Task Dependency Patterns

Overview

• TaskCreate: Create new tasks with subject, description, and activeForm
• TaskUpdate: Update status (pending → in_progress → completed), set dependencies
• TaskGet: Retrieve full task details including blockers
• TaskList: View all tasks with status and dependency summary

When to Use

• Breaking down complex multi-step implementations
• Coordinating parallel work across multiple files
• Tracking progress on large features
• Managing dependencies between related changes
• Providing visibility into work status

Key Patterns

1. Task Decomposition

Feature: Add user authentication

Tasks:
#1. [pending] Create User model
#2. [pending] Add auth endpoints (blockedBy: #1)
#3. [pending] Implement JWT tokens (blockedBy: #2)
#4. [pending] Add auth middleware (blockedBy: #3)
#5. [pending] Write integration tests (blockedBy: #4)

2. Dependency Chains

addBlockedBy

// Task #3 cannot start until #1 and #2 complete
{"taskId": "3", "addBlockedBy": ["1", "2"]}

3. Status Workflow

pending → in_progress → completed
   ↓           ↓
(unblocked)  (active)

pending/in_progress → deleted (CC 2.1.20)

• pending: Task created but not started
• in_progress: Actively being worked on
• completed: Work finished and verified
• deleted: Task removed (CC 2.1.20) - permanently removes the task

Task Deletion (CC 2.1.20)

status: "deleted"

// Delete a task
{"taskId": "3", "status": "deleted"}

• Orphaned tasks whose blockers have all failed
• Tasks superseded by a different approach
• Duplicate tasks created in error
• Tasks from a cancelled pipeline

• Tasks that might be retried later (keep as pending)
• Tasks with useful history (mark completed instead)
• Tasks blocked by in_progress work (wait for resolution)

4. activeForm Pattern

Agent Teams (CC 2.1.33+)

Team Workflow

1. TeamCreate("my-feature")           → Creates team + shared task list
2. TaskCreate(subject, description)    → Add tasks to shared list
3. Task(prompt, team_name, name)       → Spawn teammates
4. TaskUpdate(owner: "teammate-name")  → Assign tasks
5. SendMessage(type: "message")        → Direct teammate communication
6. SendMessage(type: "shutdown_request") → Graceful shutdown

When to Use Teams vs Task Tool

Team Task Patterns

# Spawn teammate into shared task list
Task(
  prompt="You are the backend architect...",
  team_name="my-feature",
  name="backend-architect",
  subagent_type="backend-system-architect"
)

# Teammate claims and works tasks
TaskList → find unblocked, unowned tasks
TaskUpdate(taskId, owner: "backend-architect", status: "in_progress")
# ... do work ...
TaskUpdate(taskId, status: "completed")
TaskList → find next task

Peer Messaging

# Direct message between teammates
SendMessage(type: "message", recipient: "frontend-dev",
  content: "API contract ready: GET /users/:id returns {...}",
  summary: "API contract shared")

# Broadcast to all (use sparingly)
SendMessage(type: "broadcast",
  content: "Breaking change: auth header format changed",
  summary: "Breaking auth change")

Anti-Patterns

• Creating tasks for trivial single-step work
• Circular dependencies (A blocks B, B blocks A)
• Leaving tasks in_progress when blocked
• Not marking tasks completed after finishing
• Using broadcast for messages that only concern one teammate
• Spawning teams for simple sequential work (use Task tool instead)

Related Skills

• worktree-coordination

  - Multi-instance task coordination across git worktrees

• implement

  - Implementation workflow with task tracking and progress updates

• verify

  - Verification tasks and completion checklists

• fix-issue

  - Issue resolution with hypothesis-based RCA tracking

• brainstorming

  - Design exploration with parallel agent tasks

References

• Dependency Tracking
• Status Workflow
• Multi-Agent Coordination