implementation-manager

name	implementation-manager
description	Manages feature implementation task state via SAM MCP tools. Use when querying task status, listing ready tasks, claiming tasks for execution, updating task timestamps, or coordinating multi-task feature rollout. Activated by the /dh:execution orchestrator to track progress — also activates directly when managing task files or configuring hook profiles.
user-invocable	false
disable-model-invocation	false

Implementation Manager

Current Task Context

Available features (if in project with plan/ directory): !uv run sam list 2>/dev/null || echo '{"features": [], "count": 0, "message": "Not in a project with task files"}'

Active task context (if any): !python3 -c "from dh_paths import context_dir; import os; cdir = context_dir(os.environ.get('CLAUDE_CODE_SESSION_ID', '')); files = list(cdir.glob('active-task-*.json')) if cdir.exists() else []; print(files[0].read_text() if files else 'No active task')" 2>/dev/null || echo "No active task"

A skill for querying and managing feature implementation task files. Provides programmatic access to task status for orchestrators coordinating multi-step feature implementations.

SAM MCP Tool Usage

The SAM MCP server (mcp__plugin_dh_sam__*) is the primary interface for all SAM task file operations. The uv run sam CLI is available as fallback when MCP is unavailable.

Commands

list

List all features with task files in the project's plan/ directory:

mcp__plugin_dh_sam__sam_plan(config={"action": "list"})

Output:

{
  "features": [
    {
      "slug": "prepare-host",
      "task_file": "tasks-1-prepare-host.md"
    }
  ],
  "count": 1
}

status

Get detailed status for a specific feature:

mcp__plugin_dh_sam__sam_plan(config={"action": "status"}, plan="P1")

Output:

{
  "feature": "prepare-host",
  "task_file": "tasks-1-prepare-host.md",
  "total_tasks": 8,
  "completed": 8,
  "in_progress": 0,
  "not_started": 0,
  "ready_tasks": [],
  "tasks": [
    {
      "id": "1.1",
      "name": "Add Data Models to shared/models.py",
      "status": "complete",
      "dependencies": [],
      "agent": null,
      "priority": 1,
      "complexity": "low"
    }
  ]
}

ready-tasks

List tasks ready for execution (dependencies satisfied):

mcp__plugin_dh_sam__sam_plan(config={"action": "ready"}, plan="P1")

Output:

{
  "feature": "prepare-host",
  "ready_tasks": [
    {
      "id": "1.3",
      "name": "Create core/prepare.py Business Logic",
      "agent": "python-cli-architect"
    }
  ],
  "count": 1
}

read

Read full plan data including task fields and context:

mcp__plugin_dh_sam__sam_plan(config={"action": "read"}, plan="P1")

claim

Claim a task in-progress (prevents duplicate dispatch):

mcp__plugin_dh_sam__sam_task(plan="P1", task="T01", config={"action": "claim"})

Returns {"claimed": false, "error": "..."} if task is already claimed or not found.

update

Update plan-level fields (e.g., context manifest):

mcp__plugin_dh_sam__sam_plan(config={"action": "update", "context": "Context Manifest content"}, plan="P1")

Task File Format

Task files use YAML frontmatter format. The SAM MCP tools validate all fields — do not parse task files directly.

---
task: T01
title: "Task title"
status: not-started
agent: python-cli-architect
dependencies: []
priority: 1
complexity: medium
accuracy-risk: low
skills: []
---

Status Values

• not-started — task has not been started
• in-progress — task is claimed and being executed
• complete — task is done
• blocked — task cannot proceed
• deferred — task is intentionally postponed
• skipped — task was bypassed without execution
• failed — task execution ended in failure

Dependency Resolution

A task is "ready" when:

1. Status is not-started
2. All dependencies have status complete, deferred, or skipped (or no dependencies)

Hook Integration

The task_status_hook.py script provides automated task status tracking via Claude Code hooks.

