Install in Claude Code

OTO is built and tested with Claude Code, and this page installs it there. The skills are Markdown playbooks and the query tools a standard MCP server, so a harness of your choice can load the same files; other harnesses are being tested.

Two things on the machine first: uv, and the engine's command line, which the skills call as oto.

uv tool install "oto-kg @ git+https://github.com/Cynergis/oto"

The registry is a Claude Code marketplace. Adding it gives you the engine plugin and every pack.

/plugin marketplace add Cynergis/oto-registry
/plugin install software-architecture@cynergis

Installing a pack installs the engine plugin oto with it, as a dependency. From then on, in any project Claude Code opens:

• the pack's start skill begins a knowledge project from the installed copy of its ontology, with nothing fetched: oto init --pack "${CLAUDE_PLUGIN_ROOT}", where Claude Code fills in the plugin's directory;
• the engine's ten skills are available: build a knowledge base, design the vocabulary by interview, curate a document or a correction, evaluate against gold questions, and the rest, listed under Skills;
• the query tools kg_entity, kg_neighbors, kg_search, kg_by_type, kg_count, kg_explain, kg_policy, kg_actions and the others are registered as an MCP server for the open project, so the agent asks the graph instead of guessing;
• a session hook runs oto status when a session starts, so the agent knows where the project is before you say anything.

The hook and the MCP server run the engine through uvx on their own; the skills run the oto you installed above. The engine's repository is public, so nothing else is needed.

The engine plugin alone

To have the skills and the query tools without a domain pack:

/plugin install oto@cynergis

Or, from the engine's own repository:

claude --plugin-dir <a checkout of Cynergis/oto>

A private marketplace of your own

Every registry is a marketplace. A company publishes its own ontologies and packs with oto ontology publish and oto pack publish into a repository it controls, then /plugin marketplace add <owner>/<repository> in Claude Code, and oto registry add <url> at a terminal. The catalog for it is one command, oto registry site, and hosts anywhere static.

Updating