MCP with Codex

Install

Install the runtime first:

npx ontoskills install mcp

This installs:

~/.ontoskills/bin/ontomcp

Fast bootstrap

The recommended setup is:

npx ontoskills install mcp --codex

Manual equivalent:

codex mcp add ontomcp -- ~/.ontoskills/bin/ontomcp

Codex global setup uses the same local stdio command as other clients:

~/.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/ontologies
• let the client call the five public tools

The stable executable to register is:

~/.ontoskills/bin/ontomcp

Recommended runtime command

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

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

ONTOMCP_ONTOLOGY_ROOT=~/.ontoskills/ontologies

Tools exposed

• search_skills
• get_skill_context
• evaluate_execution_plan
• query_epistemic_rules
• search_intents

Notes

• The MCP server reads compiled .ttl ontologies, not raw SKILL.md
• If you want custom skills, install the compiler too:

npx ontoskills install core

• Then compile or import source skills — they are auto-enabled on install for MCP access
• --codex automates Codex global setup only; for repository-local Codex MCP config, ontoskills currently prints manual steps instead of forcing a non-standard config file

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.