---
title: "Configure functions directory"
url: https://docs.catalyst.zoho.com/en/tutorials/leadmanager/nodejs/configure-functions-directory/
description: "Build a Lead Manager application that connects to your Zoho CRM account using Catalyst connector, and enables you to view, create, update, or delete leads from the Leads module directly"
last_updated: 2026-08-17T12:16:04Z
service: All Services
type: tutorial
related_links:
  - name: "Advanced I/O Functions"
    url: /en/serverless/help/functions/advanced-io/
  - name: "Functions Directory Structure"
    url: /en/cli/v1/project-directory-structure/functions-directory
---

# Configure the Functions Directory

We will now begin coding the Lead Manager application by configuring the Advanced I/O function.

The functions directory [](https://docs.catalyst.zoho.com/en/cli/v1/project-directory-structure/functions-directory) `functions/crm\_crud` contains:

* The `index.js` main function file
* The `catalyst-config.json` configuration file
* Node modules
* `[package.json](https://docs.npmjs.com/files/package.json)` and `[package-lock.json](https://docs.npmjs.com/configuring-npm/package-lock-json.html)` dependency files

You will be adding code in `index.js`.

You can use any IDE to configure the function.

> **Note:** Please go through the code in this section to make sure you fully understand it. We will discuss the function and client code, after you configure the client.

### Install Express and Node Fetch Frameworks for Node.js

The Node.js function requires three frameworks to be installed. You must install the [express](https://expressjs.com/), [node-fetch](https://www.npmjs.com/package/node-fetch), and [axios](https://www.npmjs.com/package/axios) dependencies to import those packages in your code.

#### `express`

To install `Express.js`, navigate to the Node function's directory (`functions/crm\_crud`) in your terminal and execute the following command:

```sh
 npm install express --save
```

This will install the Express module and save the dependencies.

![catalyst_leadmanager_install_express](https://catalyst-docs-development.zohostratus.in/images/tutorials/leadmanager/catalyst_leadmanager_install_express.webp) 

#### `node-fetch`

To install `node-fetch`, execute the following command from the Node function's directory navigate to the Node function's directory (`functions/crm\_crud`):

```sh
 npm install node-fetch
```

This will install the module.

![catalyst_leadmanager_install_node_fetch](https://catalyst-docs-development.zohostratus.in/images/tutorials/leadmanager/catalyst_leadmanager_install_node_fetch.webp)

#### `axios`

To install `axios`, execute the following command from the Node function's directory navigate to the Node function's directory (`functions/crm\_crud`):

```sh
 npm install axios
```

This will install the module.

![catalyst_leadmanager_install_axios](https://catalyst-docs-development.zohostratus.in/images/tutorials/leadmanager/catalyst_leadmanager_install_axios.webp) 

This information will also be updated in the [package.json](https://docs.npmjs.com/files/package.json) file.

```json
{
	"name": "crm_crud",
	"version": "1.0.0",
	"main": "index.js",
	"author": "amelia.burrows@zylker.com",
	"dependencies": {
		"axios": "^0.27.2",
		"express": "^4.18.1",
		"node-fetch": "^3.2.6",
		"zcatalyst-sdk-node": "latest"
	}
}
```

You can now add the code in the function file.

Copy the code below and paste it in `index.js` located in `functions/crm\_crud` directory and save the file.

