feature-development

A step-by-step feature-development process that takes a software change from requirements through deployment.

In plain words
What is it for?
It is for planning and implementing features, recording each phase in .feature-dev/, running checks, requesting approval, and preparing changes for deployment.
Why use it?
It keeps work ordered and reviewable by requiring output files, approval checkpoints, and an immediate stop when a step fails.

Command

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/wshobson/agents/feature-development
Clone the repo
git clone --depth 1 https://github.com/wshobson/agents
Per session 12 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,535 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00012 $0.03535
Opus 5 $0.00006 $0.01767
Sonnet 5 $0.00002 $0.00707
Haiku 4.5 $0.00001 $0.00353

Measured 2d ago against content hash 0a3315c4c555, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

feature-development scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/backend-development/commands/feature-development.md · 482 lines

How it starts

The opening of the file, as written. The whole thing — 482 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Feature Development Orchestrator

CRITICAL BEHAVIORAL RULES

You MUST follow these rules exactly. Violating any of them is a failure.

  1. Execute steps in order. Do NOT skip ahead, reorder, or merge steps.
  2. Write output files. Each step MUST produce its output file in .feature-dev/ before the next step begins. Read from prior step files — do NOT rely on context window memory.
  3. Stop at checkpoints. When you reach a PHASE CHECKPOINT, you MUST stop and wait for explicit user approval before continuing. Use the AskUserQuestion tool with clear options.
  4. Halt on failure. If any step fails (agent error, test failure, missing dependency), STOP immediately. Present the error and ask the user how to proceed. Do NOT silently continue.
  5. Use only local agents. All subagent_type references use agents bundled with this plugin or general-purpose. No cross-plugin dependencies.
  6. Never enter plan mode autonomously. Do NOT use EnterPlanMode. This command IS the plan — execute it.

Pre-flight Checks

Before starting, perform these checks:

1. Check for existing session

Check if .feature-dev/state.json exists:

  • If it exists and status is "in_progress": Read it, display the current step, and ask the user:

    Found an in-progress feature development session:
    Feature: [name from state]
    Current step: [step from state]
    
    1. Resume from where we left off
    2. Start fresh (archives existing session)
    
  • If it exists and status is "complete": Ask whether to archive and start fresh.

2. Initialize state

Create .feature-dev/ directory and state.json:

{
  "feature": "$ARGUMENTS",
  "status": "in_progress",
  "methodology": "traditional",
  "complexity": "medium",
  "current_step": 1,
  "current_phase": 1,
  "completed_steps": [],
  "files_created": [],
  "started_at": "ISO_TIMESTAMP",
  "last_updated": "ISO_TIMESTAMP"
}

Parse $ARGUMENTS for --methodology and --complexity flags. Use defaults if not specified.

Read the full file on GitHub · 482 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 482 lines · 12 tokens per session scan A 0a3315c4c555

Subscribe to this mod's changes

feature-development is a command published in the GitHub repository wshobson/agents (39,318 stars, last pushed yesterday), licensed MIT. It adds 12 tokens to every session and 3,535 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.