> ## Documentation Index
> Fetch the complete documentation index at: https://www.opendirectory.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Agent Compatibility

> How opendirectory validates and enforces per-skill target compatibility across coding agents.

Every skill in opendirectory can declare an optional `compatibility` field in its `SKILL.md` YAML frontmatter to specify which coding agents it supports.

## Frontmatter Specification

```yaml theme={null}
---
name: my-awesome-skill
description: Scrapes a website and generates a targeted cold email.
compatibility: [codex, opencode]
author: your-github-username
version: 1.0.0
---
```

### Canonical Target Slugs

When `compatibility` is present, it must be a non-empty YAML array containing only canonical target slugs:

* `claude`
* `codex`
* `opencode`
* `gemini`
* `anti-gravity`
* `openclaw`
* `hermes`

<Tip>
  **Universal Skills:** Omit the `compatibility` key entirely when a skill supports all seven canonical targets.
</Tip>

***

## Validation & Enforcement Rules

The `@opendirectory.dev/skills` CLI and pull request validation pipeline strictly enforce compatibility metadata:

1. **Universal by omission:** If `compatibility` is omitted from `SKILL.md`, the skill is marked as compatible with `all` targets.
2. **Case-insensitive canonical matching:** Values inside the array are trimmed and matched case-insensitively (`Claude` normalizes to `claude`), and returned in canonical target order.
3. **Strict rejection of invalid values:** Empty arrays (`[]`), scalar strings (`compatibility: claude`), non-string items, unknown agent names, or legacy aliases (`claude-code`, `gemini-cli`) fail both PR validation (`scripts/validate-pr.ts`) and CLI installation.
4. **Install-time target check:** If a skill declares `compatibility: [claude, opencode]` and a user runs `install <skill> --target gemini`, the CLI blocks installation with an explicit message explaining which targets the skill supports.


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