check-session

Instructions

Implementation Reference

• src/tools.ts:106-131 (handler)

  The handler function for the 'check-session' tool. It checks if a saved Garmin Connect session exists, and if so, tests it by calling the userprofile API. On success returns {status:'ok', profile}. On failure resets the shared client and returns an error.

  server.tool(
    "check-session",
    "Check if the saved Garmin Connect session is still valid. MUST be called after garmin-login to verify authentication worked.",
    {},
    async () => {
      if (!sessionExists()) {
        return errorResult(
          "No session file found. Call the garmin-login tool for instructions."
        );
      }
      try {
        const client = getClient();
        const profile = await client.get(
          "userprofile-service/userprofile/user-settings/"
        );
        return jsonResult({ status: "ok", profile });
      } catch (e) {
        const msg = e instanceof Error ? e.message : String(e);
        // Reset the singleton so the next attempt re-reads the session file
        await resetSharedClient();
        return errorResult(
          `Session invalid or expired: ${msg}\nCall the garmin-login tool to re-authenticate.`
        );
      }
    }
  );

• src/index.ts:7-41 (registration)

  Registration via registerTools(server) which calls the registration function in tools.ts that registers all tools including 'check-session' via server.tool().

  async function startMcpServer(): Promise<void> {
    const server = new McpServer({
      name: "garmin-connect-mcp",
      version: "0.1.0",
    });
  
    registerTools(server);
    registerResources(server);
  
    const transport = new StdioServerTransport();
    await server.connect(transport);
    console.error("garmin-connect-mcp server running on stdio");
  }
  
  async function main(): Promise<void> {
    const command = process.argv[2];
  
    if (command === "login") {
      const { runLogin } = await import("./auth.js");
      await runLogin();
    } else {
      await startMcpServer();
    }
  }
  
  main().catch((err) => {
    console.error("Fatal error:", err);
    process.exit(1);
  });

• src/tools.ts:32-39 (helper)

  getClient() helper called inside check-session handler; uses sessionExists() to check for session file and returns the shared client via getSharedClient().

  function getClient() {
    if (!sessionExists()) {
      throw new Error(
        "No Garmin session found. The user needs to run: npx garmin-connect-mcp login"
      );
    }
    return getSharedClient();
  }

• src/garmin-client.ts:27-29 (helper)

  sessionExists() helper that checks if the session.json file exists on disk. Used by the check-session handler to determine if there is a saved session.

  export function sessionExists(): boolean {
    return existsSync(SESSION_FILE);
  }