l3-performance-optimization

A later optimization guide for Blazor applications that have already been migrated from Web Forms and are building and running correctly. It focuses on async code and modern .NET 10 performance patterns.

In plain words
What is it for?
Use it after the migration is functional to review async and await usage, database queries, rendering, and other performance-related patterns.
Why use it?
It separates performance work from the initial migration, reducing the risk of making broken code harder to diagnose.

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/fritzandfriends/blazorwebformscomponents/l3-performance-optimization
Any agent
npx skills add FritzAndFriends/BlazorWebFormsComponents --skill l3-performance-optimization
Clone the repo
git clone --depth 1 https://github.com/FritzAndFriends/BlazorWebFormsComponents

Made for: Claude Code, Codex.

Per session 98 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,703 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 $0.00098 $0.05703
Opus 5 $0.00049 $0.02851
Sonnet 5 $0.00020 $0.01141
Haiku 4.5 $0.00010 $0.00570

Measured 2d ago against content hash b526eb9b8d38, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

l3-performance-optimization 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.

migration-toolkit/skills/l3-performance-optimization/SKILL.md · 730 lines

How it starts

The opening of the file, as written. The whole thing — 730 lines — stays where its author put it; the contents beside it link to each section on GitHub.

L3: Post-Migration Performance Optimization

⚠️ WARNING: L3 optimization runs AFTER the app builds and works correctly. Do NOT apply L3 changes during initial migration. Use shims first (Session, Response, Request) for functional correctness, then optimize later if needed.

This skill is the optional fourth step in the migration pipeline. It applies after the app builds and runs correctly following L1 (automated), L2 (structural), and L3-architecture (data/identity) passes.

Related skills:

  • /bwfc-migration — Core markup migration (controls, expressions, layouts)
  • /bwfc-data-migration — EF6 → EF Core, architecture decisions
  • /bwfc-identity-migration — Authentication migration

When to Use This Skill

Apply L3 optimizations when:

  • The migrated app builds and runs without errors
  • You want measurable performance improvements beyond functional correctness
  • You are ready to modernize patterns to .NET 10 idioms

Do NOT run L3 before the app is functional. L3 assumes L1 + L2 + L3-architecture are complete. Applying async patterns to broken code makes debugging harder.


Confidence Levels

Each optimization in this skill is rated:

Rating Meaning
Safe Drop-in change, identical behavior, no review needed
⚠️ Review Almost always correct, but verify behavior in your specific context
🔴 Risky Possible semantic difference — review before committing

Usage Patterns

# Apply all safe optimizations to the whole project
"Run L3 optimization on the migrated ContosoUniversity app"

# Apply a single category
"Apply async/await fixes to Students.razor.cs"

# Report only — no changes
"Generate an L3 optimization report for AfterWingtipToys"

# Ask what's applicable
"What .NET 10 optimizations can we apply to this file?"

1. Async/Await Modernization ✅ Safe

The most impactful change in the L3 pass. Synchronous EF Core calls block the thread pool, hurting throughput under load. Web Forms code-behind often used synchronous DB calls; migrated code preserves that pattern by default.

Read the full file on GitHub · 730 lines

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 · 730 lines · 98 tokens per session scan A b526eb9b8d38

Subscribe to this mod's changes

l3-performance-optimization is a skill published in the GitHub repository FritzAndFriends/BlazorWebFormsComponents (449 stars, last pushed 2mo ago), licensed MIT. It adds 98 tokens to every session and 5,703 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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