Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add tommymorgan/claude-plugins/plugin install tommymorganWrote 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.
[](https://agentmods.dev/skills/tommymorgan/claude-plugins/jj)<a href="https://agentmods.dev/skills/tommymorgan/claude-plugins/jj"><img src="https://agentmods.dev/badge/skills/tommymorgan/claude-plugins/jj.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00038 | $0.02198 |
| Opus 5 | $0.00019 | $0.01099 |
| Sonnet 5 | $0.00008 | $0.00440 |
| Haiku 4.5 | $0.00004 | $0.00220 |
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 6d 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.
How it starts
The opening of the file, as written. The whole thing — 230 lines — stays where its author put it; the contents beside it link to each section on GitHub.
jj (Jujutsu VCS) Guide
When a .jj/ directory is present, the repository is managed by jj. Use jj commands for all version control operations. Never use raw git commands.
Communication Convention
Use jj commands but speak in git terminology. Since the canonical remote is typically a git repository (GitHub/GitLab), use familiar git terms when communicating:
| jj term | Say this instead |
|---|---|
| change | commit |
| bookmark | branch |
@ (working copy) |
current commit / working copy |
@- (parent) |
parent commit |
| describe | set commit message |
This keeps communication clear for all team members regardless of their jj familiarity.
Critical Safety Rules
Never use raw git commands
In a colocated jj+git repository, raw git commands bypass jj's operation log and can corrupt repository state. The following are forbidden:
git commit— usejj describe+jj newgit add— not needed, jj auto-tracks all changesgit checkout— usejj editorjj newgit branch— usejj bookmarkgit stash— not needed, justjj newgit merge— usejj new commit1 commit2(merge commit)git rebase— usejj rebase
Exception: gh CLI is acceptable (it uses git internally for PR operations).
Always create a new commit before editing pushed code
If the current commit (@) has a branch that has been pushed to the remote, do not edit files directly. This rewrites history and causes force pushes.
Instead:
- Run
jj newto create a fresh empty commit on top - Then make edits
Always pass -m to commands that open an editor
Commands like jj squash, jj split, and jj commit open an interactive editor (vim) to compose a message when no -m flag is provided. Claude Code runs in a non-interactive terminal, so the editor fails with Error reading input, exiting... and the command aborts.
Always pass -m "message" to these commands:
# ✅ GOOD — non-interactive
jj squash --from <rev> --into <rev> -m "combined commit message"
jj squash -m "squash into parent"
# ❌ BAD — opens vim, fails in non-interactive terminal
jj squash --from <rev> --into <rev>
jj squash
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.
- 6d ago First seen · 230 lines · 38 tokens per session scan A d437ff3f4989
jj is a skill published in the GitHub repository tommymorgan/claude-plugins (4 stars, last pushed 1mo ago), licensed MIT. It adds 38 tokens to every session and 2,198 once invoked, about $0.0002 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.
Other skills, from other repositories
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
local-ai-agents
Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…
chronicle
Analyze Copilot session history for standup reports, usage tips, session search, and session reindexing. Use when the user asks for a standup, daily summary, usage tips, workflow recommendations, wants to search or find past sessions by keyword/file/PR, wants to reindex their session store, or asks about deleting…
chat-pet-sprite-creation
Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.
cpu-profile-analysis
Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…
next-cache-components-adoption
Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…