Antu

Antu · Legal Diagrams

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Antu · Legal Diagrams turns case JSON into one offline HTML diagram—timelines, procedures, relationships, and court reasoning—for AI agents and legal professionals. The page is one file of about 2.3 MB that makes no network request and needs no server; it opens offline and can be archived, printed or sent as an attachment. An AI Agent can read the case materials and write the JSON; the engine then draws the diagram from it, and the same JSON gives the same diagram. Antu is at version 0.x, and the formats of the relationship and justification diagrams are still drafts.

Diagram Types

Four types of legal content, each drawn in several ways. A selector in the page switches between the ways; nothing in the JSON chooses one.

Relationship graph focus view relation matrix equity tree

authority chart related-party list relation path Fact timeline chronicle time scale Procedure flowchart route map Justification (experimental) reasoning tree

Relationship diagrams (seven ways of drawing the same JSON) show parties, roles and legal relationships; fact diagrams the time, the participants and how events went; procedure diagrams a procedural path and its branches; justification diagrams a conclusion drawn from norms and facts. The relationship and justification schemas are still drafts, and justification is currently experimental and on hold.

Four looks, called themes: document (black and white and square, for print and filing; the default), modern (rounded, pale), legal (navy) and dark (the modern look on a dark ground, for a dark host). The reader switches in the page, or a call fixes a page to one. Only the diagram is themed; dark also darkens the shell round it. See spec/theme.md.

Usage

npm install

npm run diagram -- examples/fact/neighbour-corridor-charging.en.json

The page is written beside the JSON file. The interface language of a page is set with ?lang=en or ?lang=zh; the case content is never translated.

Principle

Agent ──> key information ──> one JSON ──> engine ──> diagram

The engine does not write JSON, and the Agent does not draw. The model puts information into JSON; the engine draws. The JSON specification is a specification of its own, for four reasons:

1. General-purpose charting syntax is built on nodes, edges and state machines, and has no place for procedural standing or the source of a piece of evidence.
2. The diagram does not depend on which model extracted the information.
3. The same JSON gives the same diagram at any time and in any environment, so a diagram handed to a court or to the other side can be reproduced.
4. The source is recorded when the facts are extracted: each fact states the document, the page and the provision it rests on, and the diagram shows them. The materials themselves are neither bundled nor linked.

Agent Integration

The reference material for an Agent, for the fact diagram, is a field table of about 3.4k characters and a mechanism note of about 6.3k characters.

Skill

npx skills add zh-xx/Antu -g

The Skill is in skills/antu/; each release also carries it as antu-skill- .zip.

The command line asks the npm registry once a day whether a newer Antu is out (one GET request, nothing of any diagram) and, if so, ends its output with a notice. ANTU_NO_UPDATE_NOTIFIER=1 turns it off.

MCP

The MCP server is the npm package @zh-xx/antu, registered as io.github.zh-xx/antu in the MCP registry.

{

"mcpServers": { "antu": { "command": "npx", "args": ["-y", "-p", "@zh-xx/antu@latest", "antu-mcp"] } } }

Tools: antu_schema, antu_guide, antu_examples, antu_validate, antu_layout, antu_render, antu_preview, antu_versions.

DeepSeek Harness (DSH)

A native DSH plugin, @zh-xx/antu-dsh (Host tools + a chat card with a picker of the way of drawing), is on npm: dsh plugin --profile add @zh-xx/antu-dsh, then restart DSH. It needs DSH 0.2.0-rc.2 or newer. How it works and how it is tested: docs/dsh/dsh-plugin.md and tools/dsh/README.md. A profile that cannot use the plugin can still attach antu-mcp with a configuration-only bundle; the recipe and its limits are in tools/dsh/README.md.

In an Application

The same package has entries for an application's own code (spec/embed.md):

import { mount } from '@zh-xx/antu/embed'          // draw a diagram inside your page, in a shadow root

import { validate } from '@zh-xx/antu/validate' // check the JSON your model wrote; each error names its field import { renderHtml } from '@zh-xx/antu/html' // the self-contained page as a string (Node) import type { ProcedureSpec } from '@zh-xx/antu/types' // TypeScript shapes for each diagram JSON

const diagram = mount(element, spec, { lang: 'en', onEvent: (e) => console.log(e) })

Documentation

• Contracts under spec/ (what makes a JSON file or API call valid): versioning, themes, paper size, the MCP server, embedding, source types, and the diagram schemas (fact, procedure, relationship, justification). Agent mechanism notes: spec/agent/.
• Design and reference under docs/: architecture, layout engines, React Flow features, fact rendering, DSH plugin plan (install notes in tools/dsh/README.md).
• CHANGELOG.md. Known problems: GitHub issues. Working rules: CONTRIBUTING.md.

Security

• To report a vulnerability, use the private report described in SECURITY.md; please do not open a public issue for it.
• Every version of @zh-xx/antu and @zh-xx/antu-dsh on npm is published by GitHub Actions through npm's trusted publisher, with provenance: the page of the version on npm links back to the commit and the workflow run that made it. deps.dev shows the same record, with the known advisories (none at the time of writing) and the licence.
• A page made with Antu works offline and sends nothing anywhere; the command line asks once a day whether a newer version exists and sends nothing of a diagram (ANTU_NO_UPDATE_NOTIFIER=1 turns that off).

License

Copyright (C) 2026 Ji Cheng.

Antu is free software, licensed under the GNU Affero General Public License, version 3 or any later version (LICENSE, SPDX AGPL-3.0-or-later). In short: you may use, study, change and share it, including for commercial purposes. If you distribute a changed version, or let others use it over a network (for example as a hosted service), you must release your changes under the same licence, keep the copyright and licence notices, and make the source available. There is no warranty. This summary is not the licence; the licence text is.

• Additional permission (AGPL section 7). A page made with Antu contains Antu's code together with the diagram data you gave it. The diagram data, and the content of the diagram you drew from your material, are not part of Antu and are not covered by this licence: you may keep them private, publish them, or sell them on any terms you like. The licence covers Antu's code in the page, and the notices in the page must stay with it. The same text is in every page and at the top of the command line.
• If your company or an app store does not take AGPL software, or asks for an extra statement before it will l