Most developers use VS Code as development tool. The REST Client is a popular VS Code extension to help developers send and receive HTTP requests/responses with ease. It is exceptionally useful in testing API calls for different protocols supported by Chainstack. Before you begin, ensure you have the following:

• A Chainstack account (with a deployed node);
• Visual Studio Code installed

Installation

1. Open VS code, click on extension logo in the left panel.
2. Search for rest-client in search bar and select it from the list.
3. In the page opened, click Install.
4. Restart VS Code, the extension should be ready to use.

How to use it

Open VS Code and create a new HTTP file. Type in:

chainstack.com

A small line of text Send Request appear on top of the line, it means the extension is successfully installed.

There are four ways to send an HTTP request.

1. Click the Send Request link above the request (this will appear if the file's language mode is HTTP).
2. Use Ctrl+Alt+R (Cmd+Alt+R for macOS).
3. Right-click and then select Send Request.
4. Press F1 and then select/type Rest Client: Send Request.

If the request is valid, a response is returned. Text in the response is formatted and colour coded for readability.

Using it with Chainstack endpoint

A typical Chainstack blockchain endpoint is in the format of:

https://nd-123-456-789.p2pify.com/3c6e0b8a9c15224a8228b9a98ca1531d

Using Ethereum mainnet elastic node as example, paste the code into VS Code. (Change the endpoint address.)

GET https://nd-123-456-789.p2pify.com/3c6e0b8a9c15224a8228b9a98ca1531d HTTP/1.1
content-type: application/json
{
  "jsonrpc": "2.0", 
  "method": "eth_chainId", 
  "params": [], 
  "id": 0 
}

This should return:

Using it with GraphQL endpoint

Copy the code to see it in action. The authorization field and URL needs to be changed.

POST https://nd-123-456-789.p2pify.com//graphql
Content-Type: application/json
Authorization: Basic username:password
X-REQUEST-TYPE: GraphQL
query{ 
  block{ 
   number 
   hash 
  } 
}

The response:

Sample code with variables and delimiter

Another useful feature in REST Client is the delimiter. In VS Code, different requests can be store in the same file and separated with ###.

REST Client supports variables too. Variables, file variable to be more specific because REST Client supports 3 types of variables, are declared with @ sign and reference with {{}}. Copy the code below to see it in action.

###
@url = https://nd-123-456-789.p2pify.com/3c6e0b8a9c15224a8228b9a98ca1531d
@contentType = application/json

###
GET {{url}} HTTP/1.1
content-type: {{contentType}}

{ 
  "jsonrpc": "2.0", 
  "method": "eth_chainId", 
  "params": [], 
  "id": 0 
}

###
GET {{url}} HTTP/1.1
content-type: {{contentType}}

{ 
  "jsonrpc": "2.0", 
  "method": "eth_syncing", 
  "params": [], 
  "id": 0 
}

###