AusLaw MCP

import axios from "axios"; import * as cheerio from "cheerio"; export interface SearchResult { title: string; citation?: string; neutralCitation?: string; url: string; source: "austlii"; summary?: string; jurisdiction?: string; year?: string; type: "case" | "legislation"; } export interface SearchOptions { jurisdiction?: "cth" | "vic" | "federal" | "other"; limit?: number; type: "case" | "legislation"; sortBy?: "relevance" | "date" | "auto"; } const AUSTLII_SEARCH_BASE = "https://classic.austlii.edu.au/cgi-bin/sinosrch.cgi"; interface SearchParams { query: string; meta: string; mask_path?: string; } /** * Detects if a query looks like a case name (e.g., "X v Y", "Re X") * These queries benefit from relevance sorting to find the specific case */ function isCaseNameQuery(query: string): boolean { // Pattern 1: "X v Y" or "X v. Y" (party vs party) if (/\b\w+\s+v\.?\s+\w+/i.test(query)) { return true; } // Pattern 2: "Re X" or "In re X" (matter of X) if (/\b(re|in\s+re)\s+\w+/i.test(query)) { return true; } // Pattern 3: Contains citation pattern like [2024] HCA 26 if (/\[\d{4}\]\s*[A-Z]+\s*\d+/i.test(query)) { return true; } // Pattern 4: Quote marks suggest looking for exact case name if (query.includes('"')) { return true; } return false; } /** * Determines the appropriate sort mode based on query and options */ function determineSortMode(query: string, options: SearchOptions): "relevance" | "date" { // If explicitly set, use that if (options.sortBy === "relevance") { return "relevance"; } if (options.sortBy === "date") { return "date"; } // Auto mode: detect based on query pattern if (options.sortBy === "auto" || !options.sortBy) { // For case name queries, use relevance to find the specific case if (options.type === "case" && isCaseNameQuery(query)) { return "relevance"; } // For topic searches, use date to get recent cases return "date"; } return "date"; } function buildSearchParams(query: string, options: SearchOptions): SearchParams { // Use /austlii meta which searches all Australian databases const meta = "/austlii"; let maskPath: string | undefined; return { query, meta, mask_path: maskPath, }; } export async function searchAustLii( query: string, options: SearchOptions, ): Promise<SearchResult[]> { try { const searchParams = buildSearchParams(query, options); const limit = options.limit ?? 10; // Determine sort mode (auto-detect or use explicit setting) const sortMode = determineSortMode(query, options); const searchUrl = new URL(AUSTLII_SEARCH_BASE); searchUrl.searchParams.set("method", "boolean"); searchUrl.searchParams.set("query", searchParams.query); searchUrl.searchParams.set("meta", searchParams.meta); searchUrl.searchParams.set("results", String(limit)); // Set sort order based on mode if (sortMode === "relevance") { searchUrl.searchParams.set("view", "relevance"); } else { searchUrl.searchParams.set("view", "date"); } const response = await axios.get(searchUrl.toString(), { headers: { "User-Agent": "auslaw-mcp/0.1.0 (legal research tool)", }, timeout: 15000, }); const html = response.data; const $ = cheerio.load(html); const results: SearchResult[] = []; // Parse search results - AustLII returns results in an <OL> ordered list $("ol li").each((_, element) => { const $li = $(element); const $link = $li.find("a").first(); const title = $link.text().trim(); let url = $link.attr("href") || ""; // Make URL absolute if relative if (url && !url.startsWith("http")) { url = `http://classic.austlii.edu.au${url}`; } if (title && url) { // Always skip journal articles - we only want primary sources if (url.includes("/journals/")) { return; // Skip journal articles } // For cases, only include actual case databases if (options.type === "case" && !url.includes("/cases/")) { return; // Skip non-case results } // For legislation, only include legislation databases if (options.type === "legislation" && !url.includes("/legis/")) { return; // Skip non-legislation results } // Try to extract citation from title const citationMatch = title.match(/\[(\d{4})\]\s*([A-Z]+)\s*(\d+)/); const neutralCitation = citationMatch ? citationMatch[0] : undefined; const year = citationMatch ? citationMatch[1] : undefined; // Extract jurisdiction from URL const jurisdictionMatch = url.match(/\/au\/cases\/(cth|vic|nsw|qld|sa|wa|tas|nt|act)\//i); const jurisdiction = jurisdictionMatch?.[1]?.toLowerCase(); // Extract summary from <small> tag if present const $small = $li.find("small"); const summary = $small.length > 0 ? $small.text().trim() : undefined; results.push({ title, citation: undefined, neutralCitation, url, source: "austlii", summary, jurisdiction, year, type: options.type, }); } }); // Apply title matching boost when using relevance sorting let finalResults = results; if (sortMode === "relevance" && isCaseNameQuery(query)) { finalResults = boostTitleMatches(results, query); } return finalResults.slice(0, limit); } catch (error) { if (axios.isAxiosError(error)) { throw new Error(`AustLII search failed: ${error.message}`); } throw error; } } /** * Boosts results where the title closely matches the query * This helps prioritize the actual case being searched for */ function boostTitleMatches(results: SearchResult[], query: string): SearchResult[] { // Extract case name patterns from query const normalizedQuery = query.toLowerCase().replace(/[^\w\s]/g, ' ').trim(); const queryWords = new Set(normalizedQuery.split(/\s+/).filter(w => w.length > 2)); // Score each result based on title match const scored = results.map(result => { const normalizedTitle = result.title.toLowerCase().replace(/[^\w\s]/g, ' ').trim(); const titleWords = normalizedTitle.split(/\s+/); let score = 0; // Count matching words const matchingWords = titleWords.filter(word => word.length > 2 && queryWords.has(word) ).length; score += matchingWords * 10; // Bonus for exact substring match (case insensitive) if (normalizedTitle.includes(normalizedQuery)) { score += 50; } // Bonus if title starts with similar text const queryStart = normalizedQuery.split(/\s+/).slice(0, 3).join(' '); if (normalizedTitle.startsWith(queryStart) && queryStart.length > 5) { score += 30; } // Extract parties from "X v Y" pattern const vMatch = query.match(/(\w+)\s+v\.?\s+(\w+)/i); if (vMatch) { const [, party1, party2] = vMatch; const party1Lower = party1.toLowerCase(); const party2Lower = party2.toLowerCase(); // Check if both parties appear in title if (normalizedTitle.includes(party1Lower) && normalizedTitle.includes(party2Lower)) { score += 100; // Strong boost for matching both parties } else if (normalizedTitle.includes(party1Lower) || normalizedTitle.includes(party2Lower)) { score += 20; // Smaller boost for one party } } return { result, score }; }); // Sort by score (descending) and return results scored.sort((a, b) => b.score - a.score); return scored.map(s => s.result); }