Parameters and Body Data

Parameters and request bodies allow you to send data with your API requests. This guide covers query parameters, path variables, and different request body formats.

Path Variables

Path variables allow you to define dynamic segments in your API URL using the :variableName syntax. This is useful for RESTful APIs where resource identifiers are part of the URL path. For example, if your API endpoint is:

https://api.example.com/users/:userId/posts/:postId

Requestly automatically detects the path variables (:userId and :postId) from the URL and displays them in the Params tab under Path Variables. You can then set values for each variable:

Key	Value	Description
userId	123	The user’s unique identifier
postId	456	The post’s unique identifier

When you send the request, Requestly compiles the URL with your provided values:

https://api.example.com/users/123/posts/456

Path variables are automatically extracted from your URL. Simply type a URL with :variableName segments, and they’ll appear in the Path Variables table for you to fill in.

Query Parameters

In the Query Params section, you can add query parameters as key-value pairs to send extra information with the URL. To add more parameters, click on the + Add More button. Each query parameter consists of:

Key: The parameter name
Value: The parameter value
Type: An enum to enforce the value type
Description (optional): Internal documentation explaining the purpose of the parameter

For example:

Adding uid=123 to https://app.requestly.io/echo results in: https://app.requestly.io/echo?uid=123

The checkboxes next to each parameter let you include or exclude them without deleting them. For instance, if you uncheck a parameter, the final URL will not include it.

Bulk Edit Query Parameters

You can also manage query parameters using Bulk Edit. This allows you to add or update multiple parameters at once in a key:value format.

Add one parameter per line
Separate keys and values using a colon :
Prefix any line with // to disable that parameter

Bulk Edit is useful when working with a large number of query parameters or when making quick mass updates. Example:

page:1
limit:50
sort:desc
// filter:active

Request Body

For POST, PUT, or PATCH requests, use the Body tab to send data to the server. Requestly supports multiple body formats to accommodate different API requirements.

Supported Body Types

RAW (JSON/Text)
x-www-form-urlencoded
multipart/form-data
GraphQL

Send raw data as plain text or structured JSON.When to use:

Sending JSON data to REST APIs
Posting XML or plain text
Sending custom formatted data

You can select the language format:

JSON – for structured data like API payloads
Text – for plain string or unstructured data
XML – for XML-based APIs
HTML – for HTML content
JavaScript: for JavaScript payloads

Example JSON:

{
  "name": "John Doe",
  "email": "[email protected]",
  "age": 30,
  "active": true
}

Sends data as URL-encoded key-value pairs. This format is commonly used for HTML form submissions.When to use:

Traditional web form submissions
Simple key-value data
APIs that expect form data

Each field consists of:

Key: Field name
Value: Field value
Description: Optional documentation

Example:

username=johndoe
password=secret123
remember=true

Used when uploading files along with form fields. Each field is sent as a separate part of the request body.When to use:

Uploading images, documents, or files
Sending files with metadata
Form submissions with file attachments

Each field can be either:

Text field: Regular key-value pair
File field: File upload with browse button

Example use case: Uploading a user profile picture with name and bio

Per-field Content-Type

Each row has a Content-Type column. It sets the Content-Type header of that one part. Text rows and file rows both support it.Use it when an API needs a typed part. The common case is one JSON metadata part plus one file part in the same request:

Key	Type	Value	Content-Type
`metadata`	Text	`{"title":"Q3 contract"}`	`application/json`
`file`	File	`contract.pdf`	`application/pdf`

That request goes on the wire as:

--BOUNDARY
Content-Disposition: form-data; name="metadata"
Content-Type: application/json

{"title":"Q3 contract"}
--BOUNDARY
Content-Disposition: form-data; name="file"; filename="contract.pdf"
Content-Type: application/pdf

<file bytes>
--BOUNDARY--

BOUNDARY is the delimiter Requestly generates. It also appears in the request-level Content-Type header, as multipart/form-data; boundary=BOUNDARY.

Leave the field empty to use the default. The placeholder shows Auto. An empty value on a text row sends no Content-Type header for that part. An empty value on a file row sends application/octet-stream.

Requestly does not validate the value. You can enter any string, including an invalid MIME type, because a wrong content type is sometimes the case under test.Postman imports and exports carry this field on text rows, so the value survives a round-trip. File rows are a separate matter: Requestly cannot export the local file itself, so re-attach files after an import.Generated code snippets carry the value in curl: each typed part gains ;type=<value> in its --form argument. Other snippet languages follow their generator’s capability. python/requests keeps the type on file parts and drops it on text parts. Most other languages do the same. A few drop it on both parts, and a few keep it on both. Check the generated snippet before you rely on it for a typed part.

Autogenerated Headers

Requestly will automatically add certain headers to your requests based on your request body selections. When you add a request body, Requestly automatically sets the appropriate Content-Type header:

Body Type	Content-Type Header
RAW (JSON)	`application/json`
RAW (Text)	`text/plain`
RAW (XML)	`application/xml`
RAW (HTML)	`text/html`
RAW (JavaScript)	`application/javascript`
x-www-form-urlencoded	`application/x-www-form-urlencoded`
multipart/form-data	`multipart/form-data`

You can view and override the autogenerated headers in the Headers tab. These headers are automatically managed by Requestly to ensure your requests are properly formatted.

What’s Next?

Configure Headers

Add authentication and custom headers to your requests

Add Authorization

Set up API authentication methods

Use Variables

Make your requests dynamic with variables

Getting Started

Mock Server

Collaboration & Projects

Account & Administration

Parameters and Body Data

Path Variables

Query Parameters

Bulk Edit Query Parameters

Request Body

Supported Body Types

Per-field Content-Type

Autogenerated Headers

What’s Next?

Configure Headers

Add Authorization

Use Variables

​Path Variables

​Query Parameters

​Bulk Edit Query Parameters

​Request Body

​Supported Body Types

​Per-field Content-Type

​Autogenerated Headers

​What’s Next?

Configure Headers

Add Authorization

Use Variables

Path Variables

Query Parameters

Bulk Edit Query Parameters

Request Body

Supported Body Types

Per-field Content-Type

Autogenerated Headers

What’s Next?