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

folio-mcp

folio-mcp

Backends

API mode (default)

Local mode

Custom API URL

Installation

Claude Code

Claude Desktop

Cursor

VS Code

Remote (Streamable HTTP)

Manual (pip)

Tools (12)

Prompts (3)

Resources (3)

Taxonomy Branches

Development

Links

Latest Blog Posts

MCP directory API