CourtListener

Official34 toolsLive

by Vaquill-AI · Python

MCP for CourtListener: US federal and state opinions, dockets, judges, plus eCFR regulations.

CourtListener MCP Server (io.github.Vaquill-AI/courtlistener-mcp)

This Model Context Protocol (MCP) server exposes the CourtListener legal database to AI assistants. It provides access to US federal and state court opinions, dockets, RECAP filings, PACER data, oral arguments, and judges, as well as eCFR regulations. Data is served via the official CourtListener API v4.

🛠️ Key Features

MCP server for CourtListener
Access to federal and state opinions
Access to dockets and RECAP filings
Access to PACER data and oral arguments
Access to judges
Access to Electronic Code of Federal Regulations (eCFR) via CourtListener API v4
34 tools

🚀 Use Cases

Legal research on US case law and related records
Retrieving docket information and court activity
Finding judge information linked to CourtListener sources
Checking eCFR regulations through the same API

⚡ Developer Benefits

MCP-compatible integration for MCP clients
Uses the official CourtListener API v4
Supports workflows in Claude Desktop, Claude Code, Cursor, VS Code, Windsurf, ChatGPT Desktop

⚠️ Limitations

Described as supporting CourtListener data and eCFR through CourtListener API v4 only
Scope limited to the provided CourtListener legal database categories

Topics

case-lawclaudecourtlistenerlegal-ailegal-researchlegaltechmcpmcp-servermodel-context-protocolpacerus-law

Captured live from the server via tools/list.

status

Check the status of the CourtListener MCP server. Returns: A dictionary containing server status, system metrics, and service information.

Parameters

No parameters.

Raw schema

{
  "type": "object",
  "properties": {},
  "additionalProperties": false
}

search_opinions

Search case law opinion clusters with nested Opinion documents in CourtListener.

Parameters11

q	string	required	Search query for full text of opinions
court	any	optional	Court ID filter (e.g., 'scotus', 'ca9')
case_name	any	optional	Filter by case name
judge	any	optional	Filter by judge name
filed_after	any	optional	Only show opinions filed after this date (YYYY-MM-DD)
filed_before	any	optional	Only show opinions filed before this date (YYYY-MM-DD)
cited_gt	any	optional	Minimum number of times opinion has been cited
cited_lt	any	optional	Maximum number of times opinion has been cited
order_by	string	optional	Sort by 'score desc', 'dateFiled desc', or 'dateFiled asc'
limit	integer	optional	Max results from this page (upper bound; CL pages ~20)
cursor	any	optional	Pagination cursor from a prior response's next_cursor

Raw schema

{
  "type": "object",
  "properties": {
    "q": {
      "description": "Search query for full text of opinions",
      "type": "string"
    },
    "court": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Court ID filter (e.g., 'scotus', 'ca9')"
    },
    "case_name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by case name"
    },
    "judge": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by judge name"
    },
    "filed_after": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Only show opinions filed after this date (YYYY-MM-DD)"
    },
    "filed_before": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Only show opinions filed before this date (YYYY-MM-DD)"
    },
    "cited_gt": {
      "anyOf": [
        {
          "minimum": 0,
          "type": "integer"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Minimum number of times opinion has been cited"
    },
    "cited_lt": {
      "anyOf": [
        {
          "minimum": 0,
          "type": "integer"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Maximum number of times opinion has been cited"
    },
    "order_by": {
      "default": "score desc",
      "description": "Sort by 'score desc', 'dateFiled desc', or 'dateFiled asc'",
      "type": "string"
    },
    "limit": {
      "default": 20,
      "description": "Max results from this page (upper bound; CL pages ~20)",
      "maximum": 100,
      "minimum": 1,
      "type": "integer"
    },
    "cursor": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Pagination cursor from a prior response's next_cursor"
    }
  },
  "required": [
    "q"
  ],
  "additionalProperties": false
}

search_dockets

Search federal cases (dockets) from PACER in CourtListener.

Parameters10

q	string	required	Search query for docket text
court	any	optional	Court ID filter (e.g., 'scotus', 'ca9')
case_name	any	optional	Filter by case name
docket_number	any	optional	Specific docket number to search for
date_filed_after	any	optional	Filter dockets filed after this date (YYYY-MM-DD)
date_filed_before	any	optional	Filter dockets filed before this date (YYYY-MM-DD)
party_name	any	optional	Filter by party name
order_by	string	optional	Sort by 'score desc', 'dateFiled desc', or 'dateFiled asc'
limit	integer	optional	Max results from this page (upper bound; CL pages ~20)
cursor	any	optional	Pagination cursor from a prior response's next_cursor

