Pre-Request Scripting

Pre-Request Scripts allow you to execute code before each HTTP request, making them ideal for tasks such as authentication, request headers manipulation, and setting up a consistent environment before fetching data from an external API. By incorporating pre-request scripts, you can streamline your request handling process and ensure consistent behavior across various endpoints.

1.Reading Environment Variables

You can access environment variables using the following syntax:

 
const myVariable = theneo.variables["variable-name"];

2. Reading Endpoints

To retrieve endpoints, use the following code:

 
const myEndpoint = theneo.endpoints;

3. Reading Parameters

Access parameters in your pre-request script using:

 
const myParameter = theneo.parameters;

4. Reading Query Parameters

To access query parameters, use the following syntax:

 
const myQueryParameter = theneo.queryParameters;

5. Reading Header Variables

Header variables can be accessed as follows:

 
const myHeader = theneo.headers["header-name"];

6. Setting Header Values

You can modify or set new header values with the following command:

 
theneo.headers["header-name"] = "header value";

7. Reading Request Body

To access the request body in JSON format, use:

 
const requestBody = theneo.requestBody.json;

8. Sending Requests within Pre-Request Scripts

You can send requests to other endpoints using the fetch API or similar methods. For instance, setting an Authorization header might look like this:

 
const token = theneo.variables["authToken"];
theneo.headers["Authorization"] = Bearer ${token};

9. Example Script

Here’s a complete example of a pre-request script that generates an HMAC signature and sets custom headers:

 
const apiKey = theneo.variables["apiKey"];
const apiSecret = theneo.variables["apiSecretKey"];
const timestamp = new Date().getTime();
console.log("API Key:", apiKey);
console.log("API Secret:", apiSecret);
console.log("Timestamp:", timestamp);
const requestData = JSON.stringify(theneo.requestBody.json);
const rawSignature = ${apiKey}:${timestamp}:${requestData};
function generateHMAC(rawSignature, secret) {
const signature = CryptoJS.HmacSHA256(rawSignature, secret);
return CryptoJS.enc.Hex.stringify(signature);
}
const signature = generateHMAC(rawSignature, apiSecret);
theneo.headers = {
"API-Key": apiKey,
"Timestamp": timestamp.toString(),
"Signature": signature,
"Content-Type": "application/json",
"Accept": "/"
};
console.log("Headers set for request:", theneo.headers);

Available Libraries

Running Your Script

Reading External Query Parameters

To authenticate users in your API explorer by reading and using externally passed query parameters, such as ?my_token=<token>and utilizing them in the pre-request script context.

Steps to Implement

https://api-explorer.yoursite.com?myToken=<token> 

Setting up a Dynamic Base URL in API Explorer

The goal is to allow users to overwrite the default base URL from the API Explorer with a custom base URL set through a new field. This enables requests to be sent to a dynamic base URL specified by the user instead of a predetermined one.

 
theneo.baseUrl = theneo.variables["baseURL"];