Indigo Book MCP
Public repo: open-indiana-law/indigo-book.
Hosted unofficial MCP: indigo.openindianalaw.org (/mcp).
A local, read-only MCP of
The Indigo Book: A Manual of Legal Citation.
Full text of the CC0 second edition is searchable and retrievable by rule.
This is not The Bluebook and is not legal advice.
Source
Current edition in the store: Second Edition (2023 updates, 2nd printing),
HTML and PDF from indigobook.github.io.
The 2022 second edition and 2016 first edition are ingested as additional
editions. Public.Resource.Org dedicated the work to the public domain under
CC0 1.0.
Cite as: The Indigo Book: A Manual of Legal Citation (Christopher Sprigman &
Jennifer Romig et al. eds., Public.Resource.Org 2d ed. 2021).
Tools
indigo_search — full-text searchindigo_get_rule — one rule or table (R10.2, T3, A)indigo_get_text — rule plus nested subrules, or the whole bookindigo_browse — table of contents
Every response names the edition, CC0, and that this is not legal advice.
Setup
python3 -m pip install -e '.[dev]'
python3 -m indigo_book.ingest
INDIGO_BOOK_DB=data/store/indigo-book.db PYTHONPATH=src python3 -m indigo_book.mcp_server
python3 -m pytest
Default MCP transport is stdio. --http serves streamable HTTP on loopback
:8766 (landing /, terms /terms, MCP /mcp).
Hosted prototype
A hosted instance runs at https://indigo.openindianalaw.org (MCP endpoint
https://indigo.openindianalaw.org/mcp; landing at the root, terms at
/terms). Opening /mcp in a browser shows a JSON 406 error: that is the
machine protocol, not a broken site. Add it to Claude as a custom connector
with that URL, or to Claude Code with
claude mcp add --transport http indigo-book https://indigo.openindianalaw.org/mcp.
Usage counts (optional, off by default)
A host can count how often each tool is used. Set INDIGO_BOOK_USAGE_DB to a file path and the server records, per UTC
day and per tool or page, only the number of calls (or page opens) and errors. It never sees or stores IP addresses, queries, arguments, results
or session ids, so the totals cannot identify anyone, and a failure to write a count never breaks a tool. Read the totals
with python -m indigo_book.usage /path/to/usage.sqlite. The hosted prototype publishes this policy so users know what
is and is not measured.
Limits
No Bluebook text is included. No message to Public.Resource.Org. This copy
is unofficial and is not legal advice.
