rn-feature-dev

A guided eight-phase process for building and checking a feature in a React Native app, a framework for mobile apps. It covers codebase exploration, architecture, implementation, device verification, review, and end-to-end proof.

In plain words
What is it for?
Use it when adding a screen or other feature to a React Native app and you want structured exploration, implementation, live device testing, quality review, and proof artifacts.
Why use it?
It provides a fixed sequence for feature work, including approval of the design and evidence that each verification step passed. This helps prevent important discovery, review, or testing work from being skipped.

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/lykhoyda/rn-dev-agent/rn-feature-dev
Clone the repo
git clone --depth 1 https://github.com/Lykhoyda/rn-dev-agent
Per session 26 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 271 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 $0.00026 $0.00271
Opus 5 $0.00013 $0.00135
Sonnet 5 $0.00005 $0.00054
Haiku 4.5 $0.00003 $0.00027

Measured 2d ago against content hash cb889ea53077, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

rn-feature-dev 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.

packages/claude-plugin/commands/rn-feature-dev.md · 28 lines

What it actually says

React Native Feature Development

Initial request: $ARGUMENTS

Invoke the rn-feature-development skill and execute the full 8-phase pipeline against the user's feature request above.

The skill contains the complete process:

  • Phase 1 (Discovery) through Phase 8 (E2E Proof)
  • Core principles, safety constraints, and recovery procedures
  • Common Rationalizations, Red Flags, Boundaries, Verification gates

Do not improvise the process. Follow every phase in the skill. Create a todo list at Phase 1 with all 9 phases (1, 2, 3, 4, 5, 5.5, 6, 7, 8) and mark each complete as you progress.

Critical reminders:

  • NEVER skip phases — speed comes from parallel agents, not phase elimination
  • Gate Phase 5 on explicit user approval of the architecture (from Phase 4)
  • Phase 5.5 verification table MUST have concrete Evidence in every row
  • Phase 8 executes the architect's E2E Proof Flow mechanically, step by step
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 · 28 lines · 26 tokens per session scan A cb889ea53077

Subscribe to this mod's changes

rn-feature-dev is a command published in the GitHub repository Lykhoyda/rn-dev-agent (11 stars, last pushed 2d ago), licensed MIT. It adds 26 tokens to every session and 271 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.