MCP Directory

How to add ontomics to Cursor

Give any coding agent instant semantic knowledge of your codebase — one tool call instead of 19, ~20x fewer tokens. Paste the config into ~/.cursor/mcp.json and restart Cursor.

Last updated June 14, 2026 · 36★ · stdio · no auth

Cursor config for ontomics

npm install -g @ontomics/ontomics
{
  "mcpServers": {
    "ontomics": {
      "command": "npx",
      "args": [
        "-y",
        "@ontomics/ontomics",
        "--repo",
        "."
      ]
    }
  }
}

Setup steps

  1. 1Open Cursor → Settings → MCP → Add new MCP server (or edit ~/.cursor/mcp.json directly).
  2. 2Paste the ontomics config below into the "mcpServers" object.
  3. 3Fill in placeholder secrets, then save.
  4. 4Cursor reloads MCP servers automatically — check Settings → MCP for a green status dot.
  5. 5Ask Cursor to use one of ontomics's tools to confirm it's connected.

Before you start

  • A git repository (.git/ directory); non-git directories require --force
  • The ontomics binary, installed via npm (@ontomics/ontomics), Homebrew (EtienneChollet/tap/ontomics), the shell installer, or built from source with cargo
  • Supported source languages: Python, TypeScript, JavaScript, or Rust
  • macOS or Linux

What ontomics can do in Cursor

query_concept

Find all variants, related concepts, and occurrences of a term.

locate_concept

Find the key signatures, classes, and files for a concept.

describe_symbol

Get the signature, docstring, and relationships for a function or class.

trace_concept

Trace how a concept flows through the codebase via call chains.

list_concepts

List the top domain concepts by frequency.

list_conventions

List all detected naming patterns (prefixes, suffixes, conversions).

list_entities

List code entities (classes, functions) filtered by concept, role, or kind.

check_naming

Check an identifier against project conventions; suggests the canonical form.

Security

Runs entirely locally — no API keys and no network calls for indexing (embedding models are downloaded once on first run and cached). Requires a git repository; ontomics refuses to index home, root, or temp directories unless --force is passed.

ontomics + Cursor FAQ

Where is the Cursor config file?

Cursor reads MCP servers from ~/.cursor/mcp.json. Paste the ontomics config there under the "mcpServers" key and restart the client.

Is ontomics safe to use with Cursor?

Runs entirely locally — no API keys and no network calls for indexing (embedding models are downloaded once on first run and cached). Requires a git repository; ontomics refuses to index home, root, or temp directories unless --force is passed.

Does it require any API keys or send my code to a service?

No. The entire pipeline runs locally. The two embedding models (BGE-small and CodeRankEmbed) are downloaded once on first run and cached; indexing makes no API calls.

Which languages are supported?

Python, TypeScript, JavaScript, and Rust, auto-detected from file extensions.

Where is the index stored?

At <repo>/.ontomics/index.db. Subsequent startups load from cache and watch for file changes. Configuration lives in .ontomics/config.toml.

View repo Full ontomics page