difftree-action-setup

name	difftree-action-setup
description	Install the difftree CLI and/or add difftree PR diff-tree comments to a repository. Use when the user says "install difftree", "set up difftree", "add difftree to my repo", "add PR diff-tree comments", "set up difftree-action", or wants difftree running locally or in CI. Installs the difftree CLI (prebuilt binary, `cargo install difftree`, or from source) and scaffolds a `.github/workflows/pr-diff-tree.yml` that runs smorinlabs/difftree-action from this repo's canonical examples/pr-diff-tree.yml, then commits or opens a PR. This is the difftree-action repo's own setup skill; the difftree CLI repo ships a lightweight pointer to it.
allowed-tools	Bash, Read, Write, Edit

difftree-action-setup

Install the difftree CLI and/or add self-updating PR diff-tree comments to a repository via smorinlabs/difftree-action.

When this fires

Triggers: "install difftree", "set up difftree", "add difftree to my repo", "add PR diff-tree comments", "set up difftree-action". First confirm which half the user wants — CLI install, repo/CI wiring, or both — then run only those steps.

1. Install the difftree CLI (if requested)

Use the first method that fits the environment, then verify with difftree --version:

1. Prebuilt binary (no Rust toolchain needed). difftree ships a binary per release named difftree-<tag>-<target>.<ext> with a matching .sha256. Targets: x86_64-unknown-linux-gnu, aarch64-unknown-linux-gnu, x86_64-apple-darwin, aarch64-apple-darwin, x86_64-pc-windows-msvc (.tar.gz, except Windows .zip). Resolve the target from uname -sm, get the latest tag with gh release view --repo smorinlabs/difftree --json tagName -q .tagName, download that asset, verify the checksum, extract, and put difftree on PATH.
2. From crates.io (needs Rust). cargo install difftree.
3. From source. git clone https://github.com/smorinlabs/difftree then cargo install --path difftree.

2. Wire difftree-action into a repo (if requested)

1. Identify the target repo — the user's repo, not this one — and cd there.
2. Write the canonical workflow: read examples/pr-diff-tree.yml from this (difftree-action) repo — relative to this skill it is ../../examples/pr-diff-tree.yml; if unreachable, fall back to https://raw.githubusercontent.com/smorinlabs/difftree-action/v0/examples/pr-diff-tree.yml — and save it to the target's .github/workflows/pr-diff-tree.yml.
3. Keep the three load-bearing bits the template carries; removing any one breaks the action: fetch-depth: 0 on actions/checkout, permissions: pull-requests: write, and the concurrency group.
4. Apply only the inputs the user asked for (level, dirs-only, difftree-version, comment, advertise) in the with: block; leave the rest at their defaults. action.yml is the authoritative input reference.

3. Commit / open a PR

In the target repo, branch, commit the workflow with a conventional message (e.g. ci: add difftree PR diff-tree comments), and open a PR — never push to the default branch directly. Report the PR URL.

See also

• examples/pr-diff-tree.yml — the canonical workflow this skill scaffolds; the single source of truth (do not embed a second copy here).
• README.md, action.yml — full input/output reference for difftree-action.
• difftree CLI: https://github.com/smorinlabs/difftree — its difftree-setup pointer skill routes here.