dotnet-blazor

A guide for building Blazor applications, which create interactive web interfaces with C# and .NET instead of relying mainly on JavaScript.

In plain words
What is it for?
Designing Blazor components, selecting Server, WebAssembly, or Auto rendering, managing state, handling hydration, and connecting to JavaScript when needed.
Why use it?
It helps choose where the interface runs and avoid problems with components, state, prerendering, browser startup, and server communication.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/managedcode/prompterone/dotnet-blazor
Any agent
npx skills add managedcode/PrompterOne --skill dotnet-blazor
Clone the repo
git clone --depth 1 https://github.com/managedcode/PrompterOne

Made for: Claude Code, Codex.

Per session 37 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,692 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 86% copy Near-identical to another mod 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 $0.00037 $0.01692
Opus 5 $0.00018 $0.00846
Sonnet 5 $0.00007 $0.00338
Haiku 4.5 $0.00004 $0.00169

Measured 2d ago against content hash c16e76b97903, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

dotnet-blazor 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 2d 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.

Origin

This is a copy

86% identical to blazor — 9 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.codex/skills/dotnet-blazor/SKILL.md · 246 lines

How it starts

The opening of the file, as written. The whole thing — 246 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Blazor

Trigger On

  • building interactive web UIs with C# instead of JavaScript
  • choosing between Server, WebAssembly, or Auto render modes
  • designing component hierarchies and state management
  • handling prerendering and hydration
  • integrating with JavaScript when necessary

Documentation

References

  • patterns.md - Detailed component patterns, state management strategies, and JS interop techniques
  • anti-patterns.md - Common Blazor mistakes and how to avoid them

Render Modes (.NET 8+)

Mode Where It Runs Best For
Static Server (no interactivity) SEO pages, marketing content
InteractiveServer Server via SignalR Real-time apps, thin clients
InteractiveWebAssembly Browser via WASM Offline-capable, client-heavy
InteractiveAuto Server first, then WASM Best of both worlds

Applying Render Modes

@* Per-component *@
@rendermode InteractiveServer

@* Or in App.razor for global *@
<Routes @rendermode="InteractiveAuto" />

InteractiveAuto Architecture

First Request:
  Browser → Server (Interactive Server) → Fast response

Subsequent Requests:
  Browser → WASM (downloaded in background) → No server needed

Workflow

  1. Choose render mode based on requirements:
    • Need SEO? Start with Static or prerendering
    • Need real-time? Use InteractiveServer
    • Need offline? Use InteractiveWebAssembly
    • Want both? Use InteractiveAuto

Read the full file on GitHub · 246 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2d ago First seen · 246 lines · 37 tokens per session scan A c16e76b97903

Subscribe to this mod's changes

dotnet-blazor is a skill published in the GitHub repository managedcode/PrompterOne (42 stars, last pushed 3mo ago), licensed MIT. It adds 37 tokens to every session and 1,692 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to blazor, differing in 9 lines, and is treated as a copy.

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