Planner Skill

Thin wrapper that delegates plan creation to planner-agent subagent.

IMPORTANT: This skill implements the skill-internal postflight pattern. After the subagent returns, this skill handles all postflight operations (status update, artifact linking, git commit) before returning. This eliminates the "continue" prompt issue between skill return and orchestrator.

Context References

Reference (do not load eagerly):

Path: .claude/context/formats/return-metadata-file.md - Metadata file schema
Path: .claude/context/patterns/postflight-control.md - Marker file protocol
Path: .claude/context/patterns/file-metadata-exchange.md - File I/O helpers
Path: .claude/context/patterns/jq-escaping-workarounds.md - jq escaping patterns (Issue #1132)

Note: This skill is a thin wrapper with internal postflight. Context is loaded by the delegated agent.

Trigger Conditions

This skill activates when:

Task status is any non-terminal state (not completed, not abandoned)
/plan command is invoked
Implementation approach needs to be formalized

Execution Flow

Stage 1: Input Validation

Validate required inputs:

task_number - Must be provided and exist in state.json
Task status must allow planning

# Lookup task
task_data=$(jq -r --argjson num "$task_number" \
  '.active_projects[] | select(.project_number == $num)' \
  specs/state.json)

# Validate exists
if [ -z "$task_data" ]; then
  return error "Task $task_number not found"
fi

# Extract fields
task_type=$(echo "$task_data" | jq -r '.task_type // "general"')
status=$(echo "$task_data" | jq -r '.status')
project_name=$(echo "$task_data" | jq -r '.project_name')
description=$(echo "$task_data" | jq -r '.description // ""')

# Validate status (only block terminal states)
if [ "$status" = "completed" ] || [ "$status" = "abandoned" ]; then
  return error "Task is in terminal state [$status]"
fi

Stage 2: Preflight Status Update

Update task status to "planning" BEFORE invoking subagent.

The centralized script handles state.json, TODO.md task entry status marker, and TODO.md Task Order status marker atomically:

bash .claude/scripts/update-task-status.sh preflight $task_number plan $session_id

If the script exits non-zero, stop execution and return error. Exit code 2 indicates state.json failure; exit code 3 indicates TODO.md failure.

Stage 3: Create Postflight Marker

Create the marker file to prevent premature termination:

# Ensure task directory exists
padded_num=$(printf "%03d" "$task_number")
mkdir -p "specs/${padded_num}_${project_name}"

cat > "specs/${padded_num}_${project_name}/.postflight-pending" << EOF
{
  "session_id": "${session_id}",
  "skill": "skill-planner",
  "task_number": ${task_number},
  "operation": "plan",
  "reason": "Postflight pending: status update, artifact linking, git commit",
  "created": "$(date -u +%Y-%m-%dT%H:%M:%SZ)",
  "stop_hook_active": false
}
EOF

Stage 3a: Calculate Artifact Number

Read next_artifact_number from state.json and use (current-1) since plan stays in the same round as research:

# Read next_artifact_number from state.json
next_num=$(jq -r --argjson num "$task_number" \
  '.active_projects[] | select(.project_number == $num) | .next_artifact_number // 1' \
  specs/state.json)

# Plan uses (current - 1) to stay in the same round as research
# If next_artifact_number is 1 (no research yet), use 1
if [ "$next_num" -le 1 ]; then
  artifact_number=1
else
  artifact_number=$((next_num - 1))
fi

# Fallback for legacy tasks: count existing plan artifacts
if [ "$next_num" = "null" ] || [ -z "$next_num" ]; then
  padded_num=$(printf "%03d" "$task_number")
  count=$(ls "specs/${padded_num}_${project_name}/plans/"*[0-9][0-9]*.md 2>/dev/null | wc -l)
  artifact_number=$((count + 1))
fi

artifact_padded=$(printf "%02d" "$artifact_number")

Note: Plan does NOT increment next_artifact_number in state.json. Only research advances the sequence. Plan uses (current - 1) to share the same round number as the preceding research.

Stage 4a: Memory Retrieval (Auto)

Retrieve relevant memories from the memory system to inject into the delegation context.

Skip if: clean_flag is true in the delegation context (from --clean command flag).

# Check clean_flag
if [ "$clean_flag" != "true" ]; then
  memory_context=$(bash .claude/scripts/memory-retrieve.sh "$description" "$task_type" "" 2>/dev/null) || memory_context=""
fi

# memory_context will be empty string if:
# - clean_flag is true (skipped)
# - memory-index.json missing or empty
# - no keywords matched any entries
# - script exited with error

If memory_context is non-empty, it will be injected into the Stage 5 prompt alongside the format specification from Stage 4b. If empty, no memory block is injected.

Stage 4: Prepare Delegation Context

Prior plan discovery: Find the latest existing plan file (if any) to pass as reference context.

