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.
npx agentmods add commands/peterblazejewicz/claude-plugins/webperfgit clone --depth 1 https://github.com/peterblazejewicz/claude-pluginsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/commands/peterblazejewicz/claude-plugins/webperf)<a href="https://agentmods.dev/commands/peterblazejewicz/claude-plugins/webperf"><img src="https://agentmods.dev/badge/commands/peterblazejewicz/claude-plugins/webperf.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00023 | $0.00794 |
| Opus 5 | $0.00012 | $0.00397 |
| Sonnet 5 | $0.00005 | $0.00159 |
| Haiku 4.5 | $0.00002 | $0.00079 |
Grade A, and why
webperf 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 41 lines — stays where its author put it; the contents beside it link to each section on GitHub.
/webperf targets .NET web front ends specifically — Blazor (Server / WebAssembly / Auto) and ASP.NET Core MVC / Razor Pages. Do not use it for utility libraries, CLIs, desktop apps (Avalonia / MAUI), or server-only code with no browser-facing output. For server-side runtime performance, use the dotnet-skills:performance-optimization-dotnet skill instead.
Determine the mode
Deep mode — activate when any of these is available:
- A Lighthouse JSON report file (e.g.
npx lighthouse <url> --output json --output-path ./report.json, ornpx -p chrome-devtools-mcp chrome-devtools lighthouse_audit --output-format=jsonfrom the Chrome DevTools MCP CLI) - A PageSpeed Insights JSON response (includes Lighthouse + CrUX)
- A CrUX API response (requires
CRUX_API_KEYorGOOGLE_API_KEY) - A DevTools performance trace
- A live URL plus the
chrome-devtoolsMCP server configured in the harness (the agent can capture metrics directly vialighthouse_auditandperformance_*tools) - The Chrome DevTools MCP CLI invoked locally (via
npx -p chrome-devtools-mcp chrome-devtools <tool>or afternpm i -g chrome-devtools-mcp) — the user runs commands likechrome-devtools lighthouse_audit --output-format=jsonand passes the JSON output to the agent
Quick mode — default when none of the above are available. The agent scans source (.razor / .cshtml / Program.cs / .csproj / wwwroot/) for structural anti-patterns and labels every finding as potential impact.
Run the audit
Spawn the web-performance-auditor subagent. Pass it explicitly:
- The files, components, or diff under review
- The rendering model when known (Blazor Server / WebAssembly / Auto, MVC, Razor Pages) — it changes which bottlenecks matter
- Any artifact paths (Lighthouse JSON, PSI JSON, CrUX response, trace) or pasted JSON content
- The target URL or page name when known
- A note on which mode you expect (Quick or Deep), so the agent surfaces missing inputs if Deep was intended
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.
- 4d ago First seen · 41 lines · 23 tokens per session scan A 30d20c1d478b
webperf is a command published in the GitHub repository peterblazejewicz/claude-plugins (7 stars, last pushed 2mo ago), licensed MIT. It adds 23 tokens to every session and 794 once invoked, about $0.0001 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 2026-08-31.
Other commands, from other repositories
specify
Create or update the feature specification from a natural language feature description.
speckit.git.validate
Validate current branch follows feature branch naming conventions.
speckit.assess.intake
Capture and normalize a raw idea (text, URL, ticket, or codebase pointer) into an intake note.
core-review
Review code changes against SpecOps project-specific patterns. Catches recurring failure modes from real PRs — tool abstraction violations, generated file drift, cross-platform gaps, variable inconsistencies, and more. Complements full-review-gate (generic quality) and pr-fix (applying bot comments).
brownfield-map
Run a complete brownfield analysis on the codebase and generate MASTER.md, summaries, risk scores, and all derived analytics.
pre-ship
Run the pre-ship quality gate checklist before publishing your agent.