spawn

Worktree Spawn

You are executing the /hydra:spawn command. Start an agent in an existing worktree.

Arguments

$ARGUMENTS is parsed as:

• First word: Worktree name
• Rest: Prompt for the agent

Example: feature-a Implement the new feature

• worktree: feature-a
• prompt: Implement the new feature

Process

1. Parse Arguments

# First word = Worktree
WORKTREE_NAME=$(echo "$ARGUMENTS" | awk '{print $1}')

# Rest = Prompt
AGENT_PROMPT=$(echo "$ARGUMENTS" | cut -d' ' -f2-)

If either is missing, show help:

Usage: /hydra:spawn {worktree} {prompt}

Example:
  /hydra:spawn feature-a "Implement login form"

2. Check if Worktree Exists

git worktree list | grep -E "$WORKTREE_NAME|hydra/$WORKTREE_NAME"

If not found:

Worktree '{name}' not found.

Options:
1. Create it first: /hydra:create {name}
2. Show available: /hydra:list

3. Determine Absolute Path

WORKTREE_PATH=$(git worktree list --porcelain | grep -B1 "$WORKTREE_NAME" | grep "worktree " | head -1 | cut -d' ' -f2-)

# Convert to absolute path
WORKTREE_PATH=$(cd "$WORKTREE_PATH" && pwd)

# Main checkout (first entry of the worktree list)
MAIN_CHECKOUT=$(git worktree list --porcelain | sed -n '1s/^worktree //p')

4. Start Agent with Task Tool

Use the Task tool with these parameters:

subagent_type: general-purpose
run_in_background: true (optional, depending on task)
prompt: [see below]

Construct agent prompt:

You are working in an isolated Git worktree.

IMPORTANT - Your working directory:
  {WORKTREE_PATH}

All file operations must be relative to this directory.
Use absolute paths or ensure you are in the correct directory.

Main checkout (READ-ONLY for you):
  {MAIN_CHECKOUT}

If something important is missing in your worktree (neither checked out, linked
nor copied - e.g. a rule file or local config), look it up read-only in the main
checkout. Never write, commit or run state-changing git commands there. Mention in
your report anything that should be added to the worktree files list.

Your task:
{AGENT_PROMPT}

When finished:
1. Commit your changes on the worktree branch (never push, never merge - the main agent does that)
2. Show git status and git log -3