and app model.

Thread Safety (/milo-cli/docs/about/thread-safety/)

How Milo approaches free-threaded Python and shared mutable state.

When to Use Milo (/milo-cli/docs/about/when-to-use/)

Choose Milo for typed CLIs, MCP tools, and reducer-driven terminal apps.

Related Pages

Return Values (/milo-cli/docs/about/concepts/return-values/)

How command return values become CLI output and MCP content.

Related

App Lifecycle (/milo-cli/docs/about/concepts/app-lifecycle/)

How a Milo terminal app starts, dispatches actions, renders, and exits.

Related

Core Concepts (/milo-cli/docs/about/concepts/)

The main ideas shared by Milo CLIs and interactive apps.

Related

about (/milo-cli/tags/about/)