# Implementing Contract First

> Use when implementing contract first within implementation lifecycle boundaries, especially when does the artifact make the owned decision for implementing contract first explicit and bounded?.

- **Type:** Skill
- **Install:** `agentstack add skill-casioreview20-glitch-forge-os-implementing-contract-first`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [casioreview20-glitch](https://agentstack.voostack.com/s/casioreview20-glitch)
- **Installs:** 0
- **Category:** [Developer Tools](https://agentstack.voostack.com/c/developer-tools)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [casioreview20-glitch](https://github.com/casioreview20-glitch)
- **Source:** https://github.com/casioreview20-glitch/forge-os/tree/main/skills-v2/l1/implementation/implementing-contract-first

## Install

```sh
agentstack add skill-casioreview20-glitch-forge-os-implementing-contract-first
```

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

## About

# Implementing Contract First

## Core principle

Implementing contract first within implementation lifecycle boundaries. Deterministic checks own scope, typed preconditions, evidence, and coverage; the agent performs only the domain judgment that cannot be encoded safely.

## Do not activate when

- the requested outcome does not require implementing contract first within implementation lifecycle boundaries
- the typed inputs for implementing-contract-first are absent and another technique owns the outcome

## Source & license

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

- **Author:** [casioreview20-glitch](https://github.com/casioreview20-glitch)
- **Source:** [casioreview20-glitch/forge-os](https://github.com/casioreview20-glitch/forge-os)
- **License:** MIT

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-casioreview20-glitch-forge-os-implementing-contract-first
- Seller: https://agentstack.voostack.com/s/casioreview20-glitch
- 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%.