Skip to content
OntoSkills

MCP With Codex

OntoMCP With Codex

Install

Install the runtime first:

Terminal window
npx ontoskills install mcp

This installs:

~/.ontoskills/bin/ontomcp

Integration Model

Codex-based workflows use the same MCP contract as other local clients:

  • launch ontomcp as a local stdio subprocess
  • point it at the managed ontology home in ~/.ontoskills/ontoskills
  • let the client call the four public tools

The stable executable to register is:

~/.ontoskills/bin/ontomcp
Terminal window
~/.ontoskills/bin/ontomcp --ontology-root ~/.ontoskills/ontoskills

If your Codex client supports environment-based configuration, the equivalent setting is:

Terminal window
ONTOSKILLS_MCP_ONTOLOGY_ROOT=~/.ontoskills/ontoskills

Tools Exposed

  • search_skills
  • get_skill_context
  • evaluate_execution_plan
  • query_epistemic_rules

Notes

  • The MCP server reads compiled .ttl ontologies, not raw SKILL.md
  • If you want custom skills, install the compiler too:
Terminal window
npx ontoskills install core
  • Then compile or import source skills and enable them before expecting Codex to see them through OntoMCP

Practical Rule

Treat Codex integration as a standard local stdio MCP registration whose command points at:

~/.ontoskills/bin/ontomcp

The exact UI or config file shape may vary across Codex builds, but the server command and ontology root remain the same.