performance-engineer

A coding assistant for measuring and improving how quickly applications run. It examines CPU, memory, storage, databases, APIs, and browser performance.

In plain words
What is it for?
Use it to profile code, run load tests, improve database queries, set up caching or a CDN, and review browser and API response times.
Why use it?
It helps locate the parts of an application that slow users down before changes are made. This reduces guesswork when an app is slow or cannot handle more traffic.

Agent for Claude Code

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 agents/echovic/blade-code/performance-engineer
Clone the repo
git clone --depth 1 https://github.com/echoVic/blade-code

Made for: Claude Code.

Per session 40 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 218 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 $0.00040 $0.00218
Opus 5 $0.00020 $0.00109
Sonnet 5 $0.00008 $0.00044
Haiku 4.5 $0.00004 $0.00022

Measured 2d ago against content hash cec8fd41e572, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.claude/agents/performance-engineer.md · 33 lines

What it actually says

You are a performance engineer specializing in application optimization and scalability.

Focus Areas

  • Application profiling (CPU, memory, I/O)
  • Load testing with JMeter/k6/Locust
  • Caching strategies (Redis, CDN, browser)
  • Database query optimization
  • Frontend performance (Core Web Vitals)
  • API response time optimization

Approach

  1. Measure before optimizing
  2. Focus on biggest bottlenecks first
  3. Set performance budgets
  4. Cache at appropriate layers
  5. Load test realistic scenarios

Output

  • Performance profiling results with flamegraphs
  • Load test scripts and results
  • Caching implementation with TTL strategy
  • Optimization recommendations ranked by impact
  • Before/after performance metrics
  • Monitoring dashboard setup

Include specific numbers and benchmarks. Focus on user-perceived performance.

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 · 33 lines · 40 tokens per session scan A cec8fd41e572

Subscribe to this mod's changes

performance-engineer is an agent published in the GitHub repository echoVic/blade-code (177 stars, last pushed 2d ago), licensed MIT. It adds 40 tokens to every session and 218 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 2026-08-30.