A2A server 4_APIs Manager Agent.js

const apiKey = "###"; // Please set your API key for using Gemini API.
const agentCardUrls = [];

/**
 * This is a sample agent card.
 * You can see the specification of the agent card at the following official site.
 * Ref: https://google.github.io/A2A/specification/
 * 
 * This agent card of "Currency Exchange Rates Tool" is from
 * https://google.github.io/A2A/specification/#56-sample-agent-card
 * https://github.com/google/A2A/blob/main/samples/python/agents/langgraph/__main__.py#L28
 */
const getAgentCard_ = _ => (
  {
    "name": "APIs Manager Agent",
    "description": [
      `Provide management for using various APIs.`,
      `- Run with exchange values between various currencies. For example, this answers "What is the exchange rate between USD and GBP?".`,
      `- Return the weather information by providing the location and the date, and the time.`,
    ].join("\n"),
    "provider": {
      "organization": "Tanaike",
      "url": "https://github.com/tanaikech"
    },
    "version": "1.0.0",
    "url": `${ScriptApp.getService().getUrl()}?accessKey=sample`,
    "defaultInputModes": ["text/plain"],
    "defaultOutputModes": ["text/plain"],
    "capabilities": {
      "streaming": false,
      "pushNotifications": false,
      "stateTransitionHistory": false,
    },
    "skills": [
      {
        "id": "get_exchange_rate",
        "name": "Currency Exchange Rates Tool",
        "description": "Helps with exchange values between various currencies",
        "tags": ['currency conversion', 'currency exchange'],
        "examples": ['What is exchange rate between USD and GBP?'],
        "inputModes": ["text/plain"],
        "outputModes": ["text/plain"]
      },
      {
        "id": "get_current_weather",
        "name": "Get current weather",
        "description": "This agent can return the weather information by providing the location and the date, and the time.",
        "tags": ["weather"],
        "examples": [
          "Return the weather in Tokyo for tomorrow's lunchtime.",
          "Return the weather in Tokyo for 9 AM on May 27, 2025.",
        ],
        "inputModes": ["text/plain"],
        "outputModes": ["text/plain"]
      }
    ]
  }
);

/**
 * This is an object including sample functions. These functions are used for creating the response data to the A2A client.
 * You can see the specification of this object as follows.
 * Ref: https://github.com/tanaikech/GeminiWithFiles?tab=readme-ov-file#use-function-calling
 * 
 * get_exchange_rate is from the Google's sample as follows.
 * Ref: https://github.com/google/A2A/blob/main/samples/python/agents/langgraph/agent.py#L19
 */
const getFunctionsA2A_ = _ => (
  {
    params_: {
      get_exchange_rate: {
        description: "Use this to get current exchange rate.",
        parameters: {
          type: "object",
          properties: {
            currency_from: {
              type: "string",
              description: "Source currency (major currency). Default is USD."
            },
            currency_to: {
              type: "string",
              description: "Destination currency (major currency). Default is EUR."
            },
            currency_date: {
              type: "string",
              description: "Date of the currency. Default is latest. It should be ISO format (YYYY-MM-DD)."
            }
          },
          required: ["currency_from", "currency_to", "currency_date"]
        }
      },

      get_current_weather: {
        description: [
          "Use this to get the weather using the latitude and the longitude.",
          "At that time, convert the location to the latitude and the longitude and provide them to the function.",
          `The date is required to be included. The date format is "yyyy-MM-dd HH:mm"`,
          `If you cannot know the location, decide the location using the timezone.`,
        ].join("\n"),
        parameters: {
          type: "object",
          properties: {
            latitude: {
              type: "number",
              description: "The latitude of the inputed location."
            },
            longitude: {
              type: "number",
              description: "The longitude of the inputed location."
            },
            date: {
              type: "string",
              description: `Date for searching the weather. The date format is "yyyy-MM-dd HH:mm"`
            },
            timezone: {
              type: "string",
              description: `The timezone. In the case of Japan, "Asia/Tokyo" is used.`
            },
          },
          required: ["latitude", "longitude", "date", "timezone"]
        }
      }

    },

    /**
     * Ref: https://github.com/google/A2A/blob/main/samples/python/agents/langgraph/agent.py#L19
     */
    get_exchange_rate: (object) => {
      console.log("Run the function get_exchange_rate.");
      console.log(object); // Check arguments.
      const { currency_from = "USD", currency_to = "EUR", currency_date = "latest" } = object;
      let res;
      try {
        const resStr = UrlFetchApp.fetch(`https://api.frankfurter.app/${currency_date}?from=${currency_from}&to=${currency_to}`).getContentText();
        const obj = JSON.parse(resStr);
        res = [
          `The raw data from the API is ${resStr}. The detailed result is as follows.`,
          `The currency rate at ${currency_date} from "${currency_from}" to "${currency_to}" is ${obj.rates[currency_to]}.`,
        ].join("\n");
      } catch ({ stack }) {
        res = stack;
      }
      console.log(res); // Check response.
      return { result: res };
      // return { result: { type: "text", text: res, metadata: null } };
    },

