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name: vcs-detect description: Detect whether the current project uses jj (Jujutsu) or git for version control. Run this BEFORE any VCS command to use the correct tool.

VCS Detection Skill

Detect the version control system in use before running any VCS commands.

Why This Matters

• jj (Jujutsu) and git have different CLIs and workflows
• Running git commands in a jj repo (or vice versa) causes errors
• Some repos use jj with git colocated (both .jj/ and .git/ exist)

Detection Logic

Priority order (check in sequence):

1. Check for .jj/ directory - If exists, use jj
2. Check for .git/ directory - If exists, use git
3. Neither found - Not a VCS-managed directory

Copyif .jj/ exists -> use jj
else if .git/ exists -> use git
else -> no VCS detected

Detection Command

Run this single command to detect VCS:

Copyif [ -d ".jj" ]; then echo "jj"; elif [ -d ".git" ]; then echo "git"; else echo "none"; fi

Command Mappings

Usage

Before any VCS operation:

1. Run detection command
2. Use appropriate CLI based on result
3. If none, warn user directory is not version controlled

Example Integration

CopyUser: Show me the git log
Agent: [Runs detection] -> Result: jj
Agent: [Runs `jj log` instead of `git log`]

Colocated Repos

When both .jj/ and .git/ exist, the repo is "colocated":

• jj manages the working copy
• git is available for compatibility (GitHub, etc.)
• Always prefer jj commands in colocated repos