Raw schema

{
  "type": "object",
  "properties": {
    "q": {
      "description": "Search query for docket text",
      "type": "string"
    },
    "court": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Court ID filter (e.g., 'scotus', 'ca9')"
    },
    "case_name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by case name"
    },
    "docket_number": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Specific docket number to search for"
    },
    "date_filed_after": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter dockets filed after this date (YYYY-MM-DD)"
    },
    "date_filed_before": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter dockets filed before this date (YYYY-MM-DD)"
    },
    "party_name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by party name"
    },
    "order_by": {
      "default": "score desc",
      "description": "Sort by 'score desc', 'dateFiled desc', or 'dateFiled asc'",
      "type": "string"
    },
    "limit": {
      "default": 20,
      "description": "Max results from this page (upper bound; CL pages ~20)",
      "maximum": 100,
      "minimum": 1,
      "type": "integer"
    },
    "cursor": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Pagination cursor from a prior response's next_cursor"
    }
  },
  "required": [
    "q"
  ],
  "additionalProperties": false
}

search_dockets_with_documents

Search federal cases (dockets) with up to three nested documents. If there are more than three matching documents, the more_docs field will be true.

Parameters10

q	string	required	Search query for federal cases
court	any	optional	Court ID filter (e.g., 'scotus', 'ca9')
case_name	any	optional	Filter by case name
docket_number	any	optional	Specific docket number to search for
date_filed_after	any	optional	Filter dockets filed after this date (YYYY-MM-DD)
date_filed_before	any	optional	Filter dockets filed before this date (YYYY-MM-DD)
party_name	any	optional	Filter by party name
order_by	string	optional	Sort by 'score desc', 'dateFiled desc', or 'dateFiled asc'
limit	integer	optional	Max results from this page (upper bound; CL pages ~20)
cursor	any	optional	Pagination cursor from a prior response's next_cursor

Raw schema

{
  "type": "object",
  "properties": {
    "q": {
      "description": "Search query for federal cases",
      "type": "string"
    },
    "court": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Court ID filter (e.g., 'scotus', 'ca9')"
    },
    "case_name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by case name"
    },
    "docket_number": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Specific docket number to search for"
    },
    "date_filed_after": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter dockets filed after this date (YYYY-MM-DD)"
    },
    "date_filed_before": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter dockets filed before this date (YYYY-MM-DD)"
    },
    "party_name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by party name"
    },
    "order_by": {
      "default": "score desc",
      "description": "Sort by 'score desc', 'dateFiled desc', or 'dateFiled asc'",
      "type": "string"
    },
    "limit": {
      "default": 20,
      "description": "Max results from this page (upper bound; CL pages ~20)",
      "maximum": 100,
      "minimum": 1,
      "type": "integer"
    },
    "cursor": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Pagination cursor from a prior response's next_cursor"
    }
  },
  "required": [
    "q"
  ],
  "additionalProperties": false
}

search_recap_documents

Search federal filing documents from PACER in the RECAP archive.

Parameters12

q	string	required	Search query for RECAP filing documents
court	any	optional	Court ID filter (e.g., 'scotus', 'ca9')
case_name	any	optional	Filter by case name
docket_number	any	optional	Specific docket number to search for
document_number	any	optional	Specific document number to search for
attachment_number	any	optional	Specific attachment number to search for
filed_after	any	optional	Filter documents filed after this date (YYYY-MM-DD)
filed_before	any	optional	Filter documents filed before this date (YYYY-MM-DD)
party_name	any	optional	Filter by party name
order_by	string	optional	Sort by 'score desc', 'dateFiled desc', or 'dateFiled asc'
limit	integer	optional	Max results from this page (upper bound; CL pages ~20)
cursor	any	optional	Pagination cursor from a prior response's next_cursor

Raw schema

{
  "type": "object",
  "properties": {
    "q": {
      "description": "Search query for RECAP filing documents",
      "type": "string"
    },
    "court": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Court ID filter (e.g., 'scotus', 'ca9')"
    },
    "case_name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by case name"
    },
    "docket_number": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Specific docket number to search for"
    },
    "document_number": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Specific document number to search for"
    },
    "attachment_number": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Specific attachment number to search for"
    },
    "filed_after": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter documents filed after this date (YYYY-MM-DD)"
    },
    "filed_before": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter documents filed before this date (YYYY-MM-DD)"
    },
    "party_name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by party name"
    },
    "order_by": {
      "default": "score desc",
      "description": "Sort by 'score desc', 'dateFiled desc', or 'dateFiled asc'",
      "type": "string"
    },
    "limit": {
      "default": 20,
      "description": "Max results from this page (upper bound; CL pages ~20)",
      "maximum": 100,
      "minimum": 1,
      "type": "integer"
    },
    "cursor": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Pagination cursor from a prior response's next_cursor"
    }
  },
  "required": [
    "q"
  ],
  "additionalProperties": false
}

search_audio

Search oral argument audio recordings in CourtListener.

