jj

jj is a skill for Claude Code, Codex from megumish/jj-skill. It costs 78 tokens per session (1,163 once invoked), scanned A, original, Apache-2.0.

A guide for using Jujutsu, a version-control system that manages code changes and can work with Git repositories. It explains Jujutsu commands for status, history, changes, bookmarks, fetching, and pushing.

In plain words
What is it for?
It helps inspect changes, describe commits, create bookmarks instead of branches, fetch remote updates, rebase work, and push selected bookmarks.
Why use it?
It prevents developers from using Git commands in a repository managed through Jujutsu, where that could corrupt the repository state.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It helps inspect changes, describe commits, create bookmarks instead of branches, fetch remote updates, rebase work, and push selected bookmarks.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/megumish/jj-skill/jj
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add megumish/jj-skill --skill jj
Clone the repo
git clone --depth 1 https://github.com/megumish/jj-skill

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for jj

README.md
[![agentmods](https://agentmods.dev/badge/skills/megumish/jj-skill/jj.svg)](https://agentmods.dev/skills/megumish/jj-skill/jj)
Your own site
<a href="https://agentmods.dev/skills/megumish/jj-skill/jj"><img src="https://agentmods.dev/badge/skills/megumish/jj-skill/jj.svg" alt="Measured on agentmods" height="20"></a>
Per session 78 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,163 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00078 $0.01163
Opus 5 $0.00039 $0.00581
Sonnet 5 $0.00016 $0.00233
Haiku 4.5 $0.00008 $0.00116

Measured 8d ago against content hash 900098ae68f0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

jj scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/jj/SKILL.md · 133 lines

How it starts

The opening of the file, as written. The whole thing — 133 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Jujutsu (jj) Version Control Guide

CRITICAL: This is NOT git

This repository uses jujutsu (jj) as its version control system, NOT git.

  • NEVER use git commands (git add, git commit, git push, git branch, etc.)
  • Using git commands directly can corrupt the repository state
  • jj manages the underlying git repository internally — all operations go through jj

Git to jj Mapping

If you know git, use this table to find the jj equivalent:

Git command jj equivalent Notes
git status jj status Show changed files
git diff jj diff Show working copy changes
git log jj log Show commit history
git show <rev> jj show <rev> Show a specific commit
git add + git commit jj describe -m "msg" No staging needed; changes are auto-tracked
git branch <name> jj bookmark create <name> Bookmarks replace branches
git checkout -b <name> jj new + jj bookmark create <name> Create new change, then bookmark it
git push jj git push -b <bookmark> Must specify bookmark
git pull jj git fetch + jj rebase -o main@origin Fetch then rebase
git stash Not needed Every change is already a commit
git rebase -i jj rebase -o <dest> Non-interactive by default
git reset jj restore / jj abandon Restore files or abandon changes

Commands to Avoid

Command Status Reason Use instead
git * PROHIBITED jj is the VCS; git commands can corrupt state Corresponding jj command
jj commit PROHIBITED Splits working copy in confusing ways jj new + jj describe
jj squash -r <rev> RESTRICTED Risk of merging into unintended commit Only bare jj squash (squash into parent) is allowed

jj squash without -r is safe — it squashes the current change into its parent, which is a common and useful operation.

Reading Repository State

jj status          # Changed files in working copy
jj diff            # Diff of working copy changes
jj diff -r <rev>   # Diff of a specific revision
jj log             # Commit history (default revset)
jj log -r 'all()'  # Full history
jj show            # Show current commit details
jj show <rev>      # Show specific commit details

Read the full file on GitHub · 133 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 133 lines · 78 tokens per session scan A 900098ae68f0

Subscribe to this mod's changes

jj is a skill published in the GitHub repository megumish/jj-skill (5 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 78 tokens to every session and 1,163 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.