Agent Orchestration — Todo-Driven Parallel Execution

You are orchestrating a complex task by decomposing it into tracked subtasks, dispatching parallel agents, and coordinating dependencies until completion. Shodh-memory todos are your task graph. Claude Code's Task tool is your agent spawner. Hooks handle the automation.

Phase 1: Decompose

Break the user's request into 3-10 concrete, independently executable subtasks.

Create the project

add_project(name="orch-{kebab-case-summary}")

The project auto-generates a prefix (e.g., ORCH). All todos in this project use that prefix for short IDs like ORCH-1, ORCH-2.

Create todos with dependencies

For each subtask, create a todo in the project:

Independent tasks (can run immediately):

add_todo(
  content="Clear, specific description of what this subtask produces",
  project="orch-{name}",
  priority="high",
  tags=["orchestration", "batch:1"]
)

Dependent tasks (must wait for others):

add_todo(
  content="Description of dependent work",
  project="orch-{name}",
  status="blocked",
  blocked_on="ORCH-1,ORCH-3",
  tags=["orchestration", "batch:2"]
)

The blocked_on field is comma-separated short IDs. The batch:N tag groups tasks by execution wave.

Dependency rules

• A task blocked on "ORCH-1,ORCH-3" cannot start until BOTH are done
• Keep dependency chains shallow (max 3-4 levels deep)
• Maximize parallelism — identify tasks that are truly independent
• Never create circular dependencies

Present the plan

Show the user the task graph before executing:

Project: orch-refactor-auth (ORCH)

Batch 1 (parallel):
  ORCH-1: [todo] Extract JWT utilities into auth/tokens.ts
  ORCH-2: [todo] Create password hashing module

Batch 2 (after batch 1):
  ORCH-3: [blocked on ORCH-1] Update login endpoint
  ORCH-4: [blocked on ORCH-1] Update token refresh endpoint
  ORCH-5: [blocked on ORCH-2] Update registration endpoint

Batch 3 (after batch 2):
  ORCH-6: [blocked on ORCH-3,ORCH-4,ORCH-5] Integration tests

Wait for user approval before dispatching.

Phase 2: Dispatch

Find unblocked work

list_todos(project="orch-{name}", status=["todo"])

For each unblocked todo:

1. Mark it in-progress:

update_todo(todo_id="ORCH-N", status="in_progress")

2. Spawn a Task agent with the todo tag in the prompt:

CRITICAL: Every Task prompt MUST start with [ORCH-TODO:ORCH-N] where N is the todo's sequence number. The PostToolUse hook extracts this tag to automatically complete the todo and unblock dependents.

Task(
  description="ORCH-N: brief summary",
  prompt="[ORCH-TODO:ORCH-N] Full detailed instructions for the agent...",
  subagent_type="general-purpose"
)

3. Spawn independent tasks in parallel — make multiple Task calls in a single response.

Choose the right agent type

Agent Type	Best For
Explore	Research, codebase exploration, finding patterns
Plan	Architecture design, trade-off analysis
Bash	Running commands, builds, deployments
general-purpose	Code changes, implementation, multi-step work

Include sufficient context in each prompt

Each agent runs in isolation. Include in every Task prompt:

• What files to look at or modify
• What the expected output/deliverable is
• Any constraints or patterns to follow
• Context from previously completed tasks (copy relevant resolution comments)

Phase 3: Monitor & Continue

After agents return, the PostToolUse hook automatically:

• Adds the agent's result as a Resolution comment on the matching todo
• Completes the todo
• Unblocks dependent todos (removes from blocked_on, changes status to todo)

Check project state

list_todos(project="orch-{name}")

Review the status:

• done — completed by agents
• todo — newly unblocked, ready for next batch
• blocked — still waiting on dependencies
• in_progress — agents still running
• cancelled — failed permanently

Dispatch next batch

If there are todo status items, repeat Phase 2 for the next batch. Continue until all todos are done or cancelled.

Summarize results

When all todos are complete:

1. List all resolution comments to gather agent outputs
2. Synthesize a summary for the user
3. Note any cancelled tasks and why

Handling Failures

When a Task agent returns an error or incomplete result:

1. Add a Progress comment documenting the failure:

add_todo_comment(
  todo_id="ORCH-N",
  content="Agent failed: {error description}",
  comment_type="progress"
)

2. Retry (max 2 attempts) with additional context:

Task(
  prompt="[ORCH-TODO:ORCH-N] RETRY: Previous attempt failed because {reason}. {updated instructions}...",
  subagent_type="general-purpose"
)

3. If retry fails, cancel the todo:

update_todo(todo_id="ORCH-N", status="cancelled", notes="Failed after 2 retries: {reason}")

4. Check if cancelled todo blocks other work — inform the user and ask how to proceed.

Cross-Session Continuity

If a session ends mid-orchestration, the todo state persists. On the next session:

1. Check for in-progress orchestration projects:

list_projects()
list_todos(project="orch-{name}")

2. Resume from where you left off — dispatch any todo status items.

Example

User: /orchestrate Add comprehensive error handling to the API layer

Planning:

Project: orch-api-error-handling (ORCH)

ORCH-1: [todo] Audit current error handling patterns across all handlers
ORCH-2: [todo] Design error response format and error codes enum
ORCH-3: [blocked on ORCH-1,ORCH-2] Implement centralized error middleware
ORCH-4: [blocked on ORCH-3] Update all handler functions to use new error types
ORCH-5: [blocked on ORCH-4] Add error handling integration tests

Batch 1 dispatch (parallel):

Task("[ORCH-TODO:ORCH-1] Explore the codebase and audit...", subagent_type="Explore")
Task("[ORCH-TODO:ORCH-2] Design an error response format...", subagent_type="Plan")

After batch 1 completes:

• Hook auto-completes ORCH-1 and ORCH-2
• Hook unblocks ORCH-3 (both blockers resolved)
• Claude dispatches ORCH-3

Continue until ORCH-5 is done.