Parameters9

q	string	required	Search query for oral argument audio
court	any	optional	Court ID filter (e.g., 'scotus', 'ca9')
case_name	any	optional	Filter by case name
judge	any	optional	Filter by judge name
argued_after	any	optional	Filter arguments after this date (YYYY-MM-DD)
argued_before	any	optional	Filter arguments before this date (YYYY-MM-DD)
order_by	string	optional	Sort by 'score desc', 'dateArgued desc', or 'dateArgued asc'
limit	integer	optional	Max results from this page (upper bound; CL pages ~20)
cursor	any	optional	Pagination cursor from a prior response's next_cursor

Raw schema

{
  "type": "object",
  "properties": {
    "q": {
      "description": "Search query for oral argument audio",
      "type": "string"
    },
    "court": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Court ID filter (e.g., 'scotus', 'ca9')"
    },
    "case_name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by case name"
    },
    "judge": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by judge name"
    },
    "argued_after": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter arguments after this date (YYYY-MM-DD)"
    },
    "argued_before": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter arguments before this date (YYYY-MM-DD)"
    },
    "order_by": {
      "default": "score desc",
      "description": "Sort by 'score desc', 'dateArgued desc', or 'dateArgued asc'",
      "type": "string"
    },
    "limit": {
      "default": 20,
      "description": "Max results from this page (upper bound; CL pages ~20)",
      "maximum": 100,
      "minimum": 1,
      "type": "integer"
    },
    "cursor": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Pagination cursor from a prior response's next_cursor"
    }
  },
  "required": [
    "q"
  ],
  "additionalProperties": false
}

search_people

Search judges and legal professionals in the CourtListener database.

Parameters10

q	string	required	Search query for judges and legal professionals
name	any	optional	Filter by person's name
position_type	any	optional	Filter by position type (e.g., 'jud' for judge)
political_affiliation	any	optional	Filter by political affiliation
school	any	optional	Filter by school attended
appointed_by	any	optional	Filter by appointing authority
selection_method	any	optional	Filter by selection method
order_by	string	optional	Sort by 'score desc' or 'name asc'
limit	integer	optional	Max results from this page (upper bound; CL pages ~20)
cursor	any	optional	Pagination cursor from a prior response's next_cursor

Raw schema

{
  "type": "object",
  "properties": {
    "q": {
      "description": "Search query for judges and legal professionals",
      "type": "string"
    },
    "name": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by person's name"
    },
    "position_type": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by position type (e.g., 'jud' for judge)"
    },
    "political_affiliation": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by political affiliation"
    },
    "school": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by school attended"
    },
    "appointed_by": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by appointing authority"
    },
    "selection_method": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Filter by selection method"
    },
    "order_by": {
      "default": "score desc",
      "description": "Sort by 'score desc' or 'name asc'",
      "type": "string"
    },
    "limit": {
      "default": 20,
      "description": "Max results from this page (upper bound; CL pages ~20)",
      "maximum": 100,
      "minimum": 1,
      "type": "integer"
    },
    "cursor": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Pagination cursor from a prior response's next_cursor"
    }
  },
  "required": [
    "q"
  ],
  "additionalProperties": false
}

get_opinion

Get a specific court opinion by ID from CourtListener.

Parameters1

opinion_id

string

required

The opinion ID to retrieve

Raw schema

{
  "type": "object",
  "properties": {
    "opinion_id": {
      "description": "The opinion ID to retrieve",
      "type": "string"
    }
  },
  "required": [
    "opinion_id"
  ],
  "additionalProperties": false
}

get_docket

Get a specific court docket by ID from CourtListener.

Parameters1

docket_id

string

required

The docket ID to retrieve

Raw schema

{
  "type": "object",
  "properties": {
    "docket_id": {
      "description": "The docket ID to retrieve",
      "type": "string"
    }
  },
  "required": [
    "docket_id"
  ],
  "additionalProperties": false
}

get_audio

Get oral argument audio information by ID from CourtListener.

Parameters1

audio_id

string

required

The audio recording ID to retrieve

Raw schema

{
  "type": "object",
  "properties": {
    "audio_id": {
      "description": "The audio recording ID to retrieve",
      "type": "string"
    }
  },
  "required": [
    "audio_id"
  ],
  "additionalProperties": false
}

get_cluster

Get an opinion cluster by ID from CourtListener.

Parameters1

cluster_id

string

required

The opinion cluster ID to retrieve

Raw schema

{
  "type": "object",
  "properties": {
    "cluster_id": {
      "description": "The opinion cluster ID to retrieve",
      "type": "string"
    }
  },
  "required": [
    "cluster_id"
  ],
  "additionalProperties": false
}

get_person

Get judge or legal professional information by ID from CourtListener.

