MCP with Claude Code

Install

Install the runtime first:

npx ontoskills install mcp

This gives you the managed runtime binary:

~/.ontoskills/bin/ontomcp

Register the server

Fastest bootstrap:

npx ontoskills install mcp --claude

Manual equivalent:

claude mcp add --scope user ontomcp -- \
  ~/.ontoskills/bin/ontomcp

Project-local instead:

npx ontoskills install mcp --claude --project

If you want to force a specific ontology root manually:

claude mcp add --scope user ontomcp -- \
  ~/.ontoskills/bin/ontomcp --ontology-root ~/.ontoskills/ontologies

Verify

claude mcp get ontomcp
claude mcp list

Expected state:

Status: ✓ Connected

What Claude Code can use

Once connected, Claude Code can call:

• ontoskill — unified skill discovery and context retrieval. Pass a skill ID (e.g. pdf) for full context, or a natural language query (e.g. create a pdf document) for BM25 search.

This single tool replaces the previous 5-tool workflow (search, get_skill_context, evaluate_execution_plan, query_epistemic_rules, prefetch_knowledge).

Troubleshooting

Connection fails

Check:

• ~/.ontoskills/bin/ontomcp exists
• ~/.ontoskills/ontologies/ exists
• index.enabled.ttl or compiled .ttl files exist

Ontology not found

Run with an explicit root:

~/.ontoskills/bin/ontomcp --ontology-root ~/.ontoskills/ontologies

Rebuilt binary but Claude still behaves strangely

Remove and re-add the MCP server, or restart Claude Code. A stale background process can keep the old binary alive.