locust

locust is a skill for Claude Code from aks-builds/quality-skills. It costs 116 tokens per session (2,524 once invoked), scanned A, original, MIT.

A Python tool for writing and running load tests, which send many simulated users or requests to an application. Test behavior is described in Python code, and runs can use a web interface or a command-line mode.

In plain words
What is it for?
Use it to model HTTP user behavior, explore performance through its web interface, run tests in continuous integration (CI), and distribute high-load runs across a coordinating process and worker processes. It fits teams already working with Python.
Why use it?
It shows how an application responds as traffic increases, helping find slow endpoints, capacity limits, and failures before users encounter them. Python teams can keep load scenarios near their other code and tests.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the quality-skills plugin — 57 skills shipped together

Good fit Use it to model HTTP user behavior, explore performance through its web interface, run tests in continuous integration (CI), and distribute high-load runs across a coordinating process and worker processes. It fits teams already working with Python.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/aks-builds/quality-skills/locust
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.

Any agent
npx skills add aks-builds/quality-skills --skill locust
Clone the repo
git clone --depth 1 https://github.com/aks-builds/quality-skills

Made for: Claude Code.

Or install quality-skills, the plugin that ships this one along with the rest of its 57 skills.

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 locust

README.md
[![agentmods](https://agentmods.dev/badge/skills/aks-builds/quality-skills/locust/github.svg)](https://agentmods.dev/skills/aks-builds/quality-skills/locust)
Your own site
<a href="https://agentmods.dev/skills/aks-builds/quality-skills/locust"><img src="https://agentmods.dev/badge/skills/aks-builds/quality-skills/locust/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 locust

Your own site · 80×15
<a href="https://agentmods.dev/skills/aks-builds/quality-skills/locust"><img src="https://agentmods.dev/badge/skills/aks-builds/quality-skills/locust.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 116 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,524 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 $0.00116 $0.02524
Opus 5 $0.00058 $0.01262
Sonnet 5 $0.00023 $0.00505
Haiku 4.5 $0.00012 $0.00252

Measured 10d ago against content hash 30fd4426704f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

locust 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 10d 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.

skills/locust/SKILL.md · 264 lines

How it starts

The opening of the file, as written. The whole thing — 264 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Locust

You are an expert in Locust — a Python-based, code-first load testing tool. Your goal is to help engineers design realistic Locust tests, scale them via master/worker distribution, and integrate them into CI. Don't fabricate Locust class methods, decorators, or CLI flags. When uncertain, point the reader to docs.locust.io.

Initial Assessment

Check .agents/qa-context.md (fallback: .claude/qa-context.md) before answering. Pay attention to:

  • Python ecosystem fit — Locust shines when the team is already Python-strong (Django/FastAPI/Flask backends, pytest test suite). For JS-only teams, k6 is usually a better fit.
  • HTTP client choiceHttpUser (requests-based, simpler) vs FastHttpUser (geventhttpclient, far higher per-worker throughput). For high-RPS targets, prefer FastHttpUser.
  • Distribution — Locust can run from one machine; for high load, master/worker (one machine coordinates, workers generate load).
  • Web UI vs headless — UI is great for design and exploration. CI runs --headless.
  • Reporting — Locust's built-in stats are decent; for time-series, export via the Prometheus exporter or push to InfluxDB.

If the file does not exist, ask: Python version, HTTP client preference (HttpUser / FastHttpUser), target RPS / concurrency, distribution needs, and CI reporting requirements.


Why Locust

  • Pure Python — write tests in the language your team already knows.
  • Code-first — no XML, no GUI dependency; tests live in version control.
  • Web UI for design — start/stop/adjust load live during exploration.
  • Master/worker distribution — scale horizontally.
  • Event hooks — extensive Python API for custom metrics, gating, integrations.

When not to use Locust:

  • Non-Python team → k6 / Gatling / Artillery / JMeter.
  • Very high single-node throughput needed and team doesn't want to manage workers → k6 with a higher per-binary ceiling may be simpler.
  • Need WebSocket / gRPC out of the box → community extensions exist but vary in maturity.

Read the full file on GitHub · 264 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 10d ago First seen · 264 lines · 116 tokens per session scan A 30fd4426704f

Subscribe to this mod's changes

locust is a skill published in the GitHub repository aks-builds/quality-skills (2 stars, last pushed today), licensed MIT. It adds 116 tokens to every session and 2,524 once invoked, about $0.0006 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.

Related

Other skills, from other repositories

incremental-python-programmer

Takes a Python repository and natural language feature description as input, implements the feature with proper code placement, generates comprehensive tests, and ensures all tests pass. Use when Claude needs to: (1) Add new features to existing Python projects, (2) Implement functions, classes, or modules based on…

ArabelaTso/Skills-4-SE · 110 tokens

python-regression-test-generator

Automatically generates regression tests for Python codebases by analyzing changes between old and new code versions and their existing tests. Migrates tests to work with new code, generates tests for new functionality, and creates mocks for external dependencies. Supports unittest and pytest frameworks. Use when…

ArabelaTso/Skills-4-SE · 70 tokens

directed-test-input-generator

Generate targeted test inputs to reach specific code paths and hard-to-reach behaviors in Python code. Use when: (1) Targeting uncovered branches or specific execution paths, (2) Need coverage-guided test generation, (3) Want to leverage LLM understanding of code semantics for meaningful test inputs, (4) Testing…

ArabelaTso/Skills-4-SE · 112 tokens

python-test-updater

Updates Python test code to work with new versions of the code being tested. Use when Claude needs to: (1) Update tests after code changes, (2) Fix broken tests due to signature changes, (3) Update assertions to match new behavior, (4) Add test cases for new functionality, (5) Analyze code differences and their test…

ArabelaTso/Skills-4-SE · 109 tokens

integration-test-generator

Generate integration tests for multiple interacting components in Python. Use when testing interactions between: (1) Multiple services or APIs (REST/GraphQL endpoints, microservices), (2) Database operations with repositories/ORMs (SQLAlchemy, Django ORM), (3) External services (payment gateways, email services…

ArabelaTso/Skills-4-SE · 113 tokens

tlaplus-spec-generator

Automatically generate TLA+ specifications from source code (C/C++, Python) for formal verification of distributed systems. Use when users need to: (1) Generate TLA+ specs from program implementations, (2) Model distributed systems, consensus protocols, or concurrent algorithms, (3) Extract state variables, actions…

ArabelaTso/Skills-4-SE · 118 tokens