Parameters1

person_id

string

required

The person (judge) ID to retrieve

Raw schema

{
  "type": "object",
  "properties": {
    "person_id": {
      "description": "The person (judge) ID to retrieve",
      "type": "string"
    }
  },
  "required": [
    "person_id"
  ],
  "additionalProperties": false
}

get_court

Get court information by ID from CourtListener.

Parameters1

court_id

string

required

The court ID to retrieve (e.g., 'scotus', 'ca9')

Raw schema

{
  "type": "object",
  "properties": {
    "court_id": {
      "description": "The court ID to retrieve (e.g., 'scotus', 'ca9')",
      "type": "string"
    }
  },
  "required": [
    "court_id"
  ],
  "additionalProperties": false
}

citation_lookup_citation

Look up a legal citation to find the opinion it references in CourtListener. This tool accepts various citation formats including: - U.S. Reporter citations (e.g., "410 U.S. 113") - Federal Reporter citations (e.g., "123 F.3d 456") - WestLaw citations (e.g., "2023 WL 12345") - State reporter citations

Parameters1

citation

string

required

The citation to look up (e.g., '410 U.S. 113', '2023 WL 12345')

Raw schema

{
  "type": "object",
  "properties": {
    "citation": {
      "description": "The citation to look up (e.g., '410 U.S. 113', '2023 WL 12345')",
      "type": "string"
    }
  },
  "required": [
    "citation"
  ],
  "additionalProperties": false
}

citation_batch_lookup_citations

Look up multiple legal citations in a single request. This is more efficient than making individual requests for each citation. Accepts up to 100 citations at once.

Parameters1

citations

array

required

List of citations to look up (max 100)

Raw schema

{
  "type": "object",
  "properties": {
    "citations": {
      "description": "List of citations to look up (max 100)",
      "items": {
        "type": "string"
      },
      "maxItems": 100,
      "minItems": 1,
      "type": "array"
    }
  },
  "required": [
    "citations"
  ],
  "additionalProperties": false
}

citation_verify_citation_format

Verify if a citation string is in a valid format using citeurl's advanced parsing. This tool performs validation using citeurl's comprehensive citation templates to check if a citation appears to be in a recognized legal citation format. This is much more accurate than simple regex matching. Returns information about the citation format and any detected issues.

Parameters1

citation

string

required

The citation to verify

Raw schema

{
  "type": "object",
  "properties": {
    "citation": {
      "description": "The citation to verify",
      "type": "string"
    }
  },
  "required": [
    "citation"
  ],
  "additionalProperties": false
}

citation_parse_citation_with_citeurl

Parse a legal citation using citeurl's advanced citation recognition. This tool uses the citeurl library to parse legal citations and extract structured information including tokens, normalized format, and URL generation. Returns detailed information about the citation including: - Recognized citation format and source - Extracted tokens (volume, reporter, page, etc.) - Generated URL if available - Normalized citation text

Parameters2

citation	string	required	The citation to parse (e.g., '410 U.S. 113', '42 USC § 1988')
broad	boolean	optional	Use broad matching for more flexible parsing

Raw schema

{
  "type": "object",
  "properties": {
    "citation": {
      "description": "The citation to parse (e.g., '410 U.S. 113', '42 USC § 1988')",
      "type": "string"
    },
    "broad": {
      "default": true,
      "description": "Use broad matching for more flexible parsing",
      "type": "boolean"
    }
  },
  "required": [
    "citation"
  ],
  "additionalProperties": false
}

citation_extract_citations_from_text

Extract all legal citations from a block of text using citeurl. This tool finds and parses all legal citations within a given text, including both long-form and short-form citations (like 'id.' references).

Parameters1

text

string

required

Text containing legal citations to extract

Raw schema

{
  "type": "object",
  "properties": {
    "text": {
      "description": "Text containing legal citations to extract",
      "type": "string"
    }
  },
  "required": [
    "text"
  ],
  "additionalProperties": false
}

citation_enhanced_citation_lookup

Enhanced citation lookup combining citeurl parsing with CourtListener data. This tool first uses citeurl to parse and validate the citation format, then optionally queries the CourtListener API for additional case information.

Parameters2

citation	string	required	The citation to look up and analyze
include_courtlistener	boolean	optional	Whether to also perform CourtListener API lookup

Raw schema

{
  "type": "object",
  "properties": {
    "citation": {
      "description": "The citation to look up and analyze",
      "type": "string"
    },
    "include_courtlistener": {
      "default": true,
      "description": "Whether to also perform CourtListener API lookup",
      "type": "boolean"
    }
  },
  "required": [
    "citation"
  ],
  "additionalProperties": false
}

ecfr_list_titles

List all 50 CFR titles with their latest amended/issue dates and status.

Parameters

No parameters.

Raw schema

{
  "type": "object",
  "properties": {},
  "additionalProperties": false
}

ecfr_get_title_versions

List the available content versions (issue dates) for one CFR title.

