uv-tool-updater

uv-tool-updater coordinates safe updates for Python CLI, desktop, and tray applications installed by uv tool install. It does not modify an environment itself: installation is delegated to uv tool upgrade, after the host process exits.

Status: early MVP (0.1.4). The public API and result schema may evolve before 1.0.

Install

uv add uv-tool-updater

The host must provide a private state directory. This avoids imposing a platform-directory dependency and lets GUI applications use their existing settings location.

Interactive update smoke test

Install this project as a uv tool, then run the bundled test command:

uv tool install uv-tool-updater
show-version

show-version prints the installed version, checks PyPI, and asks before updating when a newer release exists. Only y or Y starts the normal external-helper update flow. The command exits, uv tool upgrade uv-tool-updater runs after that process has ended, and show-version is restarted to report the result.

For an isolated test state directory, set UV_TOOL_UPDATER_STATE_DIR before running the command.

Before the project is published to PyPI, simulate release metadata with:

show-version --latest-version 0.1.4

This option changes only the metadata used by the version check. The update itself still runs uv tool upgrade uv-tool-updater and therefore uses the source saved by uv. For a local-path installation, change the project version and source first, while leaving the installed tool on the older version, then run the command with that newer version number.

On Windows, a console command restarted by the hidden helper may not receive an interactive terminal. In that case it exits without consuming the result; run show-version once more in the existing terminal to display the completed update result.

Minimal integration

import os
from pathlib import Path

from uv_tool_updater import UpdateStatus, Updater

updater = Updater(
    package_name="fshot",
    command_name="fshot",
    state_dir=Path.home() / ".local" / "state" / "fshot" / "updates",
)

# Run this synchronous network operation on a worker thread in GUI applications.
check = updater.check()
if check.status is UpdateStatus.UPDATE_AVAILABLE and check.release is not None:
    # The host must first save data or receive explicit permission to discard it.
    session = updater.prepare_update(check.release, restart_args=[])
    session.start_helper(host_pid=os.getpid())
    # Only now ask the framework to quit normally.

On restart, use updater.consume_latest_result() (or consume a path returned by pending_results()). Consumption re-reads the actual installed distribution version; a zero uv exit code alone is never presented as proof that the version changed.

Guarantees and limits

• Python 3.10–3.14; Windows, macOS, and Linux.
• Public PyPI metadata by default; inject StaticProvider or a custom ReleaseProvider for tests/private indexes.
• Stable releases by default; prereleases are opt-in.
• Automatic installation is refused outside a detected uv tool environment and for editable installs.
• The helper waits up to 10 minutes by default and never terminates the host.
• Failed upgrades restart the original command by default and preserve a local log.
• No telemetry and no GUI-framework dependency.

Documentation

• Architecture and lifecycle
• Host integration guide
• External helper protocol
• Security model
• Testing
• Troubleshooting
• Release procedure
• Changelog