Spawn Parallel Skill Skill

Spawn Parallel Skill

Pattern for spawning and coordinating parallel subagents.

When to Load This Skill

You have multiple independent tasks
Tasks don't depend on each other's output
You want to maximize concurrency

Spawning Pattern

1. Identify Independent Tasks

Tasks are independent if:

No data dependencies between them
No file conflicts (different files or read-only)
Can complete in any order

2. Prepare Contexts

Each subagent needs minimal, focused context:

{"task":{"id":"unique_id","description":"specific task"},"context_files":["only relevant files"],"boundaries":{"owns":["files this agent can modify"],"reads":["files for reference"]},"output_path":"memory/tasks/{id}/output.json"}

3. Spawn All at Once

Use multiple Task calls in single response:

Task(subagent_type: "implementer", model: "sonnet", prompt: "Task 1...")
Task(subagent_type: "implementer", model: "sonnet", prompt: "Task 2...")
Task(subagent_type: "implementer", model: "sonnet", prompt: "Task 3...")

Subagent Type Reference (Custom Dotagent Agents): | Type | Model | Use For | |------|-------|---------| | explorer | haiku | Fast codebase scouting | | implementer | sonnet | Focused code writing | | verifier | haiku | Independent verification | | tester | haiku | Test execution |

Note: These are custom dotagent agents (lowercase). Built-in Claude Code agents like Explore and Plan (capitalized) have different behavior.

4. Collect and Validate

After all complete:

Check each output file exists
Validate against schema
Handle failures (retry or escalate)

Coordination Rules

Prevent Conflicts

Define clear file ownership per agent
Use contracts for shared interfaces
Read-only access to shared resources

Handle Failures

Individual failures don't fail the batch. Apply recovery strategies from @.claude/skills/error-recovery/SKILL.md:

FOR each failed task in batch:
  IF output malformed/timeout:
    → Simple Retry (same prompt, up to 3x)
  ELIF agent said "unclear"/"don't understand":
    → Context Enhancement (add files, clarify)
  ELIF partial completion:
    → Scope Reduction (split into subtasks)
  ELIF boundary/contract violation:
    → Escalation (spawn contract-resolver)
  ELIF 3+ attempts failed:
    → Abort, record failure, continue with others

Retry with Context Enhancement Example:

Task(
  subagent_type: "implementer",
  model: "sonnet",
  prompt: |
    ## RETRY - Previous attempt failed
    Error: "Unclear how to connect to database"

    ## Additional Context
    See database config: @src/config/database.ts
    Connection pattern: @src/services/db-connection.ts

    ## Original Task
    {original_task_description}

    Output: memory/tasks/{id}/output.json
)

Example: Parallel Explorers

# Spawn 3 custom explorer agents in parallel
Task(
  subagent_type: "explorer",  # Custom dotagent agent
  model: "haiku",
  prompt: "Explore authentication code. Return compact JSON with findings."
)
Task(
  subagent_type: "explorer",
  model: "haiku",
  prompt: "Explore API routes. Return compact JSON with findings."
)
Task(
  subagent_type: "explorer",
  model: "haiku",
  prompt: "Explore database models. Return compact JSON with findings."
)

All run concurrently, results collected when all complete.

Example: Mixed Agent Types

# Parallel implementation with different boundaries
Task(
  subagent_type: "implementer",
  model: "sonnet",
  prompt: |
    Task: Add user validation
    Boundaries: owns=[src/validators/user.ts], reads=[src/types/]
    Output: memory/tasks/task-001/output.json
)
Task(
  subagent_type: "implementer",
  model: "sonnet",
  prompt: |
    Task: Add email service
    Boundaries: owns=[src/services/email.ts], reads=[src/config/]
    Output: memory/tasks/task-002/output.json
)

Agent Skills: Spawn Parallel Skill

Install this agent skill to your local

Skill Files