jj-sync

A Jujutsu version-control command that fetches updates from remote repositories and rebases your work onto the main line of development. Rebasing puts your changes on top of newer project changes.

In plain words
What is it for?
Use it to fetch from all remotes, rebase onto the trunk, inspect conflicts, and receive a status summary.
Why use it?
It groups the routine steps for bringing a local project up to date and reports any merge conflicts that need attention.

Command

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.

agentmods
npx agentmods add commands/musingfox/cc-plugins/jj-sync
Clone the repo
git clone --depth 1 https://github.com/musingfox/cc-plugins
Per session 20 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 491 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00020 $0.00491
Opus 5 $0.00010 $0.00246
Sonnet 5 $0.00004 $0.00098
Haiku 4.5 $0.00002 $0.00049

Measured yesterday against content hash 5c4cf3165e20, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

jj-sync 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 yesterday.

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.

jj/commands/jj-sync.md · 76 lines

What it actually says

jj-sync — Sync Workflow

Fetch latest changes from remotes and rebase the working copy onto trunk.

Environment Detection

# Verify jj repo
if [ ! -d ".jj" ] && ! jj root 2>/dev/null; then
  echo "NOT_JJ_REPO"
fi

# Check colocated
if [ -d ".git" ] || git rev-parse --git-dir 2>/dev/null; then
  echo "COLOCATED"
else
  echo "NATIVE_JJ"
fi

If NOT a jj repo, inform the user and stop.

Colocated Mode Workflow

Step 1: Fetch from All Remotes

jj git fetch --all-remotes

Report what was fetched (new bookmarks, updated refs).

Step 2: Rebase onto Trunk

jj rebase -d 'trunk()'

If the rebase has conflicts, report them clearly.

Step 3: Conflict Summary

jj log --revisions "conflict()"

If conflicts exist, explain:

  • Which changes have conflicts
  • Suggest jj resolve or manual resolution
  • Offer to show the conflicted files

Step 4: Status Report

Show a summary:

## Sync Complete

**Fetched**: [remotes fetched from]
**Rebased onto**: [trunk change]
**Conflicts**: [count, or "None"]

Native jj Mode

If native (no git):

  1. Check if there are any remotes configured: jj config get revsets.trunk
  2. If no remotes, inform user: "No git remotes detected. This repo appears to be native jj without remote configuration."
  3. If remotes exist via other means, attempt the sync workflow.

Error Handling

  • No network: If fetch fails with network error, report and skip to local status
  • No trunk: If trunk() revset fails, ask the user which revision to rebase onto
  • Divergent bookmarks: Report divergent bookmarks and suggest resolution
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. yesterday First seen · 76 lines · 20 tokens per session scan A 5c4cf3165e20

Subscribe to this mod's changes

jj-sync is a command published in the GitHub repository musingfox/cc-plugins (2 stars, last pushed 2d ago), licensed MIT. It adds 20 tokens to every session and 491 once invoked, about $0.0001 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.