# Modernize

For getting old prs up to date.

- Repository: https://github.com/t3dotgg/tstack (2584 stars)
- Category: Git and review
- License: MIT
- Last updated: 2026-10-28
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add t3dotgg/tstack --skill modernize -g -a claude-code -y`
Codex: `npx skills add t3dotgg/tstack --skill modernize -g -a codex -y`
Cursor: `npx skills add t3dotgg/tstack --skill modernize -g -a cursor -y`
Gemini CLI: `npx skills add t3dotgg/tstack --skill modernize -g -a gemini-cli -y`

## Description

For getting old prs up to date. Use when asked to rebase a pr or "modernize".

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Modernize

Modernize the idea, not just the branch. A clean rebase does not prove that the
PR still belongs in the product.

## Guardrails

- Always check to make sure you have pulled latest origin for your branch, main
  branch, and any other branch related to your work before starting.
- Treat existing worktree changes as user-owned. Use a disposable worktree when
  the active worktree is dirty or is being used for other work.
- Modernizing authorizes rebasing and updating the PR branch. It does not
  authorize merging, closing, changing the base branch, or expanding scope.
- Never use an unqualified force push. Update a rebased branch with
  `--force-with-lease` against the head SHA observed before the rebase.
- Do not post a PR comment unless the user asked for one. Use the
  `leaving-pr-comments` skill for every comment posted on the user's behalf.

## Establish the PR's intent

Resolve the PR and record its URL, state, base, head repository and branch,
current head SHA, author, checks, and review state. Read the title, body, linked
issues, commits, review threads, and complete diff. State the smallest coherent
goal the PR was trying to accomplish before judging its implementation.

Fetch the latest remote base and PR head. Use the PR's actual base branch,
usually `main`, rather than assuming the local branch is current. Record the
merge base so the original PR and subsequent base-branch changes can be
compared separately.

## Check what changed around it

Inspect commits and diffs added to the base branch since the PR diverged. Search
merged and open PRs when titles, code paths, or behavior suggest a replacement
or competing implementation.

Look beyond overlapping lines:

The rest: https://github.com/t3dotgg/tstack/blob/HEAD/skills/modernize/SKILL.md