# External Skill Fixture Builder

> Turn external skill, rule, plugin, MCP, task-memory, and multi-agent workspace patterns into safe fixture coverage rather than live dependencies.

- **Type:** Skill
- **Install:** `agentstack add skill-45ck-skill-harness-external-skill-fixture-builder`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [45ck](https://agentstack.voostack.com/s/45ck)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [45ck](https://github.com/45ck)
- **Source:** https://github.com/45ck/skill-harness/tree/main/packs/agent-operating-skills/skills/external-skill-fixture-builder
- **Website:** https://github.com/45ck/skill-harness/releases/tag/v0.1.0

## Install

```sh
agentstack add skill-45ck-skill-harness-external-skill-fixture-builder
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# External Skill Fixture Builder

Use this skill when a third-party ecosystem pattern should be tested by `skill-harness` but should not become a live dependency.

## Process

- Choose the fixture lane by install posture, not by brand:
  - pure `SKILL.md` pack
  - plugin manifest
  - Cursor `.mdc` rules
  - Codex/Claude/Cursor subagents
  - MCP/tool config
  - generated record/replay skill
  - Beads or task-memory repo
  - multi-agent workspace layout
- Use minimal synthetic fixtures when possible.
- Use pinned external snapshots only when real structure matters and license/provenance allows it.
- Keep fixtures out of global user directories and live install caches.
- Make the fixture assert one behavior: parse, classify, trust recommendation, drift detection, render target, or installer opt-in.
- Add a command or check that proves the fixture is exercised.

## Output

### Fixture Lane
### Source Or Synthetic Basis
### Files Included
### Expected Classification
### Risk Flags Expected
### Check Command
### Follow-Up Adoption Question

## Avoid

- making fixtures large mirrors of public repos
- using fixtures as a back door for third-party adoption
- mixing fixture coverage with default installer behavior
- storing credentials, real traces, browser recordings, or private task state in fixtures

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [45ck](https://github.com/45ck)
- **Source:** [45ck/skill-harness](https://github.com/45ck/skill-harness)
- **License:** MIT
- **Homepage:** https://github.com/45ck/skill-harness/releases/tag/v0.1.0

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-45ck-skill-harness-external-skill-fixture-builder
- Seller: https://agentstack.voostack.com/s/45ck
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.