shiny-r-optimize SKILL.md skillA

shiny-r-optimize from posit-dev/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned
mdr add posit-dev/skills/shiny-r-optimize@v1.0

Pins v1.0 in mdr.lock. Pin the fingerprint instead.

Audit grade
A, 17 of 17 checks passed
Kind
SKILL.md skill
Repository
posit-dev/skills
Path
shiny/shiny-r-optimize/SKILL.md
Versions recorded
1
Latest version
v1.0, committed Oct 14, 2026
Size
13,360 bytes
Repository stars
556
License
MIT

Diagnose and fix performance problems in Shiny for R apps — slow startup, sluggish interactions, long-running blocking operations, and apps that struggle beyond a handful of concurrent users. Use when a Shiny app is slow, hangs, recomputes too much, times out, or needs to support more users; when the user asks to "speed up", "optimize", or "make faster" an existing Shiny app; or when preparing a prototyped app for real-world traffic.

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

# Optimizing Shiny App Performance

Make an existing Shiny for R app faster without changing what it does. The
typical user has an app that worked fine for one or two developers and is now
too slow or must support more users. Keep all app logic intact; prefer code
changes over deployment tuning; resist rewrites.

Order of preference for every fix:

1. **Eliminate** work that isn't needed (don't compute outputs nobody is
   looking at; don't compute with inputs that aren't ready).
2. **Reuse** work that repeats (shared reactives, caching).
3. **Accelerate** unavoidable work (faster data formats, vectorized code).
4. **Relocate** work that blocks (async / background tasks) — last resort; it
   buys concurrency, not raw speed.

## Workflow

### 1. Understand the complaint

Pin down what "slow" means and write it as a benchmark to beat:

- **What feels slow?** First page load? Every interaction? One specific
  action? Only when several people use it at once?
- **How many concurrent users** must it support? (1–5, ~20, hundreds?)
- **Where does it run?** Locally, Posit Connect, Posit Connect Cloud, Shiny
  Server?
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint
mdr add posit-dev/skills/shiny-r-optimize@sha256:edd68fc3f3cc6f00

The line at the top of this page pins the label v1.0, 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_gikfhehhpnh4b7qx.svg)](https://markdownregistry.com/a/art_gikfhehhpnh4b7qx)

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

Versions

The registry has recorded 1 version of this file, committed on Oct 14, 2026.

versioncommittedcommitsizeaudit
v1.0 latest2026-10-14 ea89446 13,360 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 (13360 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

posit-dev/skills · 556 stars · license MIT · pushed 2026-11-02 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_gikfhehhpnh4b7qx
GET https://markdownregistry.com/api/v1/resolve?ref=posit-dev/skills/shiny-r-optimize
GET https://markdownregistry.com/api/v1/blob/edd68fc3f3cc6f00121411e90d6e196d3b937044f6a841719e62ca89792fbc74

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.

More from posit-dev/skills

AGENTS.md AGENTS.md file
posit-dev/skills · AGENTS.md
git:20261007.4d770f9 · audit A · 556 stars
alt-text SKILL.md skill
posit-dev/skills · alt-text/SKILL.md · Generate and improve accessible alt text for data visualizations and images in R packages and Quarto documents. Use…
v1.0 · audit A · 556 stars
brand-yml SKILL.md skill
posit-dev/skills · brand-yml/SKILL.md · Create and use brand.yml files for consistent branding across Shiny apps and Quarto documents. Covers: (1) Creating new…
v1.1 · audit A · 556 stars
deploy-to-connect SKILL.md skill
posit-dev/skills · connect/deploy-to-connect/SKILL.md · Deploy or publish Python and R content to a Posit Connect server using rsconnect-python or the R rsconnect package…
v4.0 · audit A · 556 stars
ggsql SKILL.md skill
posit-dev/skills · ggsql/ggsql/SKILL.md · Write ggsql queries — a grammar of graphics for SQL. Use when the user wants to create, modify, or understand a ggsql…
v1.1 · audit A · 556 stars
pr-create SKILL.md skill
posit-dev/skills · github/pr-create/SKILL.md · Creates a pull request from current changes, monitors GitHub CI, and debugs any failures until CI passes. Activate when…
v1.5 · audit A · 556 stars
pr-threads-address SKILL.md skill
posit-dev/skills · github/pr-threads-address/SKILL.md · Address PR review feedback by systematically working through every unresolved PR review thread on the current branch's…
v1.0 · audit A · 556 stars
pr-threads-resolve SKILL.md skill
posit-dev/skills · github/pr-threads-resolve/SKILL.md · Bulk resolve unresolved PR review threads on the current branch’s PR — typically after threads have been addressed…
v1.0 · audit A · 556 stars
create-release-checklist SKILL.md skill
posit-dev/skills · open-source/create-release-checklist/SKILL.md · Create a release checklist and GitHub issue for an R package. Use when the user asks to "create a release checklist" or…
v1.0 · audit A · 556 stars
maintainer-decline SKILL.md skill
posit-dev/skills · open-source/maintainer-decline/SKILL.md · Guide for drafting issue closure and decline responses as an open-source package maintainer. Use when helping compose a…
git:20260521.928d934 · audit A · 556 stars
release-post SKILL.md skill
posit-dev/skills · open-source/release-post/SKILL.md · Create professional package release blog posts following Tidyverse or Shiny blog conventions. Use when the user needs…
v1.0 · audit A · 556 stars
critical-code-reviewer SKILL.md skill
posit-dev/skills · posit-dev/critical-code-reviewer/SKILL.md · Rigorously review code or pull requests for correctness, security, accessibility, maintainability, tests, and edge…
v1.2 · audit A · 556 stars

Every file in posit-dev/skills

Browse by kind, by grade A, or by owner.