- name
- skill-spawn
- description
- Research blockers and spawn new tasks to overcome them, updating parent task dependencies
- allowed-tools
- Task, Bash, Edit, Read, Write
# Spawn Skill
Thin wrapper that delegates blocker analysis to `spawn-agent` subagent, then handles all state management in postflight: creates new task entries, establishes parent-child relationships, and updates dependencies.
**IMPORTANT**: This skill implements the skill-internal postflight pattern. After the subagent returns, this skill handles all postflight operations (task creation, dependency linking, git commit) before returning. This eliminates the "continue" prompt issue between skill return and orchestrator.
## Context References
Reference (do not load eagerly):
- Path: `.opencode/context/formats/return-metadata-file.md` - Metadata file schema
- Path: `.opencode/context/patterns/postflight-control.md` - Marker file protocol
- Path: `.opencode/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 not terminal (completed, abandoned, expanded)
- /spawn command is invoked with a valid task number
---
## Execution Flow
### Stage 1: Parse Delegation Context
Parse inputs from the /spawn command:
```bash
# Extract from delegation context
task_number=$1
session_id="$2"
blocker_prompt="$3" # May be empty
# Lookup task data
task_data=$(jq -r --argjson num "$task_number" \
'.active_projects[] | select(.project_number == $num)' \
specs/state.json)
# Validate exists
if [ -z "$task_data" ]; then
echo "Error: Task $task_number not found"
exit 1
fi
# Extract fields
project_name=$(echo "$task_data" | jq -r '.project_name')
task_type=$(echo "$task_data" | jq -r '.task_type // "general"')
status=$(echo "$task_data" | jq -r '.status')
description=$(echo "$task_data" | jq -r '.description // ""')
```
---
### Stage 2: Preflight Status Update
Update parent task status to "blocked" BEFORE invoking subagent.
**Update state.json**:
```bash
padded_num=$(printf "%03d" "$task_number")
jq --arg ts "$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
--arg status "blocked" \
--arg sid "$session_id" \
'(.active_projects[] | select(.project_number == '$task_number')) |= . + {
status: $status,
last_updated: $ts,
session_id: $sid
}' specs/state.json > specs/tmp/state.json && mv specs/tmp/state.json specs/state.json
```
---
### Stage 3: Update TODO.md Parent Status
Use Edit tool to change status marker to `[BLOCKED]` if not already blocked.
```markdown
old_string: - **Status**: [{current_status}]
new_string: - **Status**: [BLOCKED]
```
---
### Stage 4: Create Postflight Marker
Create the marker file to prevent premature termination:
```bash
mkdir -p "specs/${padded_num}_${project_name}"
cat > "specs/${padded_num}_${project_name}/.postflight-pending" << EOF
{
"session_id": "${session_id}",
"skill": "skill-spawn",
"task_number": ${task_number},
"operation": "spawn",
"reason": "Postflight pending: task creation, dependency linking, git commit",
"created": "$(date -u +%Y-%m-%dT%H:%M:%SZ)",
"stop_hook_active": false
}
EOF
```
---
### Stage 5: Prepare Delegation Context
Find the latest plan path (if exists):
```bash
plan_path=""
if [ -d "specs/${padded_num}_${project_name}/plans" ]; then
plan_path=$(ls -t "specs/${padded_num}_${project_name}/plans/"*.md 2>/dev/null | head -1)
fi
```
Prepare delegation context for the subagent:
```json
{
"session_id": "sess_{timestamp}_{random}",
"delegation_depth": 2,
"delegation_path": ["orchestrator", "spawn", "skill-spawn"],
"timeout": 1800,
"task_number": N,
"task_data": {
"project_number": N,
"project_name": "{slug}",
"status": "blocked",
"task_type": "{task_type}",
"description": "{description}",
"effort": "{effort}"
},
"blocker_prompt": "{optional user description}",
"plan_path": "{path to latest plan or null}",
"metadata_file_path": "specs/{NNN}_{SLUG}/.return-meta.json"
}
```
---
### Stage 6: Invoke Subagent
**CRITICAL**: You MUST use the **Task** tool to spawn the subagent.
**Required Tool Invocation**:
```
Tool: Task (NOT Skill)
Parameters:
- subagent_type: "spawn-agent"
- prompt: [Include task_number, task_data, blocker_prompt, plan_path, metadata_file_path, session_id]
- description: "Analyze blocker for task {N} and propose new tasks"
```
**DO NOT** use `Skill(spawn-agent)` - this will FAIL.
The subagent will:
- Load task context and plan
- Analyze the blocker and identify root cause
- Propose minimal new tasks with dependencies
- Write blocker analysis report
- Write `.spawn-return.json` with task definitions
- Return a brief text summary (NOT JSON)
---
### Stage 6b: 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 the appropriate status value for this operation.
If you DID use the Task tool, 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 or inline (Stage 6b). Do NOT skip these stages for any reason.
