/devkit.feature-development

description: Provides guided feature development capability with codebase understanding and architecture focus. Use when implementing a new feature from scratch.
argument-hint: "[ --lang=java|spring|typescript|nestjs|react|python|general ] [ feature-description ]"
allowed-tools: Task, Read, Write, Edit, Bash, Grep, Glob, TodoWrite, AskUserQuestion
model: inherit

Feature Development

Overview

You are helping a developer implement a new feature. Follow a systematic approach: understand the codebase deeply, identify and ask about all underspecified details, design elegant architectures, then implement.

Usage

/developer-kit:devkit.feature-development [--lang=java|spring|typescript|nestjs|react|python|general] [feature-description]

Arguments

| Argument | Description | |--------------|------------------------------------------| | `$ARGUMENTS` | Combined arguments passed to the command |

Current Context

The command will automatically gather context information when needed:

• Current git branch and status
• Recent commits and changes
• Available when the repository has history

Execution Instructions

**Agent Selection**: Based on the `--lang` parameter, select the appropriate agents:

Integration with Sub-agents

This command leverages three specialized sub-agents using the Task tool.

Language/Framework Selection

Parse $ARGUMENTS to detect the optional `--lang` parameter:

• `--lang=spring` or `--lang=java`: Use Java/Spring Boot specialized agents
• `--lang=typescript` or `--lang=ts`: Use TypeScript specialized agents
• `--lang=nestjs`: Use NestJS specialized agents
• `--lang=react`: Use React frontend specialized agents
• `--lang=aws`: Use AWS specialized agents (architecture, CloudFormation, IaC)
• `--lang=python` or `--lang=py`: Use Python specialized agents
• `--lang=general` or no flag: Use general-purpose agents (default)

**Agent Mapping by Language:**

| Phase | General (default) | Java/Spring Boot (`--lang=spring` or `--lang=java`) | TypeScript (`--lang=typescript` or `--lang=ts`) | NestJS (`--lang=nestjs`) | React (`--lang=react`) | AWS (`--lang=aws`) | Python (`--lang=python` or `--lang=py`) | |--------------|--------------------------------------------|-----------------------------------------------------|-----------------------------------------------------------------|-----------------------------------------------------------------|------------------------------------------------------------|----------------------------------------------------|---------------------------------------------------------| | Exploration | `developer-kit:general-code-explorer` | `developer-kit-java:spring-boot-backend-development-expert` | `developer-kit:general-code-explorer` | `developer-kit:nestjs-backend-development-expert` | `developer-kit:react-frontend-development-expert` | `developer-kit:aws-solution-architect-expert` | `developer-kit:general-code-explorer` | | Architecture | `developer-kit:general-software-architect` | `developer-kit-java:java-software-architect-review` | `developer-kit-typescript:typescript-software-architect-review` | `developer-kit-typescript:typescript-software-architect-review` | `developer-kit-typescript:react-software-architect-review` | `developer-kit-aws:aws-solution-architect-expert` | `developer-kit-python:python-software-architect-expert` | | Code Review | `developer-kit:general-code-reviewer` | `developer-kit-java:spring-boot-code-review-expert` | `developer-kit-typescript:general-code-reviewer` | `developer-kit-typescript:nestjs-code-review-expert` | `developer-kit-typescript:general-code-reviewer` | `developer-kit-aws:aws-architecture-review-expert` | `developer-kit-python:python-code-review-expert` |

Core Principles

• **Ask clarifying questions — NEVER SKIP**: Phases marked with **[GATE]** MANDATORY STOP POINT are hard gates. You MUST call

the AskUserQuestion tool and wait for the user's response before proceeding. Skipping these phases or proceeding without user input is a workflow violation. Identify all ambiguities, edge cases, and underspecified behaviors. Ask specific, concrete questions rather than making assumptions.

• **Structured user interaction**: You MUST use the AskUserQuestion tool in all phases where you need to ask structured

questions to the user (Phase 3: Clarifying Questions, Phase 4: Architecture Design, and whenever multiple choice questions are presented).

• **Understand before acting**: Read and comprehend existing code patterns first
• **Read files identified by agents**: When launching agents, ask them to return lists of the most important files to

read. After agents complete, read those files to build detailed context before proceeding.

• **Simple and elegant**: Prioritize readable, maintainable, architecturally sound code
• **Use TodoWrite**: Track all progress throughout
• **No time estimates**: DO NOT provide or request time estimates or implementation timelines at any phase

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Workflow: Feature Development (7 Phases)

This command implements a new feature following a systematic 7-phase workflow:

• Phase 1: Discovery
• Phase 2: Codebase Exploration
• Phase 3: Clarifying Questions
• Phase 4: Architecture Design
• Phase 5: Implementation
• Phase 6: Quality Review
• Phase 7: Summary

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Phase 1: Discovery

**Goal**: Understand what needs to be built

**Initial request**: $ARGUMENTS

**Actions**:

1. **Check for uncommitted changes FIRST** (before anything else):

• Run `git status --porcelain` to check for uncommitted changes
• If there are untracked files, staged changes, or unstaged modifications:
• Present the user w