    /**
     * This function returns the current weather.
     * The API is from https://open-meteo.com/
     *
     * { latitude = "35.681236", longitude = "139.767125", date = "2025-05-27 12:00", timezone = "Asia/Tokyo" } is Tokyo station.
     */
    get_current_weather: (object) => {
      console.log("Run the function get_current_weather.");
      console.log(object); // Check arguments.
      const { latitude = "35.681236", longitude = "139.767125", date = "2025-05-27 12:00", timezone = "Asia/Tokyo" } = object;
      let res;
      try {

        // Ref: https://open-meteo.com/en/docs?hourly=weather_code&current=weather_code#weather_variable_documentation
        const code = {
          "0": "Clear sky",
          "1": "Mainly clear, partly cloudy, and overcast",
          "2": "Mainly clear, partly cloudy, and overcast",
          "3": "Mainly clear, partly cloudy, and overcast",
          "45": "Fog and depositing rime fog",
          "48": "Fog and depositing rime fog",
          "51": "Drizzle: Light, moderate, and dense intensity",
          "53": "Drizzle: Light, moderate, and dense intensity",
          "55": "Drizzle: Light, moderate, and dense intensity",
          "56": "Freezing Drizzle: Light and dense intensity",
          "57": "Freezing Drizzle: Light and dense intensity",
          "61": "Rain: Slight, moderate and heavy intensity",
          "63": "Rain: Slight, moderate and heavy intensity",
          "65": "Rain: Slight, moderate and heavy intensity",
          "66": "Freezing Rain: Light and heavy intensity",
          "67": "Freezing Rain: Light and heavy intensity",
          "71": "Snow fall: Slight, moderate, and heavy intensity",
          "73": "Snow fall: Slight, moderate, and heavy intensity",
          "75": "Snow fall: Slight, moderate, and heavy intensity",
          "77": "Snow grains",
          "80": "Rain showers: Slight, moderate, and violent",
          "81": "Rain showers: Slight, moderate, and violent",
          "82": "Rain showers: Slight, moderate, and violent",
          "85": "Snow showers slight and heavy",
          "86": "Snow showers slight and heavy",
          "95": "Thunderstorm: Slight or moderate",
          "96": "Thunderstorm with slight and heavy hail",
          "99": "Thunderstorm with slight and heavy hail"
        };
        const endpoint = `https://api.open-meteo.com/v1/forecast?latitude=${latitude}&longitude=${longitude}&hourly=weather_code&timezone=${encodeURIComponent(timezone)}`;
        const resObj = UrlFetchApp.fetch(endpoint, { muteHttpExceptions: true });
        if (resObj.getResponseCode() == 200) {
          const obj = JSON.parse(resObj.getContentText())
          const { hourly: { time, weather_code } } = obj;
          const widx = time.indexOf(date.replace(" ", "T").trim());
          if (widx != -1) {
            res = code[weather_code[widx]];
          } else {
            res = "No value was returned. Please try again.";
          }
        } else {
          res = "No value was returned. Please try again.";
        }
      } catch ({ stack }) {
        res = stack;
      }
      console.log(res); // Check response.
      return { result: res };
      // return { result: { type: "text", text: res, metadata: null } };
    }

  }
);


// doGet and doPost are used for connecting between the A2A server and the A2A client with the HTTP request.
const doGet = (e) => main(e);
const doPost = (e) => main(e);

function main(eventObject) {
  try {
    const object = {
      eventObject,
      agentCard: getAgentCard_,
      functions: getFunctionsA2A_,
      apiKey,
      agentCardUrls,
    };
    const res = new A2AApp({ accessKey: "sample" }).server(object);
    console.log(res.getContent()); // Check response.
    return res;
  } catch ({ stack }) {
    console.log(stack);
    return ContentService.createTextOutput(stack);
  }
}

/**
 * This function is used for retrieving the URL of the Web Apps.
 * Please directly run this function and copy the URL from the log.
 */
function getServerURL() {
  const serverURL = `${ScriptApp.getService().getUrl()}?accessKey=sample`;
  console.log(serverURL);


  // The following comment line is used for automatically detecting the scope of "https://www.googleapis.com/auth/drive.readonly". This scope is used for accessing Web Apps. So, please don't remove the comment.
  // DriveApp.getFiles();
}

/**
 * This function is used for retrieving the URL for registering the AgentCard to Python demo script.
 * Please directly run this function and copy the URL from the log.
 */
function getRegisteringAgentCardURL() {
  const registeringAgentCardURL = `${ScriptApp.getService().getUrl()}?access_token=${ScriptApp.getOAuthToken()}&accessKey=sample`;
  console.log(registeringAgentCardURL);
}