A guide to writing, placing, and running tests for a server. It explains when to test through an MCP client and when to call server functions directly, including protocol tests for TypeScript and Python servers.

Use it to add server tests, run one test suite, test the protocol, or generate a coverage report.

It helps choose a test level and the correct command instead of testing through the wrong interface or running the wrong suite.

How modelcontextprotocol/servers configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to modelcontextprotocol/servers. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/modelcontextprotocol/servers/main/.claude/skills/testing/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/modelcontextprotocol/servers

Made for: Claude Code.

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/modelcontextprotocol/servers/testing/github.svg)](https://agentmods.dev/skills/modelcontextprotocol/servers/testing)

Your own site

<a href="https://agentmods.dev/skills/modelcontextprotocol/servers/testing"><img src="https://agentmods.dev/badge/skills/modelcontextprotocol/servers/testing/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/modelcontextprotocol/servers/testing"><img src="https://agentmods.dev/badge/skills/modelcontextprotocol/servers/testing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 72 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,189 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	$0.00072	$0.04189
Opus 5.5	$0.00029	$0.01676
Sonnet 5.5	$0.00014	$0.00838
Haiku 4.5	$0.00007	$0.00419

Measured 18d ago against content hash d739d95d11c2, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

testing 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 18d 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.

.claude/skills/testing/SKILL.md · 339 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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.

evals/evals.json 1018 B

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.

18d ago Changed d739d95d11c2
26d ago First seen · 339 lines · 72 tokens per session scan A 4c04427af3ad

Subscribe to this mod's changes

testing is a skill published in the GitHub repository modelcontextprotocol/servers (91,815 stars, last pushed yesterday), with no licence file. It adds 72 tokens to every session and 4,189 once invoked, about $0.0003 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 2026-10-12.

Testing

testing next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
testingmodelcontextprotocol/servers	Skill	92k	yesterday	none	A	72	Claude Code
research-engineerdavila7/claude-code-templates	Skill	33k	today	MIT	A	43	Claude Code, Codex
tika-eval-compareapache/tika	Skill	4.1k	yesterday	Apache-2.0	A	50	Claude Code, Codex
cua-driverdavidondrej/skills	Skill	4.3k	3d ago	MIT	A	68	Claude Code, Codex
jetson-validate-imageNVIDIA/skills	Skill	3.9k	yesterday	Apache-2.0	B	50	Claude Code, Codex
atmos-validationcloudposse/atmos	Skill	1.4k	today	Apache-2.0	A	31	Claude Code
tddcodewithmukesh/dotnet-claude-kit	Skill	805	2d ago	MIT	A	81	Claude Code

servers: Skill for Claude Code