implementation-manager

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_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.

Migration note (P1601 — 2026-Q1): The 8-tool SAM MCP API has been consolidated into 3 distributed-safe tools: sam_plan (plan-level operations), sam_task (task-level operations), and sam_active_task (session context registration). The deprecated tools listed below remain as compatibility shims — they still work but new code must use the consolidated API.

Deprecated tool	Consolidated replacement
sam_list	sam_plan
sam_status	sam_plan
sam_ready	sam_plan
sam_read (plan-level)	sam_plan
sam_read (task-level)	sam_task
sam_claim	sam_task
sam_state	sam_task
sam_update	sam_plan
sam_create	sam_plan

Commands

list

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

mcp__plugin_dh_sam__sam_list()

Output:

{
  "features": [
    {
      "slug": "prepare-host",
      "task_file": "tasks-1-prepare-host.md",
      "path": "~/.dh/projects/{project-slug}/plan/tasks-1-prepare-host.md"
    }
  ],
  "count": 1
}

status

Get detailed status for a specific feature:

mcp__plugin_dh_sam__sam_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_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_read(plan="P1")

claim

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

mcp__plugin_dh_sam__sam_claim(plan="P1", task="T01")

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_update(plan="P1", context="Context Manifest content")

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

Dependency Resolution

A task is "ready" when:

1. Status is not-started
2. All dependencies have status complete (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 (deprecated: sam_status(plan="P{N}"))
2. Find ready tasks via mcp__plugin_dh_sam__sam_plan (deprecated: sam_ready(plan="P{N}"))
3. Launch appropriate agents based on task's agent field
4. Update timestamps via hook scripts when tasks start/complete