A guide to pytest, a Python tool for writing and running automated tests. It covers pytest's way of checking results with plain assert statements and supplying reusable test setup with fixtures.

Use it to write, run, debug, or configure Python tests with assertions, fixtures, and related pytest features.

It explains pytest-specific patterns that differ from Python's built-in unittest style and from testing tools in other languages.

pytest — Skill for Claude Code and Codex by dashed/claude-marketplace

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 dashed/claude-marketplace --skill pytest

Clone the repo

git clone --depth 1 https://github.com/dashed/claude-marketplace

Made for: Claude Code, Codex.

Its marketplace also offers this one on its own, as the plugin pytest — /plugin install pytest after adding the marketplace above.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/dashed/claude-marketplace/pytest/github.svg)](https://agentmods.dev/skills/dashed/claude-marketplace/pytest)

Your own site

<a href="https://agentmods.dev/skills/dashed/claude-marketplace/pytest"><img src="https://agentmods.dev/badge/skills/dashed/claude-marketplace/pytest/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/dashed/claude-marketplace/pytest"><img src="https://agentmods.dev/badge/skills/dashed/claude-marketplace/pytest.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 253 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,281 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 unknown 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.

Model	Per session	Once invoked
Fable 5.1	$0.00253	$0.04281
Opus 5.5	$0.00101	$0.01712
Sonnet 5.5	$0.00051	$0.00856
Haiku 4.5	$0.00025	$0.00428

Measured 2mo ago against content hash 96f4262a0193, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

pytest 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 2mo 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.

plugins/pytest/skills/pytest/SKILL.md · 322 lines

The source is not reproduced here

No licence file

Read it on GitHub

Files

What ships with it

9 files 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.

2mo ago First seen · 322 lines · 253 tokens per session scan A 96f4262a0193

Subscribe to this mod's changes

pytest is a skill published in the GitHub repository dashed/claude-marketplace (25 stars, last pushed 16d ago), with no licence file. It adds 253 tokens to every session and 4,281 once invoked, about $0.0010 per session on Opus 5.5. 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.

Languages Python Testing Unit testing

pytest next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
pytestdashed/claude-marketplace	Skill	25	16d ago	none	A	253	Claude Code, Codex
temporal-python-testingwshobson/agents	Skill	42k	yesterday	MIT	A	45	Claude Code
python-testingmicrosoft/agent-framework	Skill	15k	yesterday	MIT	A	29	Claude Code, Codex
adk-verify-snippetsgoogle/adk-python	Skill	22k	yesterday	Apache-2.0	C	149	Claude Code, Codex
adk-setupgoogle/adk-python	Skill	22k	yesterday	Apache-2.0	C	146	Claude Code
test-generatorvstorm-co/pydantic-deepagents	Skill	1.1k	7d ago	MIT	A	12	Claude Code, Codex
kb-python-developmentCommunity-Access/accessibility-agents	Skill	435	8d ago	MIT	A	39	Claude Code, Codex