Dialogflow Integration with Express.js

Description

This project demonstrates how to integrate a Dialogflow agent with an Express.js server. The application allows users to send queries to a Dialogflow agent and receive responses via a RESTful API.

Features

• Query Dialogflow agent using REST API.
• Handle user queries and return bot responses.
• Use environment variables for configuration.

Prerequisites

1. Node.js (version 14 or higher recommended)
2. Dialogflow Agent created on Dialogflow Console.
3. Google Cloud Project with the following APIs enabled:
   • Dialogflow API
   • IAM & Admin API
4. Service Account Key JSON for authenticating with Google Cloud.
5. gcloud CLI (optional, for deployment to Google Cloud).

Installation

1. Clone this repository:

   git clone <repository-url>
   cd <repository-folder>

2. Install dependencies:

   npm install

3. Set up environment variables: Create a .env file in the root directory and add the following variables:

   PORT=7000
   PROJECT_ID=your-dialogflow-project-id
   CREDENTIALS_PATH=./credential.json

4. Add your Service Account Key JSON:

   • Download the JSON key from the Google Cloud Console.
   • Place the file in the project directory and name it credential.json (or update CREDENTIALS_PATH in .env).

Usage

Running Locally

1. Start the server:

   npm start

2. Send a GET request to the server:

   • URL: http://localhost:7000/?message=Your+Message

3. Example Response:

   {
       "message": "Success",
       "result": {
           "user": "Your Message",
           "bot": "Response from Dialogflow"
       }
   }

Deploying to Google Cloud Run

1. Authenticate with Google Cloud:

   gcloud auth login

2. Deploy the application:

   gcloud run deploy dialogflow-integration \
       --source . \
       --platform managed \
       --region <your-region> \
       --set-env-vars GOOGLE_APPLICATION_CREDENTIALS=/path/to/credential.json \
       --set-env-vars PROJECT_ID=your-dialogflow-project-id

3. Access the deployed service and query it via the URL provided by Cloud Run.

Project Structure

.
├── credential.json        # Service Account Key JSON (not included in repo)
├── .env                   # Environment variables
├── package.json           # Dependencies and scripts
├── app.js                 # Main server code
└── README.md              # Project documentation

Code Overview

Main Components

1. Dialogflow Integration

   • The runSample function interacts with Dialogflow API to send user queries and fetch bot responses.

   async function runSample(userMessage) {
       const sessionId = uuid.v4();
       const sessionClient = new dialogflow.SessionsClient();
       const sessionPath = sessionClient.sessionPath(projectId, sessionId);
   
       const request = {
           session: sessionPath,
           queryInput: {
               text: {
                   text: userMessage,
                   languageCode: 'en-US',
               },
           },
       };
   
       const responses = await sessionClient.detectIntent(request);
       return {
           user: responses[0].queryResult.queryText,
           bot: responses[0].queryResult.fulfillmentText,
       };
   }

2. Express.js Server

   • A simple Express server exposes an API endpoint to handle user queries.

   app.get("/", async (req, res) => {
       try {
           const userMessage = req.query.message;
           const result = await runSample(userMessage);
           return res.status(200).json({ message: "Success", result });
       } catch (error) {
           console.error(error);
           return res.status(500).json({ message: "Server error", error });
       }
   });

Troubleshooting

1. Malformed Request Error (400)

   • Ensure that userMessage is not empty or null.
   • Validate GOOGLE_APPLICATION_CREDENTIALS path and PROJECT_ID.

2. Environment Variable Issues

   • Confirm that .env file is properly configured and loaded.

3. Dialogflow API Error

   • Check Google Cloud Logs for more details: Logs Explorer.

Cloud Computing's Team

Name	Bangkit ID	University
Arifatus Fitriani	C296B4KX0643	Universitas Pembangunan Nasional Veteran Jawa Timur
Mochammad Irfan Efendi	C202B4KY2532	Universitas Dr Soetomo