Parameters1

title

integer

required

CFR title number (1-50)

Raw schema

{
  "type": "object",
  "properties": {
    "title": {
      "description": "CFR title number (1-50)",
      "maximum": 50,
      "minimum": 1,
      "type": "integer"
    }
  },
  "required": [
    "title"
  ],
  "additionalProperties": false
}

ecfr_get_title_structure

Get the full hierarchical structure (title -> section) of a CFR title on a date.

Parameters2

title	integer	required	CFR title number (1-50)
date	string	required	Snapshot date (YYYY-MM-DD)

Raw schema

{
  "type": "object",
  "properties": {
    "title": {
      "description": "CFR title number (1-50)",
      "maximum": 50,
      "minimum": 1,
      "type": "integer"
    },
    "date": {
      "description": "Snapshot date (YYYY-MM-DD)",
      "type": "string"
    }
  },
  "required": [
    "title",
    "date"
  ],
  "additionalProperties": false
}

ecfr_get_ancestry

Get the ancestry chain (title -> ... -> node) for a CFR node on a date.

Parameters4

title	integer	required	CFR title number (1-50)
date	string	required	Snapshot date (YYYY-MM-DD)
part	any	optional	Restrict to a part, e.g. '75'
section	any	optional	Restrict to a section, e.g. '75.1'

Raw schema

{
  "type": "object",
  "properties": {
    "title": {
      "description": "CFR title number (1-50)",
      "maximum": 50,
      "minimum": 1,
      "type": "integer"
    },
    "date": {
      "description": "Snapshot date (YYYY-MM-DD)",
      "type": "string"
    },
    "part": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Restrict to a part, e.g. '75'"
    },
    "section": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Restrict to a section, e.g. '75.1'"
    }
  },
  "required": [
    "title",
    "date"
  ],
  "additionalProperties": false
}

ecfr_get_source_xml

Fetch the source regulation TEXT (XML) for a CFR node on a snapshot date. Pass a part or section to scope the request. Fetching an entire large title at once can time out on the eCFR side, so narrowing is strongly recommended. Returns the raw XML under ``content_xml``.

Parameters9

title	integer	required	CFR title number (1-50)
date	string	required	Snapshot date (YYYY-MM-DD)
part	any	optional	Part to fetch, e.g. '75'. STRONGLY recommended: whole-title fetches can time out.
section	any	optional	Section, e.g. '75.1'
subtitle	any	optional	Subtitle, e.g. 'A'
chapter	any	optional	Chapter, e.g. 'I'
subchapter	any	optional	Subchapter, e.g. 'B'
subpart	any	optional	Subpart, e.g. 'C'
appendix	any	optional	Appendix identifier

Raw schema

{
  "type": "object",
  "properties": {
    "title": {
      "description": "CFR title number (1-50)",
      "maximum": 50,
      "minimum": 1,
      "type": "integer"
    },
    "date": {
      "description": "Snapshot date (YYYY-MM-DD)",
      "type": "string"
    },
    "part": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Part to fetch, e.g. '75'. STRONGLY recommended: whole-title fetches can time out."
    },
    "section": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Section, e.g. '75.1'"
    },
    "subtitle": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Subtitle, e.g. 'A'"
    },
    "chapter": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Chapter, e.g. 'I'"
    },
    "subchapter": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Subchapter, e.g. 'B'"
    },
    "subpart": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Subpart, e.g. 'C'"
    },
    "appendix": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Appendix identifier"
    }
  },
  "required": [
    "title",
    "date"
  ],
  "additionalProperties": false
}

ecfr_list_agencies

List all agencies that appear in the CFR, with their title/chapter references.

Parameters

No parameters.

Raw schema

{
  "type": "object",
  "properties": {},
  "additionalProperties": false
}

ecfr_list_all_corrections

List CFR corrections, optionally filtered by title and/or effective date.

Parameters2

title	any	optional	Restrict to a CFR title number
date	any	optional	Corrections in effect on this date (YYYY-MM-DD)

Raw schema

{
  "type": "object",
  "properties": {
    "title": {
      "anyOf": [
        {
          "maximum": 50,
          "minimum": 1,
          "type": "integer"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Restrict to a CFR title number"
    },
    "date": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Corrections in effect on this date (YYYY-MM-DD)"
    }
  },
  "additionalProperties": false
}

ecfr_list_corrections_by_title

List all corrections for a single CFR title.

Parameters1

title

integer

required

CFR title number (1-50)

Raw schema

{
  "type": "object",
  "properties": {
    "title": {
      "description": "CFR title number (1-50)",
      "maximum": 50,
      "minimum": 1,
      "type": "integer"
    }
  },
  "required": [
    "title"
  ],
  "additionalProperties": false
}

ecfr_search_regulations

Full-text search over federal regulations, returning matching sections with hierarchy.

