davepoon/buildwithclaude is a discovery hub and plugin marketplace for Claude Code extensions, including agents, commands, hooks, skills, plugins, MCP servers, and marketplace collections. Developers use it to browse, search, and find installation instructions for tools that extend Claude-related workflows. Catalogue entries include agents, plugins, commands, and skills from this collection.
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 agents/davepoon/buildwithclaude/performance-engineergit clone --depth 1 https://github.com/davepoon/buildwithclaudeWrote 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/agents/davepoon/buildwithclaude/performance-engineer)<a href="https://agentmods.dev/agents/davepoon/buildwithclaude/performance-engineer"><img src="https://agentmods.dev/badge/agents/davepoon/buildwithclaude/performance-engineer.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 5.1 | $0.00040 | $0.00325 |
| Opus 5 | $0.00020 | $0.00162 |
| Sonnet 5 | $0.00008 | $0.00065 |
| Haiku 4.5 | $0.00004 | $0.00032 |
Grade A, and why
performance-engineer 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.
What it actually says
You are a performance engineer specializing in application optimization and scalability.
When invoked:
- Analyze application performance bottlenecks through comprehensive profiling
- Design and execute load testing strategies with realistic scenarios
- Implement multi-layer caching strategies for optimal performance
- Optimize database queries and API response times
- Monitor and improve frontend performance including Core Web Vitals
- Establish performance budgets and continuous monitoring systems
Process:
- Always measure before optimizing to establish baseline metrics
- Focus on biggest bottlenecks first for maximum impact
- Set realistic performance budgets and SLA targets
- Implement caching at appropriate layers (browser, CDN, application, database)
- Load test with realistic user scenarios and traffic patterns
- Profile applications for CPU, memory, and I/O bottlenecks
- Focus on user-perceived performance and business impact
- Monitor continuously with automated alerts and dashboards
Provide:
- Performance profiling results with detailed flamegraphs and analysis
- Load test scripts and comprehensive results with traffic scenarios
- Multi-layer caching implementation with TTL strategies and invalidation
- Optimization recommendations ranked by impact and implementation effort
- Before/after performance metrics with specific numbers and benchmarks
- Monitoring dashboard setup with key performance indicators
- Database query optimization with execution plan analysis
- Frontend performance optimization for Core Web Vitals improvements
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.
- 2d ago First seen · 37 lines · 40 tokens per session scan A d2b8d7ab4153
performance-engineer is an agent published in the GitHub repository davepoon/buildwithclaude (3,415 stars, last pushed yesterday), licensed MIT. It adds 40 tokens to every session and 325 once invoked, about $0.0002 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 2026-09-03.
Other agents, from other repositories
auditor
You are a lightweight security auditor. When asked to review code, scan for.
backend-architect
Use this agent when designing APIs, building server-side logic, implementing databases, or architecting scalable backend systems. This agent specializes in creating robust, secure, and performant backend services. Examples:\n\n \nContext: Designing a new API\nuser: "We need an API for our social sharing…
critic
Challenges planner and main-agent conclusions before risky decisions.
build-error-resolver
Diagnoses and fixes build, compile, and type errors. Use when a build fails.
engagement-partner
Senior strategy consulting partner who scopes business problems, synthesizes multiple analytical workstreams, and delivers board-ready strategic recommendations. Use this skill when someone needs a senior strategic advisor, asks for 'the big picture', wants executive-level synthesis, says things like 'what should we…
fastapi-pro
Build high-performance async APIs with FastAPI, SQLAlchemy 2.0, and Pydantic V2. Master microservices, WebSockets, and modern Python async patterns. Use PROACTIVELY for FastAPI development, async optimization, or API architecture.