Hook Configuration

Command	Hook Event	Matcher	Purpose
/dh:execution	SubagentStop	(all)	Mark task COMPLETE, add Completed timestamp
/dh:start-task	PostToolUse	Write|Edit|Bash	Update LastActivity timestamp during execution

How It Works

SubagentStop (Task Completion):

When /dh:execution launches a sub-agent via /start-task {task_file} --task {id}, the SubagentStop hook fires when the sub-agent completes. The hook script:

1. Parses the original prompt to extract task file path and task ID
2. Updates task status from IN PROGRESS to COMPLETE
3. Adds **Completed**: {ISO timestamp} to the task section

PostToolUse (Activity Tracking):

When /dh:start-task runs, it creates a context file at ~/.dh/projects/{slug}/context/active-task-{session_id}.json (resolved via dh_paths.context_dir(session_id)) containing the task file path and task ID. On each Write, Edit, or Bash operation, the PostToolUse hook:

1. Reads the context file to identify the active task
2. Updates **LastActivity**: {ISO timestamp} in the task section

Timestamp Field Responsibilities

Field	Added By	When
**Started**	Agent (via /dh:start-task)	When agent begins work on task
**Completed**	Hook (SubagentStop)	When sub-agent finishes
**LastActivity**	Hook (PostToolUse)	On each Write, Edit, or Bash call

Hook Runtime Profile Controls

The task_status_hook.py script supports environment-variable-based profile controls that adjust hook behavior without editing SKILL.md files.

CLAUDE_SKILLS_HOOK_PROFILE

Controls which hook handlers run. Case-sensitive lowercase. Default when unset or empty: standard.

• minimal — PostToolUse (LastActivity updates) is skipped entirely. SubagentStop (task completion) runs normally. Use this to reduce I/O during task execution when activity timestamps are not needed.
• standard — All handlers run. This is the current default behavior and is backward compatible with sessions that do not set the variable.
• strict — All handlers run. SubagentStop additionally performs pre-completion validation checks and emits warnings to stderr. Warnings are observational only — they do not prevent task completion. Strict checks verify that the task was claimed (status was in-progress before completion) and that acceptance criteria were defined (non-empty).

Invalid values produce a warning to stderr and fall back to standard.

CLAUDE_SKILLS_DISABLED_HOOKS

Comma-separated list of hook IDs to disable. Each ID is stripped of whitespace. Empty segments are excluded. Unknown IDs are silently ignored for forward compatibility. Default when unset or empty: no hooks disabled.

Hook IDs for this script:

• task-status:post-tool-use — the PostToolUse handler (LastActivity timestamp updates)
• task-status:subagent-stop — the SubagentStop handler (task completion marking)

Disabled hooks take precedence over profile. If both CLAUDE_SKILLS_HOOK_PROFILE=strict and CLAUDE_SKILLS_DISABLED_HOOKS=task-status:subagent-stop are set, SubagentStop is skipped entirely (no strict checks run).

Disabled hooks exit 0 (Claude Code treats non-zero hook exit as an error that kills the hook chain).

Examples

# Skip PostToolUse activity tracking (reduces I/O during task execution)
export CLAUDE_SKILLS_HOOK_PROFILE=minimal

# Enable strict pre-completion validation warnings
export CLAUDE_SKILLS_HOOK_PROFILE=strict

# Disable a specific hook by ID
export CLAUDE_SKILLS_DISABLED_HOOKS=task-status:post-tool-use

# Disable multiple hooks
export CLAUDE_SKILLS_DISABLED_HOOKS="task-status:post-tool-use,task-status:subagent-stop"

Integration with /execution

The /dh:execution orchestrator uses this skill to:

1. Query task file status via mcp__plugin_dh_sam__sam_plan
2. Find ready tasks via mcp__plugin_dh_sam__sam_plan
3. Launch appropriate agents based on task's agent field
4. Update timestamps via hook scripts when tasks start/complete