Copier CLI

Flow Tool: Copier CLI FLTL_COPIER
status: approved
tags: ubflow, installer
used_by: AGENT_INSTALLER
skills: FLSK_UBFLOW_INST_002, FLSK_UBFLOW_INST_003

Copier is the template rendering engine used for all installation and upgrade operations. It is invoked as copier copy / copier update and reads copier.yml for prompts and hooks. Minimum required version: 9.0.0.

Usage

The installer invokes Copier in four modes:

Mode

Purpose

copier copy

Initial installation — renders the template into the target directory.

copier update

Upgrade an existing installation to a newer package version.

--pretend

Dry run — shows the diff without writing any files. Used before every upgrade.

--overwrite

Allows overwriting existing files. Requires explicit per-file confirmation.

Constraints

  • Never pass --vcs-ref — versions are resolved from ubflow_package.json, not git tags.

  • The source path passed to Copier MUST be a directory. Never pass a zip path directly.

  • Copier MUST NOT be invoked while ID conflicts or prerequisite failures are open.