mastra: Skill for Claude Code

.claude/skills/builder-smoke-test/SKILL.md

builder-smoke-test is a skill for Claude Code from mastra-ai/mastra. It costs 120 tokens per session (9,549 once invoked), scanned C, original, no licence file.

An end-to-end smoke test for Agent Builder, a feature for creating and managing agents, tested against a controlled sample project.

In plain words
What is it for?
Testing agent and skill creation, ownership, visibility, copying from a registry, allowed pickers, model rules, and role-based access.
Why use it?
It checks that the feature works across workspace setup, saved agents and skills, access rules, the library, model policies, and role restrictions.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is mastra-ai/mastra's own configuration. It tells Claude Code how to work on mastra itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything mastra configures →

Reuse

Borrowing it

Nothing to install: this file belongs to mastra-ai/mastra. 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/mastra-ai/mastra/main/.claude/skills/builder-smoke-test/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/mastra-ai/mastra

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.

agentmods badge for builder-smoke-test

README.md
[![agentmods](https://agentmods.dev/badge/skills/mastra-ai/mastra/builder-smoke-test/github.svg)](https://agentmods.dev/skills/mastra-ai/mastra/builder-smoke-test)
Your own site
<a href="https://agentmods.dev/skills/mastra-ai/mastra/builder-smoke-test"><img src="https://agentmods.dev/badge/skills/mastra-ai/mastra/builder-smoke-test/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 builder-smoke-test

Your own site · 80×15
<a href="https://agentmods.dev/skills/mastra-ai/mastra/builder-smoke-test"><img src="https://agentmods.dev/badge/skills/mastra-ai/mastra/builder-smoke-test.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 120 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 9,549 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 2 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00120 $0.09549
Opus 5 $0.00060 $0.04775
Sonnet 5 $0.00024 $0.01910
Haiku 4.5 $0.00012 $0.00955

Measured 11d ago against content hash e926e7055cd8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade C, and why

builder-smoke-test scanned grade C with 2 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 11d ago.

The scan reads SKILL.md. This mod also ships 9 executable files (assets/template/src/mastra/agents/index.ts, assets/template/src/mastra/auth.ts, assets/template/src/mastra/index.ts, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

- **Reset:** `rm -rf "$PROJECT_DIR"` (or re-run `scripts/scaffold.sh`

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

3. **Under `--auth on`, extract the session cookie before running any other section.** The WorkOS cookie is `httpOnly`, so `curl` cannot mint it and `document.cookie` cannot read it. The scaffold ships a debug route at `
.claude/skills/builder-smoke-test/SKILL.md · 519 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

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. 11d ago First seen · 519 lines · 120 tokens per session scan C e926e7055cd8

Subscribe to this mod's changes

builder-smoke-test is a skill published in the GitHub repository mastra-ai/mastra (27,896 stars, last pushed yesterday), with no licence file. It adds 120 tokens to every session and 9,549 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it C with 2 findings (recursive force delete, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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