GA4 MCP Server

Instructions

Implementation Reference

• src/tools/analytics/getExitPages.ts:13-63 (handler)

  The core handler function that executes the get_exit_pages tool logic. It queries GA4 for pagePath dimensions with screenPageViews and sessions metrics, approximates exit rates, and returns a list of exit pages.

  export async function getExitPages(
    input: GetExitPagesInput
  ): Promise<GetExitPagesOutput> {
    const propertyId = getPropertyId(input.propertyId);
    const property = formatPropertyPath(propertyId);
    const dateRange = periodToDateRange(input.period);
    const limit = input.limit || 10;
  
    // GA4では直接exitPageディメンションがないため、
    // pagePath と screenPageViews を使って近似する
    const response = await executeReport({
      property,
      dateRanges: [dateRange],
      dimensions: [{ name: "pagePath" }],
      metrics: [{ name: "screenPageViews" }, { name: "sessions" }],
      orderBys: [{ metric: { metricName: "screenPageViews" }, desc: true }],
      limit,
    });
  
    // 合計セッション数を取得
    const totalSessions =
      response.totals?.[0]?.metricValues?.[1]?.value
        ? parseFloat(response.totals[0].metricValues[1].value)
        : 0;
  
    const exitPages: ExitPage[] = [];
  
    for (const row of response.rows || []) {
      const dimensionValues = row.dimensionValues || [];
      const metricValues = row.metricValues || [];
  
      const pageViews = metricValues[0]?.value
        ? Math.round(parseFloat(metricValues[0].value))
        : 0;
  
      const sessions = metricValues[1]?.value
        ? Math.round(parseFloat(metricValues[1].value))
        : 0;
  
      // 離脱数をセッション数で近似（実際の離脱数とは異なる可能性あり）
      const exits = sessions;
  
      exitPages.push({
        pagePath: dimensionValues[0]?.value || "",
        exits,
        exitRate: calculatePercentage(exits, totalSessions),
      });
    }
  
    return { exitPages };
  }

• src/types.ts:271-285 (schema)

  TypeScript interfaces defining the input schema (GetExitPagesInput), data structure (ExitPage), and output schema (GetExitPagesOutput) for the get_exit_pages tool.

  // get_exit_pages
  export interface GetExitPagesInput extends PropertyId {
    period: ShortPeriod;
    limit?: number;
  }
  
  export interface ExitPage {
    pagePath: string;
    exits: number;
    exitRate: string;
  }
  
  export interface GetExitPagesOutput {
    exitPages: ExitPage[];
  }

• src/server.ts:378-397 (registration)

  Registers the get_exit_pages tool in the MCP server's tools list, defining its name, description, and input schema.

  {
    name: "get_exit_pages",
    description: "離脱ページ（ユーザーが最後に見たページ）の分析結果を取得します。",
    inputSchema: {
      type: "object" as const,
      properties: {
        propertyId: { type: "string", description: "GA4プロパティID" },
        period: {
          type: "string",
          enum: ["7days", "28days", "30days"],
          description: "集計期間",
        },
        limit: {
          type: "number",
          description: "取得件数（デフォルト: 10）",
        },
      },
      required: ["period"],
    },
  },

• src/server.ts:695-700 (registration)

  In the tool dispatch switch statement, handles calls to get_exit_pages by invoking the getExitPages handler with parsed arguments.

  case "get_exit_pages":
    return await getExitPages({
      propertyId: args.propertyId as string | undefined,
      period: args.period as "7days" | "28days" | "30days",
      limit: args.limit as number | undefined,
    });