Parameters7

query	string	required	Full-text search query over the CFR
title	any	optional	Restrict to a CFR title number
agency_slugs	any	optional	Restrict to one or more agency slugs (from list_agencies)
date	any	optional	Search the CFR as of this date (YYYY-MM-DD)
per_page	integer	optional	Results per page (max 20)
page	integer	optional	Page number
order	any	optional	Sort order: 'relevance', 'hierarchy', 'newest_first', 'oldest_first'

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "description": "Full-text search query over the CFR",
      "type": "string"
    },
    "title": {
      "anyOf": [
        {
          "maximum": 50,
          "minimum": 1,
          "type": "integer"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Restrict to a CFR title number"
    },
    "agency_slugs": {
      "anyOf": [
        {
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Restrict to one or more agency slugs (from list_agencies)"
    },
    "date": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Search the CFR as of this date (YYYY-MM-DD)"
    },
    "per_page": {
      "default": 20,
      "description": "Results per page (max 20)",
      "maximum": 20,
      "minimum": 1,
      "type": "integer"
    },
    "page": {
      "default": 1,
      "description": "Page number",
      "minimum": 1,
      "type": "integer"
    },
    "order": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Sort order: 'relevance', 'hierarchy', 'newest_first', 'oldest_first'"
    }
  },
  "required": [
    "query"
  ],
  "additionalProperties": false
}

ecfr_get_search_count

Get the total number of CFR sections matching a search query.

Parameters4

query	string	required	Full-text search query over the CFR
title	any	optional	Restrict to a title
agency_slugs	any	optional	Restrict to agency slugs
date	any	optional	As-of date (YYYY-MM-DD)

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "description": "Full-text search query over the CFR",
      "type": "string"
    },
    "title": {
      "anyOf": [
        {
          "maximum": 50,
          "minimum": 1,
          "type": "integer"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Restrict to a title"
    },
    "agency_slugs": {
      "anyOf": [
        {
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Restrict to agency slugs"
    },
    "date": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "As-of date (YYYY-MM-DD)"
    }
  },
  "required": [
    "query"
  ],
  "additionalProperties": false
}

ecfr_get_search_summary

Get summary details (counts + metadata) for a CFR search query.

Parameters4

query	string	required	Full-text search query over the CFR
title	any	optional	Restrict to a title
agency_slugs	any	optional	Restrict to agency slugs
date	any	optional	As-of date (YYYY-MM-DD)

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "description": "Full-text search query over the CFR",
      "type": "string"
    },
    "title": {
      "anyOf": [
        {
          "maximum": 50,
          "minimum": 1,
          "type": "integer"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Restrict to a title"
    },
    "agency_slugs": {
      "anyOf": [
        {
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "Restrict to agency slugs"
    },
    "date": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "As-of date (YYYY-MM-DD)"
    }
  },
  "required": [
    "query"
  ],
  "additionalProperties": false
}

ecfr_get_title_search_counts

Get search result counts broken down by CFR title.

Parameters2

query	string	required	Full-text search query over the CFR
date	any	optional	As-of date (YYYY-MM-DD)

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "description": "Full-text search query over the CFR",
      "type": "string"
    },
    "date": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "As-of date (YYYY-MM-DD)"
    }
  },
  "required": [
    "query"
  ],
  "additionalProperties": false
}

ecfr_get_daily_search_counts

Get search result counts broken down by date (daily histogram).

Parameters2

query	string	required	Full-text search query over the CFR
date	any	optional	As-of date (YYYY-MM-DD)

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "description": "Full-text search query over the CFR",
      "type": "string"
    },
    "date": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "As-of date (YYYY-MM-DD)"
    }
  },
  "required": [
    "query"
  ],
  "additionalProperties": false
}

ecfr_get_hierarchy_search_counts

Get search result counts distributed across the CFR hierarchy.

Parameters2

query	string	required	Full-text search query over the CFR
date	any	optional	As-of date (YYYY-MM-DD)

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "description": "Full-text search query over the CFR",
      "type": "string"
    },
    "date": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "null"
        }
      ],
      "default": null,
      "description": "As-of date (YYYY-MM-DD)"
    }
  },
  "required": [
    "query"
  ],
  "additionalProperties": false
}

ecfr_get_search_suggestions

Get search-term suggestions for a partial CFR query.

Parameters1

query

string

required

Partial query to get suggestions for

Raw schema

{
  "type": "object",
  "properties": {
    "query": {
      "description": "Partial query to get suggestions for",
      "type": "string"
    }
  },
  "required": [
    "query"
  ],
  "additionalProperties": false
}

README.md8 KBView on GitHub

CourtListener MCP Server

A Model Context Protocol server that gives AI assistants access to the CourtListener legal database (US federal + state court opinions, dockets, RECAP filings, PACER data, oral arguments, judges) and the Electronic Code of Federal Regulations via the official CourtListener API v4.