# Discover prior plan (if any)
padded_num=$(printf "%03d" "$task_number")
prior_plan_path=$(ls -1 "specs/${padded_num}_${project_name}/plans/"*.md 2>/dev/null | sort -V | tail -1)
# prior_plan_path will be empty if no prior plans exist

Prepare delegation context for the subagent:

{
  "session_id": "sess_{timestamp}_{random}",
  "delegation_depth": 1,
  "delegation_path": ["orchestrator", "plan", "skill-planner"],
  "timeout": 1800,
  "task_context": {
    "task_number": N,
    "task_name": "{project_name}",
    "description": "{description}",
    "task_type": "{task_type}"
  },
  "artifact_number": "{artifact_number from Stage 3a}",
  "effort_flag": "{effort_flag from command, null if not set}",
  "model_flag": "{model_flag from command, null if not set}",
  "roadmap_flag": "{roadmap_flag from command, false if not set}",
  "research_path": "{path to research report if exists}",
  "prior_plan_path": "{path to latest prior plan if exists}",
  "roadmap_path": "specs/ROADMAP.md",
  "metadata_file_path": "specs/{NNN}_{SLUG}/.return-meta.json"
}

Note: The artifact_number field tells the agent which sequence number to use for artifact naming (e.g., 01, 02). Plan uses (next_artifact_number - 1) to share the same round as the preceding research.

Model/Effort Flags: If model_flag is set (haiku, sonnet, opus), pass it as the model parameter on the Task tool to override the agent's frontmatter default. If effort_flag is set (fast, hard), include it as prompt context for reasoning depth guidance.

Stage 4b: Read and Inject Format Specification

Read the plan format file and prepare it for injection into the subagent prompt. This ensures the subagent always has the full format specification in its context, regardless of whether it reads the file itself.

format_content=$(cat .claude/context/formats/plan-format.md)

The format content will be included as a delimited section in the Stage 5 prompt (see below).

Stage 5: Invoke Subagent

CRITICAL: You MUST use the Task tool to spawn the subagent.

Required Tool Invocation:

Tool: Task (NOT Skill)
Parameters:
  - subagent_type: "planner-agent"
  - prompt: [Include task_context, delegation_context, research_path, metadata_file_path,
             AND the format specification from Stage 4b as shown below]
  - description: "Execute planning for task {N}"

Format Injection: Include the format specification from Stage 4b in the prompt as a clearly-delimited section:

<artifact-format-specification>
## CRITICAL: Plan Format Requirements

You MUST follow this format specification exactly when writing the plan artifact.
Non-compliance will be caught by postflight validation.

{format_content from Stage 4b}
</artifact-format-specification>

Place this section AFTER the delegation context JSON and BEFORE any other instructions.

Memory Context Injection: If memory_context from Stage 4a is non-empty, include it in the prompt as a separate block:

{memory_context from Stage 4a -- already wrapped in <memory-context> tags}

Place the memory context block AFTER the format specification and BEFORE the task-specific instructions. Do NOT inject an empty <memory-context> block when no memories were retrieved.

DO NOT use Skill(planner-agent) - this will FAIL.

The subagent will:

Load planning context files
Analyze task requirements and research
Decompose into logical phases
Identify risks and mitigations
Create plan in specs/{NNN}_{SLUG}/plans/
Write metadata to specs/{NNN}_{SLUG}/.return-meta.json
Return a brief text summary (NOT JSON)

Stage 5b: Self-Execution Fallback

CRITICAL: If you performed the work above WITHOUT using the Task tool (i.e., you read files, wrote artifacts, or updated metadata directly instead of spawning a subagent), you MUST write a .return-meta.json file now before proceeding to postflight. Use the schema from return-metadata-file.md with status value "planned" and the appropriate artifact information.

If you DID use the Task tool (Stage 5), skip this stage -- the subagent already wrote the metadata.

Postflight (ALWAYS EXECUTE)

The following stages MUST execute after work is complete, whether the work was done by a subagent (Stage 5) or inline (Stage 5b). Do NOT skip these stages for any reason.

Stage 6: Parse Subagent Return (Read Metadata File)

Read the metadata file:

metadata_file="specs/${padded_num}_${project_name}/.return-meta.json"

if [ -f "$metadata_file" ] && jq empty "$metadata_file" 2>/dev/null; then
    status=$(jq -r '.status' "$metadata_file")
    artifact_path=$(jq -r '.artifacts[0].path // ""' "$metadata_file")
    artifact_type=$(jq -r '.artifacts[0].type // ""' "$metadata_file")
    artifact_summary=$(jq -r '.artifacts[0].summary // ""' "$metadata_file")
else
    echo "Error: Invalid or missing metadata file"
    status="failed"
fi

Stage 6a: Validate Artifact Content

If subagent status is "planned" and artifact_path is non-empty, validate the plan artifact against format requirements. This is non-blocking -- warnings are logged but do not prevent postflight from completing.

if [ "$status" = "planned" ] && [ -n "$artifact_path" ] && [ -f "$artifact_path" ]; then
    echo "Validating plan artifact..."
    if ! bash .claude/scripts/validate-artifact.sh "$artifact_path" plan --fix; then
        echo "WARNING: Plan artifact has format issues (non-blocking). Review output above."
    fi
fi

Note: The --fix flag attempts auto-repair of missing metadata fields. Validation failures are logged but do not block status update or git commit.