### Stage 7: Read Return Metadata
Read the spawn return file:
```bash
spawn_file="specs/${padded_num}_${project_name}/.spawn-return.json"
if [ -f "$spawn_file" ] && jq empty "$spawn_file" 2>/dev/null; then
new_tasks=$(jq -r '.new_tasks' "$spawn_file")
dependency_order=$(jq -r '.dependency_order' "$spawn_file")
analysis_summary=$(jq -r '.analysis_summary' "$spawn_file")
report_path=$(jq -r '.report_path' "$spawn_file")
task_count=$(jq '.new_tasks | length' "$spawn_file")
else
echo "Error: Invalid or missing spawn return file"
exit 1
fi
```
---
### Stage 8: Get Next Task Numbers
Get the next available task numbers from state.json:
```bash
next_num=$(jq -r '.next_project_number' specs/state.json)
# Calculate task numbers for each new task based on dependency_order
# First task gets next_num, second gets next_num+1, etc.
```
---
### Stage 9: Apply Topological Sort (Kahn's Algorithm)
The agent provides `dependency_order` which is already topologically sorted (foundational tasks first). Map internal indices to actual task numbers:
```bash
# Example: dependency_order = [0, 1] means task at index 0 is foundational
# If next_num = 242:
# - Index 0 -> Task {N} (foundational)
# - Index 1 -> Task {M} (depends on {N})
# Build index->task_number mapping
declare -A task_num_map
order_idx=0
for idx in $(echo "$dependency_order" | jq -r '.[]'); do
task_num_map[$idx]=$((next_num + order_idx))
order_idx=$((order_idx + 1))
done
```
---
### Stage 10: Create New Task Directories
For each new task, create directory structure:
```bash
for idx in $(echo "$dependency_order" | jq -r '.[]'); do
new_task_num=${task_num_map[$idx]}
new_padded=$(printf "%03d" "$new_task_num")
# Get task data from spawn return
task_title=$(jq -r --argjson i "$idx" '.new_tasks[$i].title' "$spawn_file")
task_slug=$(echo "$task_title" | tr '[:upper:]' '[:lower:]' | tr ' ' '_' | sed 's/[^a-z0-9_]//g')
# Create directory with research artifact stub
mkdir -p "specs/${new_padded}_${task_slug}/reports"
# Copy spawn analysis as initial research for first task
# (or create stub pointing to parent's spawn analysis)
done
```
---
### Stage 11: Update state.json with New Tasks
Insert new tasks in topological order (foundational first):
```bash
for idx in $(echo "$dependency_order" | jq -r '.[]'); do
new_task_num=${task_num_map[$idx]}
# Extract task fields
task_title=$(jq -r --argjson i "$idx" '.new_tasks[$i].title' "$spawn_file")
task_desc=$(jq -r --argjson i "$idx" '.new_tasks[$i].description' "$spawn_file")
task_effort=$(jq -r --argjson i "$idx" '.new_tasks[$i].effort' "$spawn_file")
task_lang=$(jq -r --argjson i "$idx" '.new_tasks[$i].task_type' "$spawn_file")
internal_deps=$(jq -r --argjson i "$idx" '.new_tasks[$i].dependencies' "$spawn_file")
# Convert internal deps to task numbers
resolved_deps="[]"
for dep_idx in $(echo "$internal_deps" | jq -r '.[]'); do
dep_num=${task_num_map[$dep_idx]}
resolved_deps=$(echo "$resolved_deps" | jq --argjson n "$dep_num" '. + [$n]')
done
# Create task slug
task_slug=$(echo "$task_title" | tr '[:upper:]' '[:lower:]' | tr ' ' '_' | sed 's/[^a-z0-9_]//g')
# Add to state.json
jq --arg ts "$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
--argjson num "$new_task_num" \
--arg name "$task_slug" \
--arg desc "$task_desc" \
--arg effort "$task_effort" \
--arg lang "$task_lang" \
--argjson deps "$resolved_deps" \
--argjson parent "$task_number" \
--arg report "$report_path" \
'.active_projects += [{
"project_number": $num,
"project_name": $name,
"status": "researched",
"task_type": $lang,
"description": $desc,
"effort": $effort,
"parent_task": $parent,
"dependencies": $deps,
"created": $ts,
"last_updated": $ts,
"artifacts": [{"type": "research", "path": $report, "summary": "Spawn analysis from parent task"}]
}]' specs/state.json > specs/tmp/state.json && mv specs/tmp/state.json specs/state.json
done
# Update next_project_number
jq --argjson next "$((next_num + task_count))" \
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