Use it with Claude Desktop, Claude Code, Cursor, VS Code, Windsurf, ChatGPT Desktop, or any MCP-compatible client.

Forked from Travis-Prall/court-listener-mcp. This fork adds a hosted endpoint, bring-your-own-key (BYOK) auth, a /health route, Dockerfile hardening, a full eCFR (federal regulations) tool suite, cursor pagination, per-client rate limiting, and read-only tool annotations. See the changelog for details.

When to use this vs. the official server

Free Law Project (who run CourtListener) host an official MCP at https://mcp.courtlistener.com/ (OAuth, free with any CourtListener account) - see their announcement. Prefer it if you want OAuth and the broadest CourtListener coverage. Use this server if you want: eCFR federal-regulations tools (the official server has none), simple BYOK header auth (no OAuth dance), or a self-hosted/embeddable Python server. The two are complementary.

Use the hosted endpoint (no install)

The Vaquill team runs a public instance for the community:

code

https://courtlistener-mcp.vaquill.ai/mcp/

You bring your own free CourtListener token from courtlistener.com/help/api/rest/, the server forwards it. We never see or store your key.

Claude Desktop / Claude Code

~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

json

{
  "mcpServers": {
    "courtlistener": {
      "url": "https://courtlistener-mcp.vaquill.ai/mcp/",
      "headers": {
        "X-CourtListener-Token": "YOUR_COURTLISTENER_TOKEN"
      }
    }
  }
}

Cursor

.cursor/mcp.json:

json

{
  "mcpServers": {
    "courtlistener": {
      "url": "https://courtlistener-mcp.vaquill.ai/mcp/",
      "headers": { "X-CourtListener-Token": "YOUR_COURTLISTENER_TOKEN" }
    }
  }
}

VS Code (GitHub Copilot Chat)

.vscode/mcp.json:

json

{
  "servers": {
    "courtlistener": {
      "type": "http",
      "url": "https://courtlistener-mcp.vaquill.ai/mcp/",
      "headers": { "X-CourtListener-Token": "YOUR_COURTLISTENER_TOKEN" }
    }
  }
}

Claude Web (custom connector)

Settings → Connectors → Add custom connector → paste the URL and add X-CourtListener-Token as a header. Workspace owners only.

Windsurf, Continue, etc.

Any client that supports MCP streamable HTTP with custom headers works. For stdio-only clients, run the server locally (see below) or proxy with mcp-remote.

Tools

34 tools across 4 groups (each group is namespaced). All are read-only.

Group	Tools
Search (CourtListener)	`search_opinions`, `search_dockets`, `search_dockets_with_documents`, `search_recap_documents`, `search_audio`, `search_people`
Get (CourtListener)	`get_opinion`, `get_docket`, `get_audio`, `get_court`, `get_person`, `get_cluster`
Citation	`citation_lookup_citation`, `citation_batch_lookup_citations`, `citation_verify_citation_format`, `citation_parse_citation_with_citeurl`, `citation_extract_citations_from_text`, `citation_enhanced_citation_lookup`
eCFR (federal regulations)	`ecfr_list_titles`, `ecfr_get_title_versions`, `ecfr_get_title_structure`, `ecfr_get_ancestry`, `ecfr_get_source_xml`, `ecfr_list_agencies`, `ecfr_list_all_corrections`, `ecfr_list_corrections_by_title`, `ecfr_search_regulations`, `ecfr_get_search_count`, `ecfr_get_search_summary`, `ecfr_get_title_search_counts`, `ecfr_get_daily_search_counts`, `ecfr_get_hierarchy_search_counts`, `ecfr_get_search_suggestions`
System	`status`

Search tools accept a cursor param and return a next_cursor for pagination. See app/README.md for full parameter details.

Authentication

Two modes, in priority order:

Per-request header (BYOK) — preferred for hosted / shared deployments. Send the user's CourtListener key on every MCP request:
- X-CourtListener-Token: <key> (preferred), or
- Authorization: Token <key> (CourtListener's native scheme — only works if the MCP server itself isn't already gated by Authorization).
Server env fallback — set COURT_LISTENER_API_KEY on the server. Used when no per-request header is supplied. Leave unset on public instances to force BYOK and avoid burning the operator's quota.

If neither is provided, tools return a ValueError with a clear message.