Stage 7: Update Task Status (Postflight)

If subagent status is "planned", update state.json and TODO.md atomically using the centralized script:

bash .claude/scripts/update-task-status.sh postflight $task_number plan $session_id

If the script exits non-zero, log a warning but continue with artifact linking and git commit (postflight errors are non-blocking).

On partial/failed: Keep status as "planning" for resume (do not call the script).

Stage 8: Link Artifacts

Add artifact to state.json with summary.

IMPORTANT: Use two-step jq pattern to avoid Issue #1132 escaping bug. See jq-escaping-workarounds.md.

if [ -n "$artifact_path" ]; then
    # Step 1: Filter out existing plan artifacts (use "| not" pattern to avoid != escaping - Issue #1132)
    jq '(.active_projects[] | select(.project_number == '$task_number')).artifacts =
        [(.active_projects[] | select(.project_number == '$task_number')).artifacts // [] | .[] | select(.type == "plan" | not)]' \
      specs/state.json > specs/tmp/state.json && mv specs/tmp/state.json specs/state.json

    # Step 2: Add new plan artifact
    jq --arg path "$artifact_path" \
       --arg type "$artifact_type" \
       --arg summary "$artifact_summary" \
      '(.active_projects[] | select(.project_number == '$task_number')).artifacts += [{"path": $path, "type": $type, "summary": $summary}]' \
      specs/state.json > specs/tmp/state.json && mv specs/tmp/state.json specs/state.json
fi

Update TODO.md: Link artifact using the automated script:

bash .claude/scripts/link-artifact-todo.sh $task_number '**Plan**' '**Description**' "$artifact_path"

If the script exits non-zero, log a warning but continue (linking errors are non-blocking).

Stage 9: Git Commit

Commit changes with session ID:

git add -A
git commit -m "task ${task_number}: create implementation plan

Session: ${session_id}

Stage 10: Cleanup

Remove marker and metadata files:

rm -f "specs/${padded_num}_${project_name}/.postflight-pending"
rm -f "specs/${padded_num}_${project_name}/.postflight-loop-guard"
rm -f "specs/${padded_num}_${project_name}/.return-meta.json"

Stage 11: Return Brief Summary

Return a brief text summary (NOT JSON). Example:

Plan created for task {N}:
- {phase_count} phases defined, {estimated_hours} hours estimated
- Key phases: {phase names}
- Created plan at specs/{NNN}_{SLUG}/plans/MM_{short-slug}.md
- Status updated to [PLANNED]
- Changes committed

Error Handling

Input Validation Errors

Return immediately with error message if task not found or status invalid.

Metadata File Missing

If subagent didn't write metadata file:

Keep status as "planning"
Do not cleanup postflight marker
Report error to user

Git Commit Failure

Non-blocking: Log failure but continue with success response.

jq Parse Failure

If jq commands fail with INVALID_CHARACTER or syntax error (Issue #1132):

Log to errors.json:

jq --arg ts "$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
   --arg sid "$session_id" \
   --arg msg "jq parse error in postflight artifact linking" \
   --argjson task "$task_number" \
  '.errors += [{
    "id": ("err_" + ($ts | gsub("[^0-9]"; ""))),
    "timestamp": $ts,
    "type": "jq_parse_failure",
    "severity": "medium",
    "message": $msg,
    "context": {"session_id": $sid, "command": "/plan", "task": $task, "checkpoint": "GATE_OUT"},
    "recovery": {"suggested_action": "Use two-step jq pattern from jq-escaping-workarounds.md", "auto_recoverable": true},
    "fix_status": "unfixed"
  }]' specs/errors.json > specs/tmp/errors.json && mv specs/tmp/errors.json specs/errors.json

Retry with two-step pattern (already implemented in Stage 8)

Subagent Timeout

Return partial status if subagent times out (default 1800s). Keep status as "planning" for resume.

MUST NOT (Postflight Boundary)

After the agent returns, this skill MUST NOT:

Edit source files - All planning work is done by agent
Run build/test commands - Verification is done by agent
Use research tools - Web/codebase search is for agent use only
Analyze task requirements - Analysis is agent work
Write plan files - Artifact creation is agent work

The postflight phase is LIMITED TO:

Reading agent metadata file
Updating status via update-task-status.sh (handles state.json + TODO.md atomically)
Linking artifacts in state.json
Git commit
Cleanup of temp/marker files

Reference: @.claude/context/standards/postflight-tool-restrictions.md

Return Format

This skill returns a brief text summary (NOT JSON). The JSON metadata is written to the file and processed internally.

Example successful return:

Plan created for task 414:
- 5 phases defined, 2.5 hours estimated
- Covers: agent structure, execution flow, error handling, examples, verification
- Created plan at specs/414_create_planner_agent/plans/MM_{short-slug}.md
- Status updated to [PLANNED]
- Changes committed with session sess_1736700000_abc123

Example partial return:

Plan partially created for task 414:
- 3 of 5 phases defined before timeout
- Partial plan saved at specs/414_create_planner_agent/plans/MM_{short-slug}.md
- Status remains [PLANNING] - run /plan 414 to complete

skill-planner