lexifina/global-law：用Git版本控制全球法律文本及MCP工具

Git for Global Law: the law of every country as one git history, each country's record a submodule, every commit one law taking effect

GitHub repository created 2026-10-28 · 1001 stars in 2.5 days (about 398 a day) · HTML

Git for Global Law

The world's law in one git history. Every word traced to the law that wrote it for any country and any date.

An expansion of the same for the US Code, #1 on Hacker News (28/10/26). Semantic, searchable law on a global scale.

Free to use: CC0. Fork it, build on it, ship it in a product: no permission or credit needed. The law text sits in each country's repository, under that repository's own terms.

The law of many jurisdictions as one git history. Each jurisdiction's law is its own repository, where every commit is one law taking effect, written by that law. This repository arranges those repositories by jurisdiction and interleaves their histories in the order the changes took force, so a single commit here is the state of all of them on one day.

Each country's law lives in its own repository, `lexifina/-law`, which says where it belongs here in a `corpus.json` at its root. A country whose repository still holds only its sources (no law yet) has a folder with its `jurisdiction.json` and `SOURCES.md`, and no submodule: only real law is pinned. Laws adopted but not yet in force stay on each corpus's future branch; `main` here holds only what is in force by the build date.

Corpora differ widely in reach. Some hold a country's whole statute book (Czechia, Spain, Switzerland, Georgia, Malta); others hold a few acts, or a sample: the US corpus is nine titles of the United States Code, and the UK corpus is the special educational needs law. `manifest.json` gives each corpus's `coverage`, and `history` says how its past is known: `in-force` (dated official versions), `replayed` (rebuilt by applying each amending act; its `verification` says which dates were checked) or `current-only` (today's text only).

Using it from an AI model (MCP)

`tools/mcp_server.py` is a Model Context Protocol server for this tree. It lets Claude or any other MCP client ask the law what it said on a date, and every answer states where its record starts and ends. It uses only Python 3.10+ and git, runs on your machine over stdio, reads the repository and changes nothing. It makes no network calls.

For other clients (Claude Desktop, Cursor and the like), add this to their MCP settings:

Then ask in plain words, for example:

• "What did 11 U.S.C. §1182(1) say on 1 May 2022, and which law last changed it?" - "A case was commenced on 2022-05-01 under §1182. Which text applies, period by period?" - "Is the text of s. 42 Children and Families Act 2014 that the Court of Appeal applied in 2020 still in force?" - "Which provisions rely on 11 U.S.C. §1182, and which judgments does the record hold for it?" - "Check every citation in this brief against the law in force today."

It has 18 read-only tools, three prompts and a resource template. The tools cover finding a provision, reading it on a date, who wrote each word, comparing dates, a provision's history, the laws between two dates, searching the text and the change notes, when words entered or left the law, what else a change affects, checking precedent, resolving the citations in a brief, and which text applies to a case. Old paths with ISO country codes (`us/federal/usc/...`, `de`) are still read. MCP.md has the full tool list, the protocol versions, the security measures and how it compares with other law MCP servers. The tests are `python -m unittest tests.test_mcp`.

How it is built

• The first commit, dated 1 January 1970, holds the jurisdiction tree and the list of corpora, and no law. - Every later commit moves exactly one corpus to its next commit. Its author is the law, as in the corpus, and its trailers name the corpus, the corpus commit, the law and the in-force date. - The order is the in-force date, keeping each corpus's own order. - The last commit adds this README, the tools and the tests. - The build is deterministic. When a corpus is rebuilt, for example after a correction, this repository is rebuilt from scratch and force-pushed.

Dates

Git cannot store dates before 1970, so changes to the Grundgesetz that took effect earlier carry 1970 commit dates, one second apart, in the right order. The `In-force` trailer is authoritative and the tools use it, so `law.py show 1956-03-19 …` works.

What it does not show

• Each corpus covers only what its README says. A file missing on a date can mean the provision was not yet in force or that the corpus does not reach that far back. - A later law that reaches back to earlier dates (retroactive application) is recorded in the corpus's commit messages but does not change the text shown on those earlier dates. - `git blame` works by line, so a line changed in part is credited to the last law that touched it. `law.py words` credits each word instead, by comparing each version with the one before; text rewritten in place is credited to the law that rewrote it, even where a few of its words are the same as before.

Visualisation suite

See all global law cohort visualisations and bridges here

Reading it

Dates must be written YYYY-MM-DD. When a date falls before a record starts or after it ends, the tools say so on stderr, because each country's record covers a different period (see `record_to` in `manifest.json`).

Plain git works too, with care: