Socket.IO

Socket.IO is a library that enables low-latency, bidirectional, and event-based communication between clients and servers. It provides real-time, two-way communication channels over WebSocket connections with automatic fallback to HTTP long-polling when WebSocket is unavailable.

Prerequisites

Apidog version 2.7.0 or later

A Socket.IO server endpoint (supports ws:// and wss:// protocols)

Creating a Socket.IO Endpoint

Create a new Socket.IO endpoint

Hover over the "+" button on the left panel of your project

Click on "New Socket.IO"

Enter the server address

Input the server address (e.g., ws://localhost:3000)

Supports both ws:// and wss:// protocols

Establish connection

Click the "Connect" button to connect to the server

Listening to Events

Open the Events tab and enter the event name you want to listen to (e.g., new message). Disable Listen for a specific event to stop receiving messages for that event.

Event Listening Rules

Rule	Description
Default Event	System listens to the `message` event by default
Dynamic Changes	Adding or removing events does not affect existing connections
Event Name Changes	Changing an event name automatically stops listening to the original event

Sending Messages

Events & Arguments

Set up events and arguments

Event: Defaults to message, but you can customize it (e.g., new message)

Argument: Supports JSON, text, and Binary formats

Send the message

Click the "Send" button

View records

Check the timeline for sending records with event tags

Acknowledgment (Ack)

When you enable the Ack option, the server sends back a callback message after receiving and processing the request.

Multiple Arguments

Click "+ Add Argument" to include additional arguments.

When you send a message with multiple arguments, the timeline displays a label like "x Args". Click on it to expand and view all arguments. Switch between tabs on the right for more details.

Handshake Request Parameters

You can include request parameters in the URL, Params, Headers, or Cookies.

Client Version and Handshake Path

Configuration Entry

Go to Settings under Request

Client Version

The default is v4. If the server uses an older version (e.g., v2/v3), manually switch the client version

Handshake Path

The default is /socket.io. If the server uses a custom path (e.g., /custom), update the path accordingly

Using Variables

Apidog enables you to include variables in your arguments. When you send a message, these variables are automatically replaced with their real values.

Saving the Endpoint

Once debugging is complete, click the "Save" button to store the Socket.IO endpoint in the HTTP project's folder tree. This makes it easy for team members to access, debug, and view the endpoint documentation, improving collaboration and efficiency.

Generating Endpoint Documentation

Easily manage your Socket.IO endpoint by setting its status, assigning a maintainer, and adding relevant tags. You can also write detailed descriptions using Markdown. With Apidog, you can generate online API documentation and share the URL with your team for seamless collaboration.

FAQs

What to do if the connection fails?

Checklist:

Make sure the server is running

Verify that the client version is compatible with the server

Ensure the firewall isn't blocking the required port

Not receiving all arguments?

ACK Not Triggered?

Prerequisites#

Creating a Socket.IO Endpoint#

Listening to Events#

Event Listening Rules#

Sending Messages#

Events & Arguments#

Acknowledgment (Ack)#

Multiple Arguments#

Handshake Request Parameters#

Client Version and Handshake Path#

Using Variables#

Saving the Endpoint#

Generating Endpoint Documentation#

FAQs#