Getting Started

In this tutorial, you’ll install OntoSkills and run your first SPARQL query against a compiled skill ontology.

What you’ll have at the end:

A working OntoSkills installation
A skill installed from OntoStore
A successful SPARQL query result

Time: ~5 minutes

Prerequisites

Before you start, make sure you have:

Node.js 18+ (install)
Git (install)
Anthropic API key (get one at console.anthropic.com)

Step 1: Install the CLI

Open your terminal and run:

npx ontoskills install mcp

This creates a managed home at ~/.ontoskills/ with:

bin/ontomcp — the MCP runtime
ontologies/ — compiled ontology packages
state/ — lockfiles and metadata

Expected output:

✓ Installed ontomcp to ~/.ontoskills/bin/ontomcp
✓ Created ~/.ontoskills/ontologies/
✓ Created ~/.ontoskills/state/

Step 2: Install a skill from OntoStore

OntoStore is built in. Let’s install a greeting skill:

ontoskills search hello

Expected output:

Found 1 skill:
  mareasw/greeting/hello - Simple greeting skill

Install it (auto-enabled on install):

ontoskills install mareasw/greeting/hello

Expected output:

✓ Installed mareasw/greeting/hello

Step 3: Query the skill

Now let’s query the installed skill using SPARQL:

ontoskills query "SELECT ?skill ?intent WHERE { ?skill a oc:Skill . ?skill oc:resolvesIntent ?intent }"

Expected output:

?skill                    ?intent
─────────────────────────────────────
skill:hello               "say_hello"

You just queried a compiled ontology. The result is deterministic — same query, same result, every time.

Step 4: (Optional) Install the compiler

If you want to write custom skills from source, install the compiler:

ontoskills install core

Requirements:

Python 3.10+
ANTHROPIC_API_KEY environment variable set

export ANTHROPIC_API_KEY="your-key-here"
ontoskills init-core

This creates core.ttl — the base ontology with classes and properties.

Step 5: (Optional) Write your first skill

Create a simple skill:

mkdir -p skills/my-first-skill

Create skills/my-first-skill/SKILL.md:

# My First Skill

A simple demonstration skill.

## What It Does

This skill greets the user by name.

## When To Use

Use when the user wants a friendly greeting.

## How To Use

1. Ask for the user's name
2. Say "Hello, {name}!"

Compile it:

ontoskills compile my-first-skill

Expected output:

✓ Compiled my-first-skill
  Nature: A simple demonstration skill
  Intents: greet_user

Query your skill:

ontoskills query "SELECT ?intent WHERE { skill:my_first_skill oc:resolvesIntent ?intent }"

What you learned

How to install OntoSkills CLI and MCP runtime
How to install skills from OntoStore
How to query skills with SPARQL
(Optional) How to write and compile your own skill

Next steps

Now that you’re set up:

Goal	Read
Learn all CLI commands	CLI Reference
Browse available skills	OntoStore
Write custom skills	Skill Authoring
Understand how it works	Architecture
Connect to your AI client	MCP Setup
Fix issues	Troubleshooting

Common issues

”Command not found: ontoskills”

Make sure you ran npx ontoskills install mcp and the ~/.ontoskills/bin directory is in your PATH, or use npx ontoskills as the command.

”ANTHROPIC_API_KEY not set”

export ANTHROPIC_API_KEY="your-key-here"

Add this to your shell profile (~/.bashrc, ~/.zshrc) to persist.

”No skills found”

Skills are enabled by default on install. If you previously disabled one, re-enable it:

ontoskills enable mareasw/greeting/hello

“SHACL validation failed”

Your skill is missing required fields. Check:

At least one resolvesIntent
The skill has clear structure

Run with -v for details:

ontoskills compile my-skill -v