mobile-rn-performance SKILL.md skillA

This file is byte-identical to the first copy the registry indexed. Same content hash, so the same checks give both the same grade.

mobile-rn-performance from kensaurus/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned
mdr add kensaurus/skills/mobile-rn-performance@git:20261006.f722601

Pins git:20261006.f722601 in mdr.lock. Pin the fingerprint instead.

Audit grade
A, 17 of 17 checks passed
Kind
SKILL.md skill
Repository
kensaurus/skills
Path
skills/mobile-rn-performance/SKILL.md
Versions recorded
5
Latest version
git:20261006.f722601, committed Oct 6, 2026
First version recorded
Jun 4, 2026
Size
6,872 bytes
Repository stars
9
License
MIT

Fix React Native / Expo performance, build, and upgrade issues: jank, slow startup, large bundles, memory leaks, Hermes, FlashList, Reanimated, Turbo Modules, 16KB alignment, SDK upgrades.

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

# React Native Performance & Build

**Degree of freedom: MIXED.** Which category and fix `[HIGH freedom]`; measure
before/after, 16KB alignment, and upgrade-helper diffs
`[LOW freedom — run exactly]`.

> The performance, bundling, and upgrade layer for React Native / Expo. `mobile-rn-screen` handles screen layout and native feel; this skill handles *speed, size, and version moves*.
>
> Distilled from [Callstack's React Native best-practices skill](https://github.com/callstackincubator/agent-skills) (MIT) and the Ultimate Guide to RN Optimization.

## How to reason

1. **Measure** — RN perf monitor / profiler numbers first
2. **Category** — FPS, bundle, TTI, native, memory, or animation
3. **Fix** — the profiled hotspot only
4. **Re-measure** — before/after on a real low-end device

## Worked example

> **Measure:** feed scroll drops to 38fps; React profiler shows every row re-rendering.
> **Category:** FPS & re-renders — not "add memo everywhere".
> **Fix:** `FlashList` + stable `keyExtractor`; animation stays on Reanimated shared values.
> **Re-measure:** 56fps on a low-end Android; no new storm on the changed screen.

## Self-critique before reporting
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint
mdr add kensaurus/skills/mobile-rn-performance@sha256:6f56cf848c22211f

The line at the top of this page pins the label git:20261006.f722601, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_m6j6k3nqo7hsnakb.svg)](https://markdownregistry.com/a/art_m6j6k3nqo7hsnakb)

2 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 5 versions of this file, between Jun 4, 2026 and Oct 6, 2026, about one every 31 days.

versioncommittedcommitsizeaudit
git:20261006.f722601 latest2026-10-06 f722601 6,872 BA view · diff
git:20260821.2a410312026-08-21 2a41031 6,142 BA view · diff
git:20260817.5b93a212026-08-17 5b93a21 4,906 BA view · diff
git:20260721.36a30862026-07-21 36a3086 4,760 BA view · diff
git:20260604.45202dd2026-06-04 45202dd 4,774 BA view

Audit of the latest version

A  17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (6872 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

kensaurus/skills · 9 stars · license MIT · pushed 2026-10-19 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_m6j6k3nqo7hsnakb
GET https://markdownregistry.com/api/v1/resolve?ref=kensaurus/skills/mobile-rn-performance
GET https://markdownregistry.com/api/v1/blob/6f56cf848c22211f7687d6d7e9d22e470da71f31b337b5ab41458579b2ed2860

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

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Every file in kensaurus/skills

Other files named mobile-rn-performance

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kensaurus/cursor-kenji · skills/mobile-rn-performance/SKILL.md · Fix React Native / Expo performance, build, and upgrade issues: jank, slow startup, large bundles, memory leaks…
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