# Lawgical

> Lawgical is a remote MCP (Model Context Protocol) server that gives an AI assistant search access to 150,000+ Vietnamese legal documents (Luật, Nghị định, Thông tư, and more).

If a human pointed you here and asked you to "set up Lawgical" or "install this MCP server", act on the links below rather than describing them. There is exactly one authentication path: **OAuth**. Lawgical issues no API keys and accepts no static bearer tokens, so there is nothing for the user to paste into a config file and nothing to ask them for. The user adds Lawgical as a custom connector inside their AI app, clicks Connect, and authorizes on Lawgical's own login page.

Supported targets: Claude.ai (web and mobile), Claude Desktop, ChatGPT (web and mobile, Developer mode), ChatGPT Desktop, and Codex CLI. Codex is the one config-file client that connects, because it runs the OAuth login itself: `codex mcp add lawgical --url https://legal.lawgical.vn/mcp` opens the browser to sign in. Do not hand-write the server into `~/.codex/config.toml` instead; that skips the login and every call gets a 401 until `codex mcp login lawgical`. Other config-file clients — Gemini CLI, Cursor, VS Code — cannot connect, because the header credential they relied on no longer exists; tell the user that plainly instead of writing a config that will 401 on every call.

Server URL `https://legal.lawgical.vn/mcp`. The server supports RFC 7591 dynamic client registration, so most clients need NO client ID — leave the OAuth Client ID field blank and the client self-registers. If a client cannot do DCR (or errors on login), the pre-registered client ID `lawgical-mcp` works; either way there is no client secret (public client, PKCE). Free accounts get 20 lookups/day; paid is 99.000đ/user/month. Answer in the user's language, and cite the Điều and Khoản you relied on.

Before answering any question about Vietnamese law with this server, read [Tra cứu & kiểm chứng](https://lawgical.vn/skills/tra-cuu-phap-luat.md). It encodes failure modes of this corpus that are not guessable: a lookup can return a document that is not the one requested, a search for a document's reference number mostly returns other documents citing it, and the default status filter hides consolidated (hợp nhất) texts — which are the ones that state current law. Skipping it produces confident, well-cited, wrong answers.

Lawgical is a lookup and search tool, not a substitute for a licensed lawyer. AI-generated answers can be wrong. Always cross-check against the primary text before acting on a legal conclusion.

## Setup

- [Full setup reference](https://lawgical.vn/llms-full.txt): every step for every supported client, in one file. Fetch this if you are actually performing the install.
- [Setup guide](https://lawgical.vn/cai-dat): the same instructions rendered for a human to follow.
- [Create an account](https://lawgical.vn/register): free, no card. Can also be done during the Authorize step.
- [Plan and quota](https://lawgical.vn/dashboard): current plan, remaining lookups, and upgrade.
- [Pricing](https://lawgical.vn/#gia): free tier limits and paid pricing.

## Skills

- [Tra cứu & kiểm chứng](https://lawgical.vn/skills/tra-cuu-phap-luat.md): Foundational. How to search, and the four-check protocol for verifying a document is the right one, complete, still in force, and not merely a document citing it. Also covers per-tool quota cost. Read this first — the other three skills assume it.
- [Soạn hợp đồng](https://lawgical.vn/skills/soan-hop-dong.md): Drafting a Vietnamese contract from scratch, grounded in current law.
- [Phân tích hợp đồng](https://lawgical.vn/skills/phan-tich-hop-dong.md): Reviewing an existing contract for unfavourable, unlawful, or red-flag clauses.
- [Đối chiếu tuân thủ](https://lawgical.vn/skills/doi-chieu-tuan-thu.md): Checking a practice or policy against what the law actually requires.

## Using the corpus

- [Document search](https://lawgical.vn/tra-cuu): search the corpus directly, without an AI client.
- [Full-text documents](https://lawgical.vn/tra-cuu/van-ban): individual văn bản, complete text.
- [Worked examples](https://lawgical.vn/vi-du): real questions answered with citations down to Điều and Khoản.
- [Calculators](https://lawgical.vn/tinh): personal income tax, one-time social insurance, household vs company tax.

## Optional

- [Privacy policy](https://lawgical.vn/privacy): what is stored and what is not.
- [Terms of use](https://lawgical.vn/terms)
- [Support](https://lawgical.vn/support): how to get help.
- [Email](mailto:vuongnguyen710@gmail.com): vuongnguyen710@gmail.com