/parallel

Worktree Parallel

You are executing the /hydra:parallel command. Start multiple agents simultaneously in different worktrees.

Arguments

$ARGUMENTS is parsed as a pipe-separated list of tasks:

worktree1:prompt1 | worktree2:prompt2 | worktree3:prompt3

Example:

/hydra:parallel feature-a:Implement login | feature-b:Implement logout | feature-c:Write tests

Process

1. Parse Tasks

Split $ARGUMENTS at | and parse each part:

# Example parsing
echo "$ARGUMENTS" | tr '|' '\n' | while read task; do
  WORKTREE=$(echo "$task" | cut -d':' -f1 | xargs)
  PROMPT=$(echo "$task" | cut -d':' -f2- | xargs)
  echo "Worktree: $WORKTREE, Prompt: $PROMPT"
done

2. Validate All Worktrees

For each task:

git worktree list | grep -qE "$WORKTREE|hydra/$WORKTREE"

If a worktree is missing, offer to create it:

The following worktrees do not exist:
  - feature-x
  - feature-y

Should I create them? (Branches will be forked from main)

If yes, create missing worktrees:

# Determine paths (always relative to repo root, not CWD)
REPO_ROOT=$(git rev-parse --show-toplevel)
REPO_NAME=$(basename "$REPO_ROOT")
WORKTREES_DIR="$(dirname "$REPO_ROOT")/${REPO_NAME}-worktrees"

for WT in feature-x feature-y; do
  git worktree add -b "hydra/$WT" "$WORKTREES_DIR/$WT"
done

3. Start All Agents in Parallel

IMPORTANT: Use a single response with multiple Task tool calls!

For each task, call Task tool with:

subagent_type: general-purpose
run_in_background: true
prompt: [like in /hydra:spawn]

All Task calls must be in ONE response for true parallelism.

4. Collect Results

After starting all agents:

Parallel agents started:

  Worktree      | Agent ID        | Task
  --------------|-----------------|---------------------------
  feature-a     | agent-abc123    | Implement login
  feature-b     | agent-def456    | Implement logout
  feature-c     | agent-ghi789    | Write tests

All agents running in background.

Next steps:
  - /hydra:status                # Progress of all worktrees
  - TaskOutput agent-abc123      # Result of one agent
  - /hydra:merge feature-a       # When done: merge individually

Input Format Alternatives

If JSON preferred:

[
  {"worktree": "feature-a", "prompt": "Implement login"},
  {"worktree": "feature-b", "prompt": "Implement logout"}
]

If line breaks:

feature-a: Implement login
feature-b: Implement logout
feature-c: Write tests

Detect the format automatically and parse accordingly.

Notes

• Maximum parallelism: ~3-5 agents (system limit)
• Each agent works in isolation
• No Git conflicts between agents
• Results can finish in any order