Parallel - Concurrent Execution

Run multiple Ralph loops concurrently for independent tasks.

Quick Start

/parallel "fix auth errors" "fix api errors" "fix ui errors"
ralph parallel task1 task2 task3

When to Use

Good for Parallel

• Independent file changes
• Multiple module fixes
• Batch reviews
• Different analysis types

Must Be Sequential

• Dependent changes
• Same file modifications
• Order-dependent operations
• Shared state changes

Workflow

1. Spawn Parallel Agents

# Launch multiple background agents
Task:
  subagent_type: "code-reviewer"
  model: "sonnet"
  run_in_background: true
  prompt: "Review auth module"

Task:
  subagent_type: "code-reviewer"
  model: "sonnet"
  run_in_background: true
  prompt: "Review api module"

Task:
  subagent_type: "code-reviewer"
  model: "sonnet"
  run_in_background: true
  prompt: "Review ui module"

2. Monitor Progress

# Check each task
TaskOutput:
  task_id: "<auth-task>"
  block: false

TaskOutput:
  task_id: "<api-task>"
  block: false

3. Aggregate Results

# Wait for all to complete
TaskOutput:
  task_id: "<auth-task>"
  block: true

TaskOutput:
  task_id: "<api-task>"
  block: true

Parallel Patterns

Review Pattern

# Parallel reviews with different focus
/parallel "security review src/" "performance review src/" "quality review src/"

Fix Pattern

# Parallel fixes for different modules
/parallel "fix auth errors" "fix api errors" "fix db errors"

Analysis Pattern

# Parallel analysis tasks
/parallel "analyze complexity" "analyze coverage" "analyze dependencies"

Isolation

Each parallel task runs with:

• Separate context (context: fork)
• Independent iteration counter
• Own quality gates
• Isolated file access

Result Aggregation

All Succeed

• Aggregate changes
• Run global gates
• VERIFIED_DONE

Partial Success

• Report failures
• Keep successful changes
• Retry failed tasks

All Fail

• Report all errors
• Analyze patterns
• Sequential retry

Integration

• Used for independent sub-tasks
• Each parallel task follows Ralph Loop
• Results feed back to orchestrator

Anti-Patterns

• Never run parallel on same files
• Never exceed 5 concurrent agents
• Never ignore partial failures
• Never skip aggregation step