What the door is

The MCP door is a thin server between your assistant and the LexAtlas API. It holds no data of its own: every call goes through your API key, with your rate limits and your jurisdiction scope, exactly as a direct API call would. A refusal stays a refusal — 403, 429, 404 and 503 reach the assistant with their code and our wording, so “not allowed” is never mistaken for “not found”.

Transport today is stdio: your MCP client starts the server on your host and talks to it locally; the server reaches the corpus through the same tunnel as the API (access model). Your key stays on your side.

A hosted endpoint that clients join by URL (Streamable HTTP) is in preparation. If your client can only connect by URL, say so in your request.

Tools

Two tools carry most of the work: one finds the provisions, the other reads them.

toollexatlas_search — find provisions by meaning

Hybrid search across the corpus: full-text and vector channels fused, across jurisdictions and languages. Use it when the assistant holds a question or a situation rather than a citation.

argument	type	meaning
`query`	string, required	the question or the wording, in any language the corpus holds
`jur`	string	jurisdictions, comma-separated: `ru`, `kz`, `by`, …
`k`	integer	how many rows to return; up to 20 on a pilot key

Each row carries the citation (cite), act code and title, act kind, status, language and which search channels matched. Pass the cite to lexatlas_get to read the article.

// arguments the assistant sends
{ "query": "penalty for late payment under a supply contract", "jur": "ru", "k": 5 }

toollexatlas_get — read the article

One article in full: the text, the act it belongs to, status (in force or repealed), how fresh our copy is, and provenance — the official source, its URL and the licence for reuse. With as_of it returns the text as it stood on that date, together with the amending law that set it (point-in-time; available for Russian codes).

argument	type	meaning
`cite`	string, required	`jurisdiction:act_code:article`, e.g. `ru:gk_rf_1:395`
`lang`	`ru` \| `en`	language of the trust envelope around the text
`as_of`	`YYYY-MM-DD`	the date to read the article on

// arguments the assistant sends
{ "cite": "ru:gk_rf_1:395", "as_of": "2024-01-01" }

Act codes are ours and have changed before. If you keep citations long-term, keep the act's requisites (date and number) next to them — requisites do not age.

All eleven tools

tool	what it answers
`lexatlas_verify`	Is the article real, in force or repealed, and how fresh is our copy.
`lexatlas_get`	Full text with the act, status and provenance — or as it stood on a chosen date.
`lexatlas_history`	When the article was changed and by which law, from the first version onwards.
`lexatlas_search`	Provisions across jurisdictions, found by wording or by the situation described.
`lexatlas_screen`	A name, alias or registered ID against official sanctions lists, quoted verbatim.
`lexatlas_changes`	Everything amended since a date you name — for monitoring, not re-reading.
`lexatlas_citecheck`	Every legal reference in a draft checked at once, so invented citations surface.
`lexatlas_pipeline`	Draft laws by stage — introduced, read, signed, published.
`lexatlas_coverage`	How complete a jurisdiction is, counted against the source's own register.
`lexatlas_calendar`	Provisions coming into force in the weeks ahead, with dates.
`lexatlas_related`	What an article relies on and what relies on it — with the meaning of each link.

Get a key

Write to us through the contact form: choose Legal-AI / data integration and add a line about what you are building. Keys are issued per client. Pilot key on request. Pricing on request.

With the key you receive the tunnel kit and the MCP server — one Python 3 file that uses only the standard library.

Configure your client

Claude Desktop, Cursor and most MCP clients read the same mcpServers block (Claude Desktop — claude_desktop_config.json; Cursor — .cursor/mcp.json):

{
  "mcpServers": {
    "lexatlas": {
      "command": "python3",
      "args": ["/path/to/lexatlas_mcp.py"],
      "env": {
        "LEXATLAS_API": "http://127.0.0.1:8788",
        "LEXATLAS_API_KEY": "lxa_…"
      }
    }
  }
}

Claude Code adds the same server with one command:

claude mcp add lexatlas \
  -e LEXATLAS_API=http://127.0.0.1:8788 \
  -e LEXATLAS_API_KEY=lxa_… \
  -- python3 /path/to/lexatlas_mcp.py

Other clients: any client that can launch a stdio MCP server — give it the same command and the same two environment variables. LEXATLAS_API is your end of the tunnel; LEXATLAS_API_KEY is the key we issue you.

Check the connection

From the host, without a key: curl -s http://127.0.0.1:8788/v1/health — the tunnel answers. Then ask the assistant to verify ru:gk_rf_1:196: it should call lexatlas_verify and report that the article exists and is in force. A wrong key comes back as a refusal with its code, not as an empty answer.

Limits

pilot key	ceiling
calls per minute	60
tool calls per day	1 000
rows per search	up to 20
rows returned per day	a daily ceiling, set per key

The exact ceilings, jurisdiction scope and expiry date of your key are served at /v1/limits. A call over a ceiling returns 429 with the reason. Load tests are agreed in advance: the rate window is shared by all your workers.

What to keep out of queries

Every call is recorded in our request log together with your key and the time — for quotas, abuse control and diagnosing your integration. Search and screening queries are stored as text, up to 300 characters.

Ask about the law, not about the person. “Liability of a guarantor under a loan” works better than a pasted client contract — and carries no one's data.
Keep personal data out: names of private individuals, passport and tax numbers, addresses, phone numbers, case facts, client documents.
Screening is the one tool that needs a name. Send only the name or registered ID being checked, with nothing around it.
Answers carry the text of the law. Content marked personal_data is served according to the entitlements on your key; handle it under your own data-protection rules.

What this is not

The tools answer specific questions — an article, a check, a list of changes. They are not a way to download the database: responses are bounded, and sequential enumeration of the corpus is watched. If you need the data itself rather than answers, tell us — that is a different conversation, and a fair one.

Request a key — pilot key on request, pricing on request.

Let your assistant look the law up itself