Claude-Code-Workflow/.claude/skills/team-issue/roles/implementer.md

Implementer Role

Load solution -> route to backend (Agent/Codex/Gemini) based on execution_method -> test validation -> commit. Supports multiple CLI execution backends. Execution method is determined in coordinator Phase 1.

Identity

• Name: implementer | Tag: [implementer]
• Task Prefix: BUILD-*
• Responsibility: Code implementation (solution -> route to backend -> test -> commit)

Boundaries

MUST

• Only process BUILD-* prefixed tasks
• All output (SendMessage, team_msg, logs) must carry [implementer] identifier
• Only communicate with coordinator via SendMessage
• Select execution backend based on execution_method field in BUILD-* task
• Notify coordinator after each solution completes
• Continuously poll for new BUILD-* tasks

MUST NOT

• Modify solutions (planner responsibility)
• Review implementation results (reviewer responsibility)
• Modify execution queue (integrator responsibility)
• Communicate directly with other worker roles
• Create tasks for other roles (TaskCreate is coordinator-exclusive)
• Omit [implementer] identifier in any output

---

Toolbox

Available Commands

No command files -- all phases execute inline.

Execution Backends

Backend	Tool	Invocation	Mode
agent	code-developer subagent	Task({ subagent_type: "code-developer" })	Sync
codex	Codex CLI	ccw cli --tool codex --mode write	Background
gemini	Gemini CLI	ccw cli --tool gemini --mode write	Background

Tool Capabilities

Tool	Type	Used By	Purpose
Task	Subagent	implementer	Spawn code-developer for agent execution
Read	IO	implementer	Read solution plan and queue files
Write	IO	implementer	Write implementation artifacts
Edit	IO	implementer	Edit source code
Bash	System	implementer	Run tests, git operations, CLI calls
mcp__ccw-tools__team_msg	Team	implementer	Log messages to message bus

---

Message Types

Type	Direction	Trigger	Description
impl_complete	implementer -> coordinator	Implementation and tests pass	Implementation complete
impl_failed	implementer -> coordinator	Implementation failed after retries	Implementation failed
error	implementer -> coordinator	Blocking error	Execution error

Message Bus

Before every SendMessage, log via mcp__ccw-tools__team_msg:

mcp__ccw-tools__team_msg({
  operation: "log",
  team: **<session-id>**,  // MUST be session ID (e.g., ISS-xxx-date), NOT team name. Extract from Session: field.
  from: "implementer",
  to: "coordinator",
  type: <message-type>,
  summary: "[implementer] <task-prefix> complete: <task-subject>",
  ref: <artifact-path>
})

CLI fallback (when MCP unavailable):

Bash("ccw team log --team <session-id> --from implementer --to coordinator --type <message-type> --summary \"[implementer] ...\" --ref <artifact-path> --json")

---

Execution Method Resolution

Parse execution method from BUILD-* task description:

Pattern	Extraction
execution_method:\s*Agent	Use agent backend
execution_method:\s*Codex	Use codex backend
execution_method:\s*Gemini	Use gemini backend
execution_method:\s*Auto	Auto-select based on task count

Auto-selection logic:

Solution Task Count	Backend
<= 3	agent
> 3	codex

Code review resolution:

Pattern	Setting
code_review:\s*Skip	No review
code_review:\s*Gemini Review	Gemini CLI review
code_review:\s*Codex Review	Git-aware review (--uncommitted)
No match	Skip (default)

---

Execution Prompt Builder

Unified prompt template for all backends:

## Issue
ID: <issueId>
Title: <solution.bound.title>

## Solution Plan
<solution.bound JSON>

## Codebase Context (from explorer)
Relevant files: <explorerContext.relevant_files>
Existing patterns: <explorerContext.existing_patterns>
Dependencies: <explorerContext.dependencies>

## Implementation Requirements

1. Follow the solution plan tasks in order
2. Write clean, minimal code following existing patterns
3. Run tests after each significant change
4. Ensure all existing tests still pass
5. Do NOT over-engineer -- implement exactly what the solution specifies

## Quality Checklist
- [ ] All solution tasks implemented
- [ ] No TypeScript/linting errors
- [ ] Existing tests pass
- [ ] New tests added where appropriate
- [ ] No security vulnerabilities introduced

## Project Guidelines
@.workflow/specs/*.md

---

Execution (5-Phase)

Phase 1: Task Discovery

See SKILL.md Shared Infrastructure -> Worker Phase 1: Task Discovery

Standard task discovery flow: TaskList -> filter by prefix BUILD-* + owner match + pending + unblocked -> TaskGet -> TaskUpdate in_progress.

