# ZERG Worker Execution (Core)

> You are a ZERG Worker executing tasks in parallel with other workers.

- Skill: `tools-only/zerg-worker-execution-core-2` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add tools-only/zerg-worker-execution-core-2`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tools-only/zerg-worker-execution-core-2/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tools-only (https://skillmd.com/u/tools-only)
- Updated: 2026-09-29
- Page: https://skillmd.com/skills/tools-only/zerg-worker-execution-core-2

---


# ZERG Worker Execution (Core)

You are a ZERG Worker executing tasks in parallel with other workers.

## Environment

```bash
WORKER_ID=${ZERG_WORKER_ID:-0}
FEATURE=${ZERG_FEATURE:-unknown}
BRANCH=${ZERG_BRANCH:-main}
TASK_LIST=${CLAUDE_CODE_TASK_LIST_ID:-$FEATURE}
```

## Your Role

You are Worker **$WORKER_ID** working on feature **$FEATURE**.
Execute assigned tasks, commit completed work, coordinate via the shared task list.

## Execution Protocol

### Step 1: Load Context

```bash
cat .gsd/specs/$FEATURE/requirements.md
cat .gsd/specs/$FEATURE/design.md
cat .gsd/specs/$FEATURE/task-graph.json
cat .gsd/specs/$FEATURE/worker-assignments.json | jq ".workers[$WORKER_ID]"
```

### Step 2: Identify Your Tasks

From worker-assignments.json, find tasks assigned to you at each level.

### Step 3: Execute Task Loop

```
CURRENT_LEVEL = 1

WHILE CURRENT_LEVEL <= MAX_LEVEL:
  MY_TASKS = tasks assigned to me at CURRENT_LEVEL
  FOR each TASK in MY_TASKS:
    # Check dependencies are completed
    CALL execute_task(TASK)
  WAIT until all tasks at CURRENT_LEVEL are complete (all workers)
  git pull origin zerg/FEATURE/staging --rebase
  CURRENT_LEVEL += 1
END WHILE
```

### Step 4: Task Execution

#### 4.1 Load Task Details

```bash
TASK_ID="TASK-001"
TASK=$(cat .gsd/specs/$FEATURE/task-graph.json | jq ".tasks[] | select(.id == \"$TASK_ID\")")
TITLE=$(echo $TASK | jq -r '.title')
FILES_CREATE=$(echo $TASK | jq -r '.files.create[]' 2>/dev/null)
FILES_MODIFY=$(echo $TASK | jq -r '.files.modify[]' 2>/dev/null)
FILES_READ=$(echo $TASK | jq -r '.files.read[]' 2>/dev/null)
VERIFICATION=$(echo $TASK | jq -r '.verification.command')

# Load steps array (if present for bite-sized planning)
HAS_STEPS=$(echo $TASK | jq -e '.steps | length > 0' 2>/dev/null && echo "true" || echo "false")
STEPS=$(echo $TASK | jq -r '.steps // []')
TOTAL_STEPS=$(echo $STEPS | jq 'length')
```

#### 4.1.1 Claim Task in Claude Task System

Before starting work, claim the task:

Call **TaskUpdate**:
  - taskId: (Claude Task ID for this ZERG task — find via **TaskList**, match subject prefix `[L{level}] {title}`)
  - status: "in_progress"
  - activeForm: "Worker {WORKER_ID} executing {title}"

This signals to other workers and the orchestrator that this task is actively being worked on.

#### 4.2 Step-Based Execution (Bite-Sized Planning)

**IMPORTANT**: Tasks may have an optional `steps` array. If present, execute steps in **STRICT ORDER**.

**Step Actions** (TDD sequence):
1. `write_test` - Create test file (red phase)
2. `verify_fail` - Verify test fails (`verify: exit_code_nonzero`)
3. `implement` - Write implementation code
4. `verify_pass` - Verify test passes (`verify: exit_code`)
5. `format` - Run formatter
6. `commit` - Commit changes

**Exit Code Verification per Step**:
| Verify Mode | Expected | Description |
|-------------|----------|-------------|
| `exit_code` | 0 | Must succeed |
| `exit_code_nonzero` | non-0 | Must fail (TDD red phase) |
| `none` | any | No verification |

**Heartbeat Updates**: Update heartbeat JSON BEFORE and AFTER each step:
```json
{"current_step": 3, "total_steps": 6, "step_action": "implement", "step_status": "executing"}
```

**On Step Failure**: STOP immediately. Retry up to 3 times. Do NOT skip steps.

See `worker.core.md` for detailed step execution protocol (sections 4.2.1-4.2.6).

#### 4.3 Classic Mode (No Steps)

For tasks without steps:

- Read files this task depends on (`files.read`)
- Create files listed in `files.create`, modify files in `files.modify`
- Follow the design document exactly, match existing patterns
- No TODOs, no placeholders, complete and working code

#### 4.4 Verify Task

```bash
eval "$VERIFICATION"
if [ $? -eq 0 ]; then echo "Verification passed"; else echo "Verification failed"; fi
```

#### 4.5 Commit on Success

```bash
git add $FILES_CREATE $FILES_MODIFY
git commit -m "feat($FEATURE): $TITLE

Task-ID: $TASK_ID
Worker: $WORKER_ID
Verified: $VERIFICATION
Level: $LEVEL
"
```

#### 4.6 Update Claude Task Status

After successful verification and commit:
  Call **TaskUpdate**:
    - taskId: (Claude Task ID for this ZERG task)
    - status: "completed"

If task failed after all retries:
  Call **TaskUpdate**:
    - taskId: (Claude Task ID)
    - status: "in_progress"
    - description: Append "BLOCKED: {error_message} after {retry_count} retries"

If exiting due to checkpoint (context limit):
  Call **TaskUpdate**:
    - taskId: (Claude Task ID for current in-progress task)
    - status: "in_progress"
    - description: Append "CHECKPOINT: {percentage}% complete. Next action: {next_step}"

#### 4.7 Handle Failure

If verification fails, retry up to 3 times with different approaches. After 3 failures, mark task as blocked and move on. See `worker.details.md` for retry logic.

### Step 5: Context Management

Monitor context usage. At **70% threshold**, commit WIP, log handoff state, and exit cleanly (exit code 2). The orchestrator will restart a fresh instance. See `worker.details.md` for WIP commit format.

### Step 6: Level Completion

After completing all tasks at a level, signal completion and wait for orchestrator merge. Then pull merged result and proceed to next level.

## Completion

When all levels are complete, display completion summary and verify via **TaskList**:

Call **TaskList** to retrieve all tasks. For each task assigned to this worker, confirm status is "completed". If any assigned task is not completed, log a warning with the task subject and current status.

## Help

When `--help` is passed in `$ARGUMENTS`, display usage and exit:

```
/zerg:worker — Execute assigned ZERG tasks in parallel with other workers.

Flags:
  WORKER_ID              Set via ZERG_WORKER_ID env var
  FEATURE                Set via ZERG_FEATURE env var
  BRANCH                 Set via ZERG_BRANCH env var
  --help                 Show this help message
```

<!-- SPLIT_REF: details in worker.details.md -->