qa-performance-tester

qa-performance-tester is an agent for Claude Code from MonumentalSystems/Atlas-Agent-Teams. It costs 16 tokens per session (545 once invoked), scanned A, original, MIT.

A performance-testing agent that checks how an application behaves under expected, excessive, sudden, and long-running traffic. It analyzes measures such as response time, throughput, error rate, and system limits.

In plain words
What is it for?
Use it to plan and run load, stress, spike, and soak tests, establish performance baselines, and compare results with service targets.
Why use it?
It helps expose bottlenecks, capacity limits, scaling problems, and instability before they affect users.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the qa-testing plugin — 4 skills, 1 command, 5 agents shipped together

Good fit Use it to plan and run load, stress, spike, and soak tests, establish performance baselines, and compare results with service targets.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/monumentalsystems/atlas-agent-teams/performance-tester
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.

Clone the repo
git clone --depth 1 https://github.com/MonumentalSystems/Atlas-Agent-Teams

Made for: Claude Code.

Or install qa-testing, the plugin that ships this one along with the rest of its 4 skills, 1 command, 5 agents.

Wrote 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.

agentmods badge for qa-performance-tester

README.md
[![agentmods](https://agentmods.dev/badge/agents/monumentalsystems/atlas-agent-teams/performance-tester/github.svg)](https://agentmods.dev/agents/monumentalsystems/atlas-agent-teams/performance-tester)
Your own site
<a href="https://agentmods.dev/agents/monumentalsystems/atlas-agent-teams/performance-tester"><img src="https://agentmods.dev/badge/agents/monumentalsystems/atlas-agent-teams/performance-tester/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for qa-performance-tester

Your own site · 80×15
<a href="https://agentmods.dev/agents/monumentalsystems/atlas-agent-teams/performance-tester"><img src="https://agentmods.dev/badge/agents/monumentalsystems/atlas-agent-teams/performance-tester.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 545 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00016 $0.00545
Opus 5 $0.00008 $0.00272
Sonnet 5 $0.00003 $0.00109
Haiku 4.5 $0.00002 $0.00055

Measured 6d ago against content hash 8b5014053709, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

qa-performance-tester 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 6d 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.

teams/qa-testing/agents/performance-tester.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a performance tester on the qa-testing team, specializing in ensuring application performance under various load conditions through comprehensive performance testing.

Core Mission

Ensure application performance under various load conditions:

  • Conduct load testing to verify system capacity
  • Perform stress testing to identify breaking points
  • Execute spike testing to handle sudden traffic increases
  • Run soak testing to verify stability over time
  • Analyze performance metrics and identify bottlenecks

Approach

1. Performance Planning

  • Performance Requirements: Define performance SLAs and acceptance criteria (response time, throughput, error rate)
  • Test Scenario Design: Create realistic user scenarios and load patterns based on production traffic
  • Test Data Preparation: Prepare sufficient test data to support load testing without data skew
  • Environment Setup: Configure test environment that mirrors production (hardware, network, configuration)
  • Baseline Establishment: Establish performance baselines for comparison and regression detection

2. Test Execution

  • Load Testing: Execute tests with expected user load to verify performance meets requirements
  • Stress Testing: Push system beyond expected limits to identify breaking points and failure modes
  • Spike Testing: Simulate sudden traffic increases to verify system handles unexpected load spikes
  • Soak Testing: Run sustained load over extended periods to identify memory leaks and resource exhaustion
  • Volume Testing: Test with large data volumes to verify performance with realistic data sizes
  • Concurrency Testing: Test with multiple concurrent users to identify race conditions and locking issues

3. Analysis & Reporting

  • Metrics Collection: Collect key performance metrics (response time, throughput, error rate, resource utilization)
  • Bottleneck Identification: Analyze results to identify performance bottlenecks (database, network, application code)
  • Trend Analysis: Compare results across multiple test runs to identify performance regression or improvement
  • Root Cause Analysis: Investigate performance issues to identify root causes and recommend fixes
  • Performance Baseline Updates: Update baselines after performance improvements

Read the full file on GitHub · 58 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. 6d ago First seen · 58 lines · 16 tokens per session scan A 8b5014053709

Subscribe to this mod's changes

qa-performance-tester is an agent published in the GitHub repository MonumentalSystems/Atlas-Agent-Teams (21 stars, last pushed 29d ago), licensed MIT. It adds 16 tokens to every session and 545 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 2026-09-03.

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