feature-builder

feature-builder is a skill for Claude Code, Codex from TalissonVitorino/kmp-ios-skills. It costs 78 tokens per session (1,234 once invoked), scanned A, original, MIT.

A step-by-step workflow for taking a substantial Android, iOS, or Kotlin Multiplatform feature from planning through implementation, testing, review, and verification.

In plain words
What is it for?
Use it to break down features, build them by layer, run unit, UI, and end-to-end tests, fix build failures, and review the result.
Why use it?
It provides an ordered path for coordinating the many tasks involved in a non-trivial mobile feature. It also helps catch build and test problems before the work is considered complete.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents.

Good fit Use it to break down features, build them by layer, run unit, UI, and end-to-end tests, fix build failures, and review the result.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/talissonvitorino/kmp-ios-skills/feature-builder
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.

Any agent
npx skills add TalissonVitorino/kmp-ios-skills --skill feature-builder
Clone the repo
git clone --depth 1 https://github.com/TalissonVitorino/kmp-ios-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for feature-builder

README.md
[![agentmods](https://agentmods.dev/badge/skills/talissonvitorino/kmp-ios-skills/feature-builder/github.svg)](https://agentmods.dev/skills/talissonvitorino/kmp-ios-skills/feature-builder)
Your own site
<a href="https://agentmods.dev/skills/talissonvitorino/kmp-ios-skills/feature-builder"><img src="https://agentmods.dev/badge/skills/talissonvitorino/kmp-ios-skills/feature-builder/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for feature-builder

Your own site · 80×15
<a href="https://agentmods.dev/skills/talissonvitorino/kmp-ios-skills/feature-builder"><img src="https://agentmods.dev/badge/skills/talissonvitorino/kmp-ios-skills/feature-builder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 78 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,234 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00078 $0.01234
Opus 5 $0.00039 $0.00617
Sonnet 5 $0.00016 $0.00247
Haiku 4.5 $0.00008 $0.00123

Measured 9d ago against content hash c6b53bec7c3b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

feature-builder 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 9d 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.

workflow/feature-builder/SKILL.md · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Feature Builder (workflow)

A structured 6-phase path for building a mobile feature end to end. This is a workflow guide — it sequences the real skills/agents you already have; it does not call external /feature-* pipeline commands.

Platform auto-detect: shared/src/commonMain/KMP · *.xcodeproj / *.xcworkspaceiOS · a module build.gradle(.kts) applying com.android.applicationAndroid. Ambiguous → ask.

The six phases

# Phase Do it with
1 Plan superpowers:brainstormingsuperpowers:writing-plans (or the Plan agent). Output: module breakdown, file list, task order.
2 Implement (by layer) Build in dependency order, pulling the matching library skill per layer (below). Drive with superpowers:test-driven-development.
3 Test Unit + UI + E2E. mobile-testing (Android/JVM) · ios-testing (iOS) · depth: android-skills:android-testing.
4 Build & fix Compile + run tests, fix in a loop (cap ~5 iterations, then escalate). Debug via android-skills:android-debugging.
5 Review superpowers:requesting-code-review, or the feature-dev:code-reviewer / pr-review-toolkit agents. Block on security & correctness.
6 Verify Run the tests for real, confirm coverage/behaviour, re-run to catch flakiness. superpowers:verification-before-completion.

Phase 2 — implementation order (layer by layer)

domain  →  (network ∥ ui)  →  data  →  wiring
  • domain — models, repository interfaces, use cases returning a typed result (error-handling-result).
  • network — API + DTOs (kmp-networking / ktor-patterns). ui — screens, ViewModels, state (jetpack-compose, swiftui-patterns, swiftui-observation, mvi-architecture). No mutual dependency → do them together.
  • data — repository impl, mappers, local cache (kmp-repositories, sqldelight-patterns / room-patterns / swiftdata).
  • wiring — DI (kmp-di / android-di-koin), navigation (navigation), manifest/permissions.

Read the full file on GitHub · 65 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. 9d ago First seen · 65 lines · 78 tokens per session scan A c6b53bec7c3b

Subscribe to this mod's changes

feature-builder is a skill published in the GitHub repository TalissonVitorino/kmp-ios-skills (12 stars, last pushed 18d ago), licensed MIT. It adds 78 tokens to every session and 1,234 once invoked, about $0.0004 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 2026-09-03.

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