**index.js**

```javascript
"use strict";
const express = require("express");
const http = require("https");
const app = express();
app.use(express.json());
const catalyst = require("zcatalyst-sdk-node");
const HOST = "www.zohoapis.com";
const AUTH_HOST = "https://accounts.zoho.com/oauth/v2/token";
const PORT = 443;
const axios = require("axios");
const CLIENTID = '{{YOUR_CLIENT_ID}}'; //Add your client ID
const CLIENT_SECRET = '{{YOUR_CLIENT_SECRET}}'; //Add your client secret
app.get("/generateToken", async (req, res) => {
  try {
    const catalystApp = catalyst.initialize(req);
    const code = req.query.code;
    let userManagement = catalystApp.userManagement();
    let userDetails = await userManagement.getCurrentUser();
	const domain = `${process.env.X_ZOHO_CATALYST_IS_LOCAL === 'true' ? "http" : "https"}://${process.env.X_ZOHO_CATALYST_IS_LOCAL === 'true' ? req.headers.host : req.headers.host.split(':')[0]}`
    const refresh_token = await getRefreshToken(code, res, domain);
    const userId = userDetails.user_id;
    const catalystTable = catalystApp.datastore().table("Token");
    await catalystTable.insertRow({
      refresh_token,
      userId,
    });
    res.status(200).redirect(`${domain}/app/index.html`);
  } catch (err) {
    console.log(err);
    res
      .status(500)
      .send({
        message: "Internal Server Error. Please try again after sometime.",
        error: err,
      });
  }
});
app.get("/getUserDetails", async (req, res) => {
  try {
    const catalystApp = catalyst.initialize(req);
    const userDetails = await getUserDetails(catalystApp);
    if (userDetails.length !== 0) {
      res.status(200).send({ userId: userDetails[0].Token.userId });
    } else {
      res.status(200).send({ userId: null });
    }
  } catch (err) {
    console.log(err);
    res
      .status(500)
      .send({
        message:
          "Internal Server Error in Getting User Details. Please try again after sometime.",
        error: err,
      });
  }
});
app.get("/crmData", async (req, res) => {
  try {
    console.log();
    const catalystApp = catalyst.initialize(req);
    const userDetails = await getUserDetails(catalystApp);
    const accessToken = await getAccessToken(catalystApp, userDetails);
    const options = {
      hostname: HOST,
      port: PORT,
      method: "GET",
      path: `/crm/v2/Leads`,
      headers: {
        Authorization: `Zoho-oauthtoken ${accessToken}`,
      },
    };
    var data = "";
    const request = http.request(options, function (response) {
      response.on("data", function (chunk) {
        data += chunk;
      });
      response.on("end", function () {
        console.log(response.statusCode);
        res.setHeader("content-type", "application/json");
        res.status(200).send(data);
      });
    });
    request.end();
  } catch (err) {
    console.log(err);
    res
      .status(500)
      .send({
        message: "Internal Server Error. Please try again after sometime.",
      });
  }
});
app.get("/crmData/:id", async (req, res) => {
  try {
    const catalystApp = catalyst.initialize(req);
    const userDetails = await getUserDetails(catalystApp);
    const accessToken = await getAccessToken(catalystApp, userDetails);
    const options = {
      hostname: HOST,
      port: PORT,
      method: "GET",
      path: `/crm/v2/Leads/${req.params.id}`,
      headers: {
        Authorization: `Zoho-oauthtoken ${accessToken}`,
      },
    };
    var data = "";
    const request = http.request(options, function (response) {
      response.on("data", function (chunk) {
        data += chunk;
      });
      response.on("end", function () {
        res.setHeader("content-type", "application/json");
        res.status(200).send(data);
      });
    });
    request.end();
  } catch (err) {
    console.log(err);
    res.status(500).send({
        message: "Internal Server Error. Please try again after sometime.",
      });
  }
});
app.post("/crmData", async (req, res) => {
  try {
    const catalystApp = catalyst.initialize(req);
    const createData = req.body;
    const reqData = [];
    reqData.push(createData);
    const data = {
      data: reqData,
    };
    if (!createData) {
      res.status(400).send({ message: "Data Not Found" });
    }
    const userDetails = await getUserDetails(catalystApp);
    const accessToken = await getAccessToken(catalystApp, userDetails);
