parallel-execution

# Parallel Execution Patterns

## Core Concept

Parallel execution spawns multiple subagents simultaneously using the Task tool with `run_in_background: true`. This enables N tasks to run concurrently, dramatically reducing total execution time.

**Critical Rule**: ALL Task calls MUST be in a SINGLE assistant message for true parallelism. If Task calls are in separate messages, they run sequentially.

## Execution Protocol

### Step 1: Identify Parallelizable Tasks

Before spawning, verify tasks are independent:
- No task depends on another's output
- Tasks target different files or concerns
- Can run simultaneously without conflicts

### Step 2: Prepare Dynamic Subagent Prompts

Each subagent receives a custom prompt defining its role:

```
You are a [ROLE] specialist for this specific task.

Task: [CLEAR DESCRIPTION]

Context:
[RELEVANT CONTEXT ABOUT THE CODEBASE/PROJECT]

Files to work with:
[SPECIFIC FILES OR PATTERNS]

Output format:
[EXPECTED OUTPUT STRUCTURE]

Focus areas:
- [PRIORITY 1]
- [PRIORITY 2]
```

### Step 3: Launch All Tasks in ONE Message

**CRITICAL**: Make ALL Task calls in the SAME assistant message:

```
I'm launching N parallel subagents:

[Task 1]
description: "Subagent A - [brief purpose]"
prompt: "[detailed instructions for subagent A]"
run_in_background: true

[Task 2]
description: "Subagent B - [brief purpose]"
prompt: "[detailed instructions for subagent B]"
run_in_background: true

[Task 3]
description: "Subagent C - [brief purpose]"
prompt: "[detailed instructions for subagent C]"
run_in_background: true
```

### Step 4: Retrieve Results with TaskOutput

After launching, retrieve each result:

```
[Wait for completion, then retrieve]

TaskOutput: task_1_id
TaskOutput: task_2_id
TaskOutput: task_3_id
```

### Step 5: Synthesize Results

Combine all subagent outputs into unified result:
- Merge related findings
- Resolve conflicts between recommendations
- Prioritize by severity/importance
- Create actionable summary

## Dynamic Subagen