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folio-mcp

alea-institute/folio-mcp

MCP server for FOLIO, the Federated Open Legal Information Ontology

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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

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