use-js-interop SKILL.md skillB
use-js-interop from dotnet/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add dotnet/skills/use-js-interop@git:20260525.198e58cPins git:20260525.198e58c in mdr.lock. Pin the fingerprint instead.
- Audit grade
- B, 16 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- dotnet/skills
- Path
plugins/dotnet-blazor/skills/use-js-interop/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260525.198e58c, committed May 25, 2026
- Size
- 10,989 bytes
- Repository stars
- 5,836
- License
- MIT
Add, review, or fix JavaScript interop in Blazor components. USE FOR: calling JavaScript from Blazor, calling .NET from JavaScript, collocated .razor.js modules, IJSRuntime, IJSObjectReference lifecycle, DotNetObjectReference, ElementReference, timing rules for when JS is available, IAsyncDisposable disposal of JS references, server-side JS interop safety. DO NOT USE FOR: general Blazor component authoring without JS interop needs (use author-component), forms (use collect-user-input).
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
# JS Interop in Blazor
## 1. Collocated JS Modules
Always use collocated `.razor.js` files with `export` — never global `window.*` functions or `<script>` tags.
```javascript
// ChartPanel.razor.js — placed next to ChartPanel.razor
export function initialize(canvas, dotNetRef) { /* ... */ }
export function updateData(points) { /* ... */ }
export function dispose() { /* ... */ }
```
Import paths: same project = `"./Components/ChartPanel.razor.js"`, RCL = `"./_content/{AssemblyName}/..."`.
## 2. Lifecycle Timing
**All JS interop must happen in `OnAfterRenderAsync` or event handlers** — never in `OnInitialized`, `OnParametersSet`, or constructors. JS is not available during server prerendering.
Use a typed interop wrapper (see Section 4) — never call `InvokeAsync`/`InvokeVoidAsync` with raw string literals:
```csharp
private ChartInterop? _chart;
protected override async Task OnAfterRenderAsync(bool firstRender)
{
if (firstRender)
{
_chart = new ChartInterop(JS);
await _chart.InitializeAsync(_canvasRef);
}
}
```
**Parameter changes**: set a flag in `OnParametersSet`, apply in `OnAfterRenderAsync`:
```csharp
private bool _dataChanged;
…Read the whole file at its exact version.
How to install
mdr add dotnet/skills/use-js-interop@sha256:6bf1227510ef49d3The line at the top of this page pins the label git:20260525.198e58c, 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.
[](https://markdownregistry.com/a/art_pfrdpizwmcktfy7e)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on May 25, 2026.
Audit of the latest version
- fail: No script tag (matched: <script)
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (10989 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
Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.
Source
dotnet/skills · 5,836 stars · license MIT · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_pfrdpizwmcktfy7e GET https://markdownregistry.com/api/v1/resolve?ref=dotnet/skills/use-js-interop GET https://markdownregistry.com/api/v1/blob/6bf1227510ef49d3a3cc30bf7a15c6c300b0df25a964aec66a8012a4f1d113c5
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.