folio-mcp 0.4.1

MCP server for FOLIO, the Federated Open Legal Information Ontology

folio-mcp

MCP server for FOLIO, the Federated Open Legal Information Ontology.

FOLIO is an open-source legal ontology with 18,000+ concepts covering areas of law, document types, legal entities, governmental bodies, and more. This MCP server makes the full ontology available to AI agents as searchable, browsable tools.

A public REST API is already available at https://folio.openlegalstandard.org/ with interactive Swagger documentation at /docs. This MCP server wraps the same ontology for native use in AI coding assistants and agent frameworks.

License: MIT (server code) / CC-BY 4.0 (ontology data)

Backends

folio-mcp supports two interchangeable backends:

Mode	Startup	Dependencies	Use case
API (default)	Instant	httpx only	Normal usage — calls the public FOLIO REST API
Local (--local)	~10s	folio-python[search]	Offline use or when mounting inside folio-api

API mode (default)

The server starts instantly and delegates all queries to the public API at https://folio.openlegalstandard.org/. No local ontology loading required.

Local mode

Loads the full FOLIO ontology in-process (~18k classes). Useful for offline work or when embedded in folio-api.

# Install with local dependencies
pip install folio-mcp[local]

# Run in local mode
folio-mcp --local

# Or via environment variable
FOLIO_MCP_LOCAL=1 folio-mcp

Custom API URL

Point to a different FOLIO API instance:

folio-mcp --api-url https://my-folio-instance.example.com

Installation

Claude Code

claude mcp add folio -- uvx folio-mcp

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "folio": {
      "command": "uvx",
      "args": ["folio-mcp"]
    }
  }
}

Cursor

Add to .cursor/mcp.json in your project:

{
  "mcpServers": {
    "folio": {
      "command": "uvx",
      "args": ["folio-mcp"]
    }
  }
}

VS Code

Add to your User Settings (JSON):

{
  "mcp": {
    "servers": {
      "folio": {
        "command": "uvx",
        "args": ["folio-mcp"]
      }
    }
  }
}

Remote (Streamable HTTP)

Connect to the hosted endpoint:

https://folio.openlegalstandard.org/mcp

Manual (pip)

pip install folio-mcp
folio-mcp

Tools (12)

Tool	Description
search_concepts(query, limit=10)	Search concepts by label/name using fuzzy matching
search_definitions(query, limit=10)	Search concepts by definition text
query_concepts(...)	Advanced query with composable text and structural filters
query_properties(...)	Query OWL object properties by label, domain, range
get_concept(iri)	Get full details for a concept by IRI
export_concept(iri, format)	Export a concept as markdown, JSON-LD, or OWL XML
list_branches()	List all 24 taxonomy branches with concept counts
get_taxonomy_branch(branch_name, max_depth)	Get concepts in a taxonomy branch
get_children(iri, max_depth)	Get child concepts
get_parents(iri, max_depth)	Get parent concepts
get_properties()	Get all OWL object properties (relationships)
find_connections(subject_iri, property_name, object_iri)	Find semantic triples

Browse operations return compact summaries (iri, label, definition). Use get_concept(iri) for full details including translations (31% of concepts, 10+ languages), preferred labels, external identifiers, and cross-references.

Prompts (3)

Prompt	Description	Argument
classify-document	Classify a legal document against the FOLIO taxonomy	description
identify-area-of-law	Identify applicable areas of law for a situation	situation
classify-entity	Classify a legal entity (person, org, role)	entity

Each prompt guides the LLM through the correct tool workflow and returns structured output (FOLIO label, IRI, definition, confidence, reasoning).

Resources (3)

Resource URI	Description
folio://branches	Branch names with concept counts (564 bytes)
folio://stats	Ontology statistics — version, class/property counts, license
folio://branch/{name}	Top-level concepts in a specific branch (on-demand)

Taxonomy Branches

The FOLIO ontology is organized into 24 top-level branches:

Branch	Description
actors_players	Parties, roles, and participants in legal matters
areas_of_law	Legal practice areas and specializations
asset_types	Types of assets (real property, intellectual property, etc.)
communication_modalities	Communication channels and methods
currencies	Monetary currencies
data_formats	Data and file formats
document_artifacts	Legal documents, contracts, filings
engagement_terms	Terms of engagement and fee arrangements
events	Legal events and milestones
forum_venues	Courts, tribunals, and dispute resolution venues
governmental_bodies	Government agencies and departments
industries	Industry sectors and classifications
languages	Natural languages
folio_types	FOLIO internal type classifications
legal_authorities	Statutes, regulations, case law
legal_entities	Entity types (corporations, LLCs, trusts, etc.)
locations	Geographic locations and jurisdictions
matter_narratives	Matter descriptions and narratives
matter_narrative_formats	Formats for matter narratives
objectives	Legal objectives and goals
services	Legal services and service types
standards_compatibilities	Standards and compatibility mappings
statuses	Status values for matters, documents, etc.
system_identifiers	System and external identifiers

Development

# Clone and install
git clone https://github.com/alea-institute/folio-mcp.git
cd folio-mcp
uv sync

# Run tests (requires folio-python for local backend tests)
uv sync --extra local
uv run pytest tests/

# Run with MCP Inspector
uv run mcp dev folio_mcp/server.py

# Run locally for Claude Code
claude mcp add folio-dev -- uv run --directory /path/to/folio-mcp folio-mcp

Links

• FOLIO Website
• FOLIO REST API — public API for direct HTTP access
• FOLIO API Docs (Swagger) — interactive API documentation
• folio-python — Python client library
• folio-api — REST API server
• ALEA Institute