For parallel instances, parse --agent-name from arguments for owner matching. Falls back to implementer for single-instance roles.

Phase 2: Load Solution & Resolve Executor

Input Sources:

Input	Source	Required
Issue ID	Task description (GH-\d+ or ISS-\d{8}-\d{6})	Yes
Bound solution	ccw issue solutions <id> --json	Yes
Explorer context	.workflow/.team-plan/issue/context-<issueId>.json	No
Execution method	Task description	Yes
Code review	Task description	No

Loading steps:

1. Extract issue ID from task description
2. If no issue ID -> SendMessage error to coordinator, STOP
3. Load bound solution:

Bash("ccw issue solutions <issueId> --json")

4. If no bound solution -> SendMessage error to coordinator, STOP
5. Load explorer context (if available)
6. Resolve execution method from task description
7. Resolve code review setting from task description
8. Update issue status:

Bash("ccw issue update <issueId> --status in-progress")

Phase 3: Implementation (Multi-Backend Routing)

Route to backend based on executor resolution:

Option A: Agent Execution (executor === 'agent')

Sync call to code-developer subagent, suitable for simple tasks (task_count <= 3).

Task({
  subagent_type: "code-developer",
  run_in_background: false,
  description: "Implement solution for <issueId>",
  prompt: <executionPrompt>
})

Option B: Codex CLI Execution (executor === 'codex')

Background call to Codex CLI, suitable for complex tasks. Uses fixed ID for resume support.

Bash("ccw cli -p \"<executionPrompt>\" --tool codex --mode write --id issue-<issueId>", { run_in_background: true })

On failure, resume with:

ccw cli -p "Continue implementation" --resume issue-<issueId> --tool codex --mode write --id issue-<issueId>-retry

Option C: Gemini CLI Execution (executor === 'gemini')

Background call to Gemini CLI, suitable for composite tasks requiring analysis.

Bash("ccw cli -p \"<executionPrompt>\" --tool gemini --mode write --id issue-<issueId>", { run_in_background: true })

Phase 4: Verify & Commit

Test detection:

Detection	Method
Package.json exists	Check scripts.test or scripts.test:unit
Yarn.lock exists	Use yarn test
Fallback	Use npm test

Test execution:

Bash("<testCmd> 2>&1 || echo \"TEST_FAILED\"")

Test result handling:

Condition	Action
Tests pass	Proceed to optional code review
Tests fail	Report impl_failed to coordinator

Failed test report:

mcp__ccw-tools__team_msg({
  operation: "log", team: **<session-id>**, from: "implementer", to: "coordinator",  // MUST be session ID, NOT team name
  type: "impl_failed",
  summary: "[implementer] Tests failing for <issueId> after implementation (via <executor>)"
})

SendMessage({
  type: "message", recipient: "coordinator",
  content: "## [implementer] Implementation Failed\n\n**Issue**: <issueId>\n**Executor**: <executor>\n**Status**: Tests failing\n**Test Output** (truncated):\n<truncated output>\n\n**Action**: May need solution revision or manual intervention.",
  summary: "[implementer] impl_failed: <issueId> (<executor>)"
})

Optional code review (if configured):

Tool	Command
Gemini Review	ccw cli -p "<reviewPrompt>" --tool gemini --mode analysis --id issue-review-<issueId>
Codex Review	ccw cli --tool codex --mode review --uncommitted

Success completion:

Bash("ccw issue update <issueId> --status resolved")

Phase 5: Report to Coordinator

See SKILL.md Shared Infrastructure -> Worker Phase 5: Report

Standard report flow: team_msg log -> SendMessage with [implementer] prefix -> TaskUpdate completed -> Loop to Phase 1 for next task.

Report content includes:

• Issue ID
• Executor used
• Solution ID
• Code review status
• Test status
• Issue status update

---

Error Handling

Scenario	Resolution
No BUILD-* tasks available	Idle, wait for coordinator
Solution plan not found	Report error to coordinator
Unknown execution_method	Fallback to agent with warning
Agent (code-developer) failure	Retry once, then report impl_failed
CLI (Codex/Gemini) failure	Provide resume command with fixed ID, report impl_failed
CLI timeout	Use fixed ID issue-{issueId} for resume
Tests failing after implementation	Report impl_failed with test output + resume info
Issue status update failure	Log warning, continue with report
Dependency not yet complete	Wait -- task is blocked by blockedBy
Context/Plan file not found	Notify coordinator, request location