    const options = {
      hostname: HOST,
      port: PORT,
      method: "POST",
      path: `/crm/v2/Leads`,
      headers: {
        Authorization: `Zoho-oauthtoken ${accessToken}`,
        "Content-Type": "application/json",
      },
    };
    const request = http.request(options, function (response) {
      res.setHeader("content-type", "application/json");
      response.pipe(res);
    });
    request.write(JSON.stringify(data));
    request.end();
  } catch (err) {
    console.log(err);
    res
      .status(500)
      .send({
        message: "Internal Server Error. Please try again after sometime.",
      });
  }
});
app.put("/crmData/:id", async (req, res) => {
  try {
    const catalystApp = catalyst.initialize(req);
    const updateData = req.body;
    const reqData = [];
    reqData.push(updateData);
    const data = {
      data: reqData,
    };
    if (!updateData) {
      res.status(400).send({ message: "Update Data Not Found" });
    }
    const userDetails = await getUserDetails(catalystApp);
    const accessToken = await getAccessToken(catalystApp, userDetails);
    const options = {
      hostname: HOST,
      port: PORT,
      method: "PUT",
      path: `/crm/v2/Leads/${req.params.id}`,
      headers: {
        Authorization: `Zoho-oauthtoken ${accessToken}`,
        "Content-Type": "application/json",
      },
    };
    const request = http.request(options, function (response) {
      res.setHeader("content-type", "application/json");
      response.pipe(res);
    });
    request.write(JSON.stringify(data));
    request.end();
  } catch (err) {
    console.log(err);
    res
      .status(500)
      .send({
        message: "Internal Server Error. Please try again after sometime.",
      });
  }
});
app.delete("/crmData/:id", async (req, res) => {
  console.log(`/crm/v2/Leads/${req.params.id}`);
  try {
    const catalystApp = catalyst.initialize(req);
    const userDetails = await getUserDetails(catalystApp);
    const accessToken = await getAccessToken(catalystApp, userDetails);
    const options = {
      hostname: HOST,
      port: PORT,
      method: "DELETE",
      path: `/crm/v2/Leads/${req.params.id}`,
      headers: {
        Authorization: `Zoho-oauthtoken ${accessToken}`,
        "Content-Type": "application/json",
      },
    };
    const request = http.request(options, function (response) {
      res.setHeader("content-type", "application/json");
      response.pipe(res);
    });
    request.end();
  } catch (err) {
    console.log(err);
    res.status(500).send({
        message: "Internal Server Error. Please try again after sometime.",
      });
  }
});
async function getAccessToken(catalystApp, userDetails) {
  const refresh_token = userDetails[0].Token.refresh_token;
  const userId = userDetails[0].Token.userId;
  const credentials = {
    [userId]: {
      client_id: CLIENTID,
      client_secret: CLIENT_SECRET,
      auth_url: AUTH_HOST,
      refresh_url: AUTH_HOST,
      refresh_token,
    },
  };
  const accessToken = await catalystApp.connection(credentials).getConnector(userId).getAccessToken();
  return accessToken;
}
async function getRefreshToken(code, res, domain) {
  try {
    const url = `${AUTH_HOST}?code=${code}&client_id=${CLIENTID}&client_secret=${CLIENT_SECRET}&grant_type=authorization_code&redirect_uri=${domain}/server/crm_crud/generateToken`;
	const response = await axios({
		method: "POST",
		url
	  });
    return response.data.refresh_token;
  } catch (err) {
    console.log(err);
    res.status(500).send({
        message: "Internal Server Error. Please try again after sometime.",
        error: err,
      });
  }
}
async function getUserDetails(catalystApp) {
  let userDetails = await catalystApp.userManagement().getCurrentUser();
  let userDetail = await catalystApp.zcql().executeZCQLQuery(`SELECT * FROM Token where UserId=${userDetails.user_id}`);
  return userDetail;
}
module.exports = app;
				
```

> **Note:** After you copy and paste this code in your function file, ensure that you replace the following values in it:

* [Client ID](https://docs.catalyst.zoho.com/en/tutorials/leadmanager/nodejs/register-client) in line 11
* [Client Secret](https://docs.catalyst.zoho.com/en/tutorials/leadmanager/nodejs/register-client) in line 12

The functions directory is now configured. We will discuss the function and client code, after you configure the client.