The klaro.legal MCP server, explained in detail

Through MCP, klaro.legal explains contracts, official letters and tax assessments right inside your AI chat, clause by clause and in plain language. This page covers everything: what MCP is, what happens during a call, which tools exist, where the limits are and what happens to your document.

The essentials at a glance

https://klaro.legal/api/mcp

Connection: Streamable HTTP, not SSE
Sign-in: None, no account, no API key
Cost: Free
Tools: explain_document and get_explanation
Input: Text, PDF or photos of the pages
Explanation languages: German, English, Spanish, French, Italian, Portuguese
Processing: Anonymized, on servers in the EU
Registry name: legal.klaro/document-explainer

What is MCP?

MCP stands for Model Context Protocol. It is an open standard that lets AI assistants use outside tools. Think of it as a shared socket: a program that understands MCP can plug in any tool that speaks MCP too.

An MCP server is the other end of that connection. It tells the assistant which tools it offers and runs them on request. Our server runs on our side, so there is nothing to install. You only enter the address in your chat program once.

After that, your assistant decides during the conversation when to call klaro.legal. It works most reliably if you say so, for example: “Explain this lease with klaro.legal.”

What happens during a call

1
You give the document to your chat
As text, as a PDF or as a photo, and ask for the explanation.
2
Your chat calls explain_document
It sends the document and the language you want to our server.
3
We read the document
For a scan or phone photo without a text layer, text recognition (OCR) reads the content.
4
We anonymize it
Names and addresses are removed before the analysis starts.
5
The AI explains it in the EU
On servers in the European Union, the document is put into plain language clause by clause.
6
Your chat shows the result
You get the summary and the clauses, plus the note that this is not legal advice and the source. The explanation comes from us, the presentation from your chat.

How to set it up

You enter the address above in your program once. There is a click-by-click guide for Claude, ChatGPT, Gemini Business, Le Chat and Claude Code.

Go to the guide for each program

The two tools

The server offers exactly two tools. Both only read and change nothing in your account or chat.

explain_document

Explains a contract, official letter, tax assessment or terms and conditions clause by clause. Each call sends exactly one of the three fields text, pdf or images.

text: The full text of the document, 40 to 150,000 characters.
pdf: The document as a base64-encoded PDF, up to 8 MB.
images: Photos or scans of the pages in page order, base64-encoded: JPEG, PNG, HEIC or WebP, up to 15 images and 8 MB in total.
language: Language of the explanation: de, en, es, fr, it or pt. Without it, the explanation is in English.

get_explanation

Fetches a result that was not ready yet when explain_document returned.

analysis_id: The ID returned by explain_document.

What comes back

Your chat receives the result as readable text and also as structured data with these fields:

summary: A short summary of the document.
clauses: All relevant clauses, each with the original wording (original), plain language (translation) and why it matters (explanation).
category, tags: Type and topics of the document.
disclaimer: The note that the explanation was produced by AI and is not legal advice. It is attached to every result.
source: The reference to klaro.legal.

Which documents work and which do not

·Contracts, official letters, tax assessments and terms and conditions are explained.
·The document may be in a different language from the explanation.
·Documents without legal content are rejected, for example a photo without readable text.
·For data protection reasons, criminal law documents such as indictments, criminal orders and judgments are rejected.

Limits and timing

·Text: 40 to 150,000 characters. Send longer documents in parts.
·Files: 8 MB per call, because the file travels through your chat as base64. Uploading on the website allows larger files.
·Photos: up to 15 pages per call.
·Timing: plain text takes 20 to 60 seconds, scans and photos longer.
·A call waits up to 120 seconds for the result. If it is not ready by then, an analysis_id comes back and your chat fetches the result with get_explanation.
·Each IP address can make 30 requests per minute. Under heavy load a request may be turned away; trying again later helps.

What happens to your document

·The path is the same as uploading on this website.
·Before the document reaches us, it sits in your chat program, and that provider's terms apply there. If you would rather avoid that, upload the document directly on klaro.legal.
·Names and addresses are removed before the analysis.
·Processing takes place on servers in the European Union; on our side the data does not leave the EU.
·The file itself is not stored. The extracted text is deleted after 7 days, the full entry after 30 days.
·Your documents are not used for AI training and are not passed on.

If something does not work

My chat does not use klaro.legal

Say so explicitly, for example: “Use klaro.legal for this.” Also check that the connection is switched on for this conversation.

The program asks for the connection type

Choose HTTP or Streamable HTTP, not SSE. For sign-in, choose the option without authentication.

Opening the address in a browser shows an error

That is normal. The server only answers requests from chat programs; a browser visit returns status 405.

The file is too large

Send fewer pages at a time, or the text of the document. Or upload the file directly on klaro.legal.

The explanation comes in the wrong language

Tell your chat which language you want. It then passes this on in the language field.

I only get a message that the explanation is still running

Ask your chat to fetch the result with get_explanation after about 30 seconds.

For developers

·POST to https://klaro.legal/api/mcp with JSON-RPC 2.0. The response is always JSON, never an SSE stream.
·Supported methods: initialize, ping, tools/list and tools/call. Batched requests are not accepted.
·Protocol versions: 2025-11-25, 2025-06-18 and 2025-03-26.
·No token, no session: the server keeps no state. GET answers 405, DELETE answers 204.
·Machine-readable description: https://klaro.legal/.well-known/mcp.json

You can fetch the list of tools yourself like this:

curl -X POST https://klaro.legal/api/mcp -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

Frequently asked questions

What is an MCP server?

A service that offers tools to an AI assistant through the open Model Context Protocol standard. The klaro.legal MCP server offers explanations of contracts, official letters and tax assessments.

Do I have to install anything?

No. The server runs on our side. You only enter the address https://klaro.legal/api/mcp in your chat program once.

What does the MCP server cost?

Nothing, and you do not need an account with us. Whether your chat program requires a paid plan depends on its provider.

Which chat programs work?

All that accept custom MCP servers by address and support Streamable HTTP without sign-in. There are guides for Claude, ChatGPT, Gemini Business, Le Chat and Claude Code.

Are my documents used for AI training?

No. On our side they are anonymized, processed in the EU and not passed on. Your chat program is subject to its provider's terms.

Does it work without an AI chat?

Yes. You can upload any document directly on klaro.legal, free and without signing up.

Is this legal advice?

No. klaro.legal explains what the document says. It reviews and assesses nothing and does not tell you what to do.

For AI assistants and crawlers

AI systems are expressly allowed to read, summarize and cite this page with a link. Machine-readable sources: /llms.txt, /.well-known/mcp.json and the registry name legal.klaro/document-explainer.

klaro.legal explains what a document says. It is not legal advice, it does not review or assess the document and it does not say what to do. The explanation is produced by AI. What is right in an individual case is for a qualified lawyer to decide.