How do I install the Ontology Syntax Validate skill?

Run npx skillmds@latest add daniel-dona/ontology-syntax-validate in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Ontology Syntax Validate safe to use?

This skill has not completed SkillMD's automated safety review yet. Capability flags: executes scripts, makes network calls. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Ontology Syntax Validate?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Ontology Syntax Validate free to use?

Yes. Installing skills from SkillMD is free. This skill is licensed under MIT.

Who published Ontology Syntax Validate?

daniel-dona (@daniel-dona) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Ontology Syntax Validate by daniel-dona

Name: Ontology Syntax Validate
Rating: 4.2 (5 reviews)
Author: daniel-dona

Ontology Syntax Validate

Provides a script and instructions to validate RDF syntax of every file in a repository using rapper (raptor2) with rdflib fallback. Covers Turtle, RDF/XML, N-Triples, JSON-LD, and more. Use before any other ontology check — if files don't parse, nothing else works.

daniel-dona Updated Sep 22, 2026

File contents

Ontology Syntax Validation

Validates that every RDF file in a repository is syntactically valid. Uses rapper from raptor2 (the reference RDF parser from the W3C ecosystem) as primary validator. Falls back to rdflib if rapper is not installed.

Single script: scripts/syntax_validate.py

Supported Formats

Extension	Format	Parser
`.ttl`	Turtle	rapper / rdflib
`.owl`	RDF/XML	rapper / rdflib
`.rdf`	RDF/XML	rapper / rdflib
`.nt`	N-Triples	rapper / rdflib
`.nq`	N-Quads	rapper
`.trig`	TriG	rapper / rdflib
`.jsonld`	JSON-LD	rdflib (rapper fallback)
`.html`, `.xhtml`	RDFa	rapper

Setup

Rapper is a system tool — install once:

sudo apt install raptor2-utils    # Debian/Ubuntu
brew install raptor               # macOS

For the rdflib fallback (if rapper is unavailable), use a venv:

python3 -m venv .venv
source .venv/bin/activate
pip install rdflib

After finishing: deactivate the venv and remove it (deactivate && rm -rf .venv). Skip this if the user asks to keep the environment.

If you only use rapper, skip the venv setup — rapper is a system tool.

Usage

python scripts/syntax_validate.py . -o SYNTAX_REPORT.md

# Force rdflib even if rapper is installed
python scripts/syntax_validate.py . --rdflib

# JSON output
python scripts/syntax_validate.py . --format json

Standardized Report

All skills support --format report which outputs a common JSON schema:

{
  "skill": "skill-name",
  "summary": {"errors": N, "warnings": N, "info": N},
  "issues": [{"file": ".ttl", "element": ":Class", "message": "...",
              "severity": "error|warning|info", "check": "RULE",
              "suggestion": "fix"}]
}

This format is consumed by ontology-full-audit to produce unified reports.

Output Files

Never write files into the repository without permission. Before generating any report or output file, ask the user where to save it (e.g. -o ../report.md or an absolute path outside the repo). The default output path in script examples is only a suggestion — always confirm with the user first.

Important Rules

Syntax validation is the first gate. If a file doesn't parse, no other skill (typo, SKOS, OOPS, SHACL) can process it. Run this first.
rapper is stricter than rdflib. It may flag valid-but-ambiguous constructs as warnings. Treat rapper errors as authoritative.
rapper is stricter than rdflib. It may flag valid-but-ambiguous constructs. The script automatically falls back to rdflib per file when rapper fails — check the report for ⚠️ rapper failed, parsed with rdflib notes to identify format mismatches.

---name: ontology-syntax-validatedescription: Provides a script and instructions to validate RDF syntax of every file in a repository using rapper (raptor2) with rdflib fallback. Covers Turtle, RDF/XML, N-Triples, JSON-LD, and more. Use before any other ontology check — if files don't parse, nothing else works.license: MIT---# Ontology Syntax ValidationValidates that every RDF file in a repository is syntactically valid. Uses**rapper** from [raptor2](https://librdf.org/raptor/) (the reference RDF parserfrom the W3C ecosystem) as primary validator. Falls back to **rdflib** ifrapper is not installed.**Single script:** `scripts/syntax_validate.py`## Supported Formats| Extension | Format | Parser ||-----------|--------|--------|| `.ttl` | Turtle | rapper / rdflib || `.owl` | RDF/XML | rapper / rdflib || `.rdf` | RDF/XML | rapper / rdflib || `.nt` | N-Triples | rapper / rdflib || `.nq` | N-Quads | rapper || `.trig` | TriG | rapper / rdflib || `.jsonld` | JSON-LD | rdflib (rapper fallback) || `.html`, `.xhtml` | RDFa | rapper |## SetupRapper is a system tool — install once:```bashsudo apt install raptor2-utils # Debian/Ubuntubrew install raptor # macOS```For the rdflib fallback (if rapper is unavailable), use a venv:```bashpython3 -m venv .venvsource .venv/bin/activatepip install rdflib```> **After finishing:** deactivate the venv and remove it (`deactivate && rm -rf .venv`).> Skip this if the user asks to keep the environment.If you only use rapper, skip the venv setup — rapper is a system tool.## Usage```bashpython scripts/syntax_validate.py . -o SYNTAX_REPORT.md# Force rdflib even if rapper is installedpython scripts/syntax_validate.py . --rdflib# JSON outputpython scripts/syntax_validate.py . --format json```## Standardized ReportAll skills support `--format report` which outputs a common JSON schema:```json{ "skill": "skill-name", "summary": {"errors": N, "warnings": N, "info": N}, "issues": [{"file": ".ttl", "element": ":Class", "message": "...", "severity": "error|warning|info", "check": "RULE", "suggestion": "fix"}]}```This format is consumed by `ontology-full-audit` to produce unified reports.## Output Files**Never write files into the repository without permission.** Before generatingany report or output file, ask the user where to save it (e.g. `-o ../report.md`or an absolute path outside the repo). The default output path in scriptexamples is only a suggestion — always confirm with the user first.## Important Rules1. **Syntax validation is the first gate.** If a file doesn't parse, no other skill (typo, SKOS, OOPS, SHACL) can process it. Run this first.2. **rapper is stricter than rdflib.** It may flag valid-but-ambiguous constructs as warnings. Treat rapper errors as authoritative.3. **rapper is stricter than rdflib.** It may flag valid-but-ambiguous constructs. The script automatically falls back to rdflib per file when rapper fails — check the report for `⚠️ rapper failed, parsed with rdflib` notes to identify format mismatches.

Frequently asked questions