Guide · Agent skill
How to use the Interaction to Next Paint Audit agent skill
Updated · written with AI from the project's own documentation and checked against our catalogue data
The Interaction to Next Paint Audit skill is a set of written instructions that tells an AI agent how to check whether a web page responds quickly to clicks, taps and typing. It is aimed at front-end developers who want help diagnosing sluggish pages measured by Google's INP metric. After this guide you will know what the skill changes about the agent's behaviour, how to install it, how to ask for it in plain language, and what to check before trusting its advice.
Interaction to Next Paint Auditthedaviddias/Front-End-Checklist · MIT Download the skill Quick start
- 1Download and unzip. Download the skill ZIP from this page and unzip it so you have a folder containing SKILL.md.
- 2Place the folder. Move it to ~/.claude/skills/ for personal use or to .claude/skills/ inside a project. Alternatively, upload it in the Claude apps under Settings, Capabilities, Skills.
- 3Collect a measurement. Record the slow interaction in Chrome DevTools, or run Lighthouse or PageSpeed Insights, so you have real timing data.
- 4Ask in plain language. Describe the symptom and attach your measurements, for example that clicks take over 200ms on a specific page.
- 5Verify the bottleneck. Check that the agent identifies the specific long task, handler or asset before accepting a fix.
- 6Apply and re-measure. Make one change at a time, then re-run the same test to confirm interactions now respond within 200ms.
What the skill makes the agent do
Agent skills are folders of instructions that an AI assistant loads when a task matches them. This skill covers Google's Interaction to Next Paint (INP) metric, which measures how quickly a page responds to user interactions across the whole visit, not just the first one. INP replaced First Input Delay as a Core Web Vital in 2024.
The skill tells the agent to verify the real bottleneck before recommending changes, using Chrome DevTools, Lighthouse, PageSpeed Insights or field data. Its target is interaction responses within 200ms. Once a bottleneck is confirmed, the skill points the agent toward fixes such as breaking up long tasks, using web workers for heavy computation, and optimizing event handlers.
- Checks whether interactions respond within 200ms
- Asks for measurement before suggesting changes
- Recommends breaking up long tasks, web workers and lighter event handlers
- Reviews routes, assets and loading behaviour and names the measurement method used
Install the skill from the ZIP download
Download the ZIP for this skill from this page and unzip it. For a personal install, place the resulting folder in ~/.claude/skills/. For a single project, place it in that project's .claude/skills/ folder so it applies only there.
If you use the Claude apps instead, open Settings, go to Capabilities, and upload the skill under Skills. The skill folder should contain SKILL.md at its top level, along with references/rule.md.
- Personal: ~/.claude/skills/
- Project only: .claude/skills/ inside your project
- Claude apps: Settings → Capabilities → Skills, then upload
Trigger the skill with natural requests
You do not need a special command. The skill's description says it applies when auditing slow page loads, heavy assets, or rendering delays related to interaction responsiveness, so ask the agent in those terms. Including your measurements in the request makes the result far more useful, because the skill asks the agent to confirm the bottleneck first.
- "Our checkout form lags when users type. Audit the interaction responsiveness and tell me what to measure first."
- "Review this click handler and the code around it for INP problems, and flag exact files and steps that add main thread cost."
- "Here is my DevTools performance trace showing 350ms interactions. Where is the long task coming from?"
Example: reviewing a long synchronous loop
The reference file contrasts a single long synchronous loop that blocks the main thread with a version that yields periodically so pending interactions can be handled. It also shows a scheduler-based variant. When you ask the agent to review code like this, it should point to the specific loop and explain how it affects responsiveness.
Treat the reference snippets as patterns to adapt, not code to paste. The yield interval and the approach depend on your own app and on what your profiling shows.
// Good: Yield to main thread periodically
async function processLargeArrayAsync(items) {
for (let i = 0; i < items.length; i++) {
expensiveOperation(items[i])
if (i % 100 === 0) {
await yieldToMain()
}
}
}What the skill needs and safety notes
The skill lists no required dependencies. It does not run scripts and does not use the network, so it only supplies instructions to the agent. The results depend on the data you give it: without a DevTools trace, Lighthouse report or field data, the agent may return generic advice.
Because the skill itself does not execute code, the risk comes from acting on advice you have not verified. Test any change in a browser and re-measure INP before shipping it.
- Requires: nothing listed
- Runs scripts: no
- Uses network: no
- Marked advanced; plan around 30 minutes for the reference material
Tips for better results
Give the agent real numbers. A trace or report showing which interaction is slow and how long it takes lets the agent confirm the cause instead of guessing. Ask it to name the measurement method it relied on so you can repeat the test yourself.
- Record an interaction in Chrome DevTools and share the slow event's timing
- Share the handler code and the routes or assets that load on that page
- Ask for a before-and-after measurement plan for each proposed fix
- Re-run the same test after each change
What people use it for
- Diagnosing why a form or search box lags while users type
- Reviewing click handlers for heavy synchronous work that blocks the main thread
- Planning how to break a long data-processing loop into smaller chunks
- Preparing a page for Core Web Vitals review by listing the measurements still needed
Frequently asked questions
How do I install the interaction to next paint skill?
Download the ZIP from this page and unzip it. Put the folder in ~/.claude/skills/ for personal use, or in a project's .claude/skills/ folder. In the Claude apps you can instead upload it under Settings, Capabilities, Skills.
Does this skill cost anything or need a licence?
The skill is listed under the MIT licence. The source does not list any price, so check the licence file in the repository for the terms that apply to you.
What does the skill require to run?
The skill lists no required dependencies. It does not run scripts and does not use the network, so it provides instructions to the agent rather than tools.
What is the target for Interaction to Next Paint?
The skill targets interaction responses within 200ms. It measures responsiveness across all interactions in a visit, not just the first one.
Is this skill a simple one-click speed fix?
No. The skill is marked advanced and needs browser profiling data to be meaningful. Without measurements, the agent may give generic advice.
How does this compare with running Lighthouse myself?
Lighthouse and PageSpeed Insights measure the page, while this skill guides an AI agent to interpret measurements and suggest fixes. The skill itself tells the agent to confirm the bottleneck with those tools first.
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Our verdict
This skill suits front-end developers who already have profiling data and want an AI assistant to help interpret it and suggest targeted fixes for slow interactions. It is not a good fit for non-developers wanting a one-click speed boost, or for anyone who will not measure before and after changes.
Download the skill