Building Your Own AI Agent on the Europaius Legal Corpus

For interactive use, standard OAuth sign-in takes place in the browser; the MCP SDK for both Python and TypeScript can handle it. For server-side agents and automations, use the API key from the Europaius pricing page: enter it at login instead of an email address, or have your own OAuth client complete authorisation once and store the refresh token. The key starts with the prefix eur_ and is tied to the account and its limits.

• search(query, states): returns JSON {"results":[{id,title,url,snippet}]} across legislation and case law.
• fetch(id): full text of a document by identifier, including metadata (court, date, ECLI, country).
• search_law, find_caselaw, find_caselaw_cz: targeted search within legislation or case law with parameters.
• get_paragraf(state, law, paragraf): exact wording of a section by statute number.
• souvislosti(para_id): verified citation links for a section.
• compare_norm(query, states): the most relevant provisions from each country.
• vyklad, list_states: interpretation of a Czech section, overview of coverage.

Identifiers returned by the search tool are stable and can be stored. Decisions of Czech courts: case:<court>:<slug>, where the court is ns, nss, us or justice — all Czech sources. Section: para:CZ:89/2012:§2991. Document from another jurisdiction: eu:DE:<id>. For decisions, the fetch tool returns the legal proposition, operative part and reasoning as a single text, up to 80,000 characters.

from mcp import ClientSession; from mcp.client.streamable_http import streamablehttp_client; async with streamablehttp_client("https://mcp.europaius.com/mcp", headers={"Authorization": "Bearer <token>"}) as (r, w, _): async with ClientSession(r, w) as s: await s.initialize(); res = await s.call_tool("search", {"query": "limitation of claims", "states": ["CZ"]}). The result is text containing JSON, which you parse as usual. You obtain the token either through the OAuth flow or from API key login.

• Give the agent a system instruction to call the tool for every legal claim and to include the URL from the result in its answer.
• Store document identifiers, not full texts; retrieve the full text only when actually needed.
• Expect the first query to a foreign jurisdiction to take longer; use a timeout of at least 120 seconds.
• Respect account limits; an agent running in a loop can burn through 100 queries quickly, so use a subscription for production.