get_legislation_regulation_metadata

Instructions

Implementation Reference

• src/index.ts:475-510 (handler)

  The handler/registration for the get_legislation_regulation_metadata tool. Fetches legislation metadata from the CanLII API (legislationBrowse endpoint) and returns the parsed response.

  // TOOL: get_legislation_regulation_metadata
  // ============================================================
  server.tool(
  	"get_legislation_regulation_metadata",
  	"Get metadata for a specific statute or regulation including its CanLII URL, citation, and table of contents. " +
  	"The URL links directly to the full legislation text on canlii.org — always provide this to the user.",
  	{
  		language: z.enum(["en", "fr"]).default("en")
  			.describe("Language: 'en' for English (default), 'fr' for French"),
  		databaseId: pathSegmentSchema
  			.describe("Legislation database ID (e.g., 'ons' for Ontario Statutes)"),
  		legislationId: pathSegmentSchema
  			.describe("Specific legislation ID from browse results"),
  	},
  	async ({ language, databaseId, legislationId }) => {
  		try {
  			const params = new URLSearchParams({ api_key: apiKey });
  
  			const response = await apiFetch(
  				`https://api.canlii.org/v1/legislationBrowse/${language}/${encodeURIComponent(databaseId)}/${encodeURIComponent(legislationId)}/?${params.toString()}`
  			);
  
  			if (!response.ok) {
  				return errorResponse(`Error: Failed to fetch legislation metadata (${response.status})`);
  			}
  
  			const data = await response.json();
  			const parsed = LegislationMetadataSchema.parse(data);
  			return jsonResponse(parsed);
  		} catch (error) {
  			return errorResponse(
  				`Error: ${error instanceof Error ? error.message : "Unknown error"}`
  			);
  		}
  	}
  );

• src/schema.ts:56-67 (schema)

  Zod validation schema for the legislation metadata response, defining the shape of data returned by the tool.

  export const LegislationMetadataSchema = z.object({
      legislationId: z.string(),
      url: z.string(),
      title: z.string(),
      citation: z.string(),
      language: z.string().optional(),
      dateScheme: z.string().optional(),
      startDate: z.string().optional(),
      endDate: z.string().optional(),
      repealed: z.string().optional(),
      content: z.array(LegislationMetadataContentSchema).optional(),
  }).passthrough();

• src/schema.ts:51-54 (schema)

  Sub-schema for the table of contents (content array) items within the legislation metadata.

  export const LegislationMetadataContentSchema = z.object({
      partId: z.string(),
      partName: z.string(),
  }).passthrough();

• src/index.ts:32-53 (helper)

  Helper rate-limited API fetch function used by the tool to call the CanLII API.

  async function apiFetch(url: string): Promise<Response> {
  	return new Promise((resolve, reject) => {
  		requestQueue = requestQueue.then(async () => {
  			const today = new Date().toDateString();
  			if (today !== dailyResetDate) {
  				dailyCount = 0;
  				dailyResetDate = today;
  			}
  			if (dailyCount >= 5000) {
  				throw new Error("Daily API limit reached (5,000 queries). Try again tomorrow.");
  			}
  			const now = Date.now();
  			const elapsed = now - lastRequestTime;
  			if (elapsed < MIN_INTERVAL_MS) {
  				await new Promise(r => setTimeout(r, MIN_INTERVAL_MS - elapsed));
  			}
  			lastRequestTime = Date.now();
  			dailyCount++;
  			return fetch(url);
  		}).then(resolve, reject);
  	});
  }

• src/index.ts:93-103 (helper)

  Helper response formatters: jsonResponse serializes data to JSON, errorResponse formats error messages (with API key redaction).

  function jsonResponse(data: unknown) {
  	return textResponse(JSON.stringify(data, null, 2));
  }
  
  function sanitizeError(message: string): string {
  	return message.replace(/api_key=[^&\s]*/gi, "api_key=REDACTED");
  }
  
  function errorResponse(message: string) {
  	return textResponse(sanitizeError(message));
  }