Self-host

Docker

bash

git clone https://github.com/Vaquill-AI/courtlistener-mcp.git
cd courtlistener-mcp
cp .env.example .env  # optionally set COURT_LISTENER_API_KEY for single-tenant
docker compose up -d
# server at http://localhost:8000/mcp/

Python (uv)

bash

uv sync
uv run python -m app --transport http

Stdio (local CLI integration)

bash

uv run python -m app --transport stdio

Add to Claude Desktop:

json

{
  "mcpServers": {
    "courtlistener-local": {
      "command": "uv",
      "args": ["run", "--directory", "/abs/path/to/courtlistener-mcp", "python", "-m", "app", "--transport", "stdio"],
      "env": { "COURT_LISTENER_API_KEY": "your_token" }
    }
  }
}

Configuration

Var	Required	Default	Notes
`COURT_LISTENER_API_KEY`	Optional*	—	Fallback when no per-request header. Leave unset on public servers.
`COURTLISTENER_BASE_URL`	No	`https://www.courtlistener.com/api/rest/v4/`
`COURTLISTENER_TIMEOUT`	No	`30`	seconds
`MCP_TRANSPORT`	No	`stdio`	`stdio` \| `http` \| `sse`
`MCP_PORT`	No	`8000`	http/sse only
`HOST`	No	`0.0.0.0`	http/sse only
`ECFR_BASE_URL`	No	`https://www.ecfr.gov`	eCFR API base (no key required)
`RATE_LIMIT_ENABLED`	No	`true`	Per-client MCP rate limiting
`RATE_LIMIT_RPS`	No	`15`	Max requests/sec per client
`RATE_LIMIT_BURST`	No	`40`	Burst capacity per client

* Required only if running in single-tenant mode without BYOK.

Health check

bash

curl https://courtlistener-mcp.vaquill.ai/health
# {"status":"healthy","service":"courtlistener-mcp","version":"..."}

Development

bash

uv sync --dev
uv run pytest
uv run ruff format . && uv run ruff check .
uv run mypy app/

Changelog

0.2.0

Added a full eCFR (federal regulations) tool suite (15 tools): titles, structure, versions, ancestry, source XML, agencies, corrections, and full-text regulation search + analytics. This is the differentiator over CourtListener-only servers.
Fixed a validation crash: optional search filters are now nullable (str | None), so clients that send explicit JSON null no longer get a ValidationError (previously broke search_dockets / search_recap_documents).
Real pagination: removed the no-op hit param; search tools now honor limit and expose a next_cursor token plus an input cursor.
Read-only tool annotations on all tools (better client UX, no write prompts).
Per-client rate limiting middleware (configurable, on by default).
Migrated import_server → mount (FastMCP 3), fixed the API-key env-var alias, refreshed project metadata, and got the test suite green (unit tests mocked; live-API tests gated behind RUN_INTEGRATION=1).

Credits & License

Original implementation: Travis-Prall/court-listener-mcp
Hosted by: Vaquill — courtlistener-mcp.vaquill.ai
License: MIT (see LICENSE)

CourtListener data is provided by the Free Law Project under their respective terms. eCFR data is from ecfr.gov.

Community

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Install

Tools (34)

statussearch_opinionssearch_docketssearch_dockets_with_documentssearch_recap_documentssearch_audiosearch_peopleget_opinion

Remote endpoint

Streamable HTTP

Hosted server - connect over the network, no local install.

url

https://courtlistener-mcp.vaquill.ai/mcp/

Add to VS Code Add to Cursor

claude_desktop_config.json

json

{
  "mcpServers": {
    "courtlistener-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://courtlistener-mcp.vaquill.ai/mcp/"
      ]
    }
  }
}

Desktop config is stdio-only; this bridges via mcp-remote. Native remote: Settings > Connectors.

CourtListener MCP Server (io.github.Vaquill-AI/courtlistener-mcp)

🛠️ Key Features

🚀 Use Cases

⚡ Developer Benefits

⚠️ Limitations

Topics

status

search_opinions

search_dockets

search_dockets_with_documents

search_recap_documents

search_audio

search_people

get_opinion

get_docket

get_audio

get_cluster

get_person

get_court

citation_lookup_citation

citation_batch_lookup_citations

citation_verify_citation_format

citation_parse_citation_with_citeurl

citation_extract_citations_from_text

citation_enhanced_citation_lookup

ecfr_list_titles

ecfr_get_title_versions

ecfr_get_title_structure

ecfr_get_ancestry

ecfr_get_source_xml

ecfr_list_agencies

ecfr_list_all_corrections

ecfr_list_corrections_by_title

ecfr_search_regulations

ecfr_get_search_count

ecfr_get_search_summary

ecfr_get_title_search_counts

ecfr_get_daily_search_counts

ecfr_get_hierarchy_search_counts

ecfr_get_search_suggestions

CourtListener MCP Server

When to use this vs. the official server

Use the hosted endpoint (no install)

Claude Desktop / Claude Code

Cursor

VS Code (GitHub Copilot Chat)

Claude Web (custom connector)

Windsurf, Continue, etc.

Tools

Authentication

Self-host

Docker

Python (uv)

Stdio (local CLI integration)

Configuration

Health check

Development

Changelog

0.2.0

Credits & License

Community

Install

Remote endpoint

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