# Milo 0.4.2

URL: /milo-cli/releases/0.4.2/
Section: releases
Description: Released Chirp adoption proof, the Waypoint showcase, and reproducible launch evidence.

---

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

Proof-and-showcase release demonstrating Milo in a released downstream CLI and
across a complete human, agent, and MCP Apps workflow.

## Highlights

- **Released Chirp adoption** — The exact-version downstream canary now pins
  `milo-cli==0.4.1` with `bengal-chirp==0.10.0`, the first Chirp release whose
  packaged eleven-command CLI runs on Milo. It verifies help, parsing, output
  channels, lazy imports, structured dispatch, and the reviewed `check`, `diff`,
  and `routes` MCP/llms.txt allowlist under Python 3.14 free-threading.
- **Waypoint vertical proof** — A dependency-free showcase carries validated
  intent checkpoints through isolated git snapshots, competing attempts,
  conflict-safe selection, undo, human timeline views, agent resources,
  streaming progress, and an interactive MCP Apps graph.
- **Reproducible launch evidence** — The comparison with Typer plus FastMCP now
  includes same-app fixtures and a machine-checked public claims ledger instead
  of relying on prose-only positioning.
- **Stronger project hygiene** — Contributor and security guidance, a documented
  test taxonomy, property-based schema and reducer checks, and both GIL-on and
  free-threaded CI lanes make the repository's quality claims inspectable.

## Added

- A mature-CLI adoption guide covering compatibility inventory, typed adapters,
  lazy command registration, help/output/exit preservation, agent-surface
  policy, phased cutover, and exact-release downstream canaries.
- A clean-checkout Waypoint replay that exercises hook-driven CLI checkpoints,
  real MCP inspection and selection, and both human TUI and MCP Apps views.
- Reusable CI documentation and repository governance for release-class proof.

## Compatibility Notes

Milo's runtime API, Python 3.14+ requirement, and sole runtime dependency range
`kida-templates>=0.11.0,<0.12.0` are unchanged. The new material is showcase,
documentation, CI, and downstream compatibility evidence built on the released
0.4.1 runtime contract.

Upgrade with:

```bash
pip install --upgrade "milo-cli==0.4.2"
```