Request Body - Atrahasis Guide

Body Tab

The Body tab configures the data sent with your request. Not all HTTP methods use a body—GET, HEAD, and OPTIONS typically do not, while POST, PUT, and PATCH require one. DELETE may optionally include a body depending on the API.

Body Type Selector

The dropdown in the top-right corner of the Body tab determines how your data is formatted and which Content-Type header is sent.

Type	Content-Type Header	Use Case
none	Not sent	Requests without a body (GET, HEAD, OPTIONS)
JSON	application/json	REST APIs, structured data
XML	application/xml	SOAP APIs, legacy systems
Text	text/plain	Plain text, custom formats
form-data	multipart/form-data	File uploads, mixed content
x-www-form-urlencoded	application/x-www-form-urlencoded	HTML form submissions
Binary	Auto-detected from file	Single file upload as raw bytes

JSON Body

The most common format for modern REST APIs. The editor provides syntax highlighting and real-time validation.

Example

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

Validation

Invalid JSON is highlighted with warning markers in the editor. A message appears at the bottom describing the syntax error and its location.

Missing commas between properties
Trailing commas (not allowed in JSON)
Unquoted keys
Single quotes instead of double quotes
Mismatched brackets or braces

Format and Minify

Hover over the editor to reveal action buttons in the top-right corner:

Copy — Copies the entire body to clipboard
Format — Pretty-prints the JSON with proper indentation
Minify — Removes whitespace to create a compact single line

Note: JSON with syntax errors can still be sent—Atrahasis does not prevent sending invalid JSON. The server will reject it and return an error response.

XML Body

Used for SOAP APIs and systems that require XML format. The editor provides XML syntax highlighting.

Example

<?xml version="1.0" encoding="UTF-8"?>
<user>
  <name>John Doe</name>
  <email>[email protected]</email>
  <age>30</age>
</user>

Format and Minify buttons work the same as JSON—hover over the editor to access them.

Text Body

Plain text format for custom content types or raw data. No structured-syntax validation is performed (there is no JSON or XML parser running over the body), but random variable syntax is still checked — invalid {{random.*}} expressions show an error message beneath the editor. Format and Minify buttons are hidden for Text bodies; the Copy button is still available on hover.

Use Cases

GraphQL queries (when not using the GraphQL panel)
Custom text-based protocols
Debug logging
Webhook payloads with custom formats

Form Data (multipart/form-data)

Used for file uploads or when sending mixed content types. Each field can be either text or a file.

Field Table

The form-data editor displays a table with the following columns:

Column	Description
Checkbox	Enable/disable the field without deleting
Key	The field name (form input name)
Value/File	Text value or file selector depending on type
Type	Toggle between Text and File
Delete	Remove the field

File Upload

When type is set to File, click the Select File button to choose a file from your system. The selected file's name is displayed in the Value cell; hover over it to see the full absolute path as a tooltip. The file's MIME type is automatically detected from the file extension and emitted as a Content-Type header inside that file's form-data part when the request is sent.

Multiple files: Add multiple rows with type "file" to upload multiple files in a single request.

URL Encoded (x-www-form-urlencoded)

Traditional HTML form encoding. Data is sent as key-value pairs encoded in the URL format.

How It Works

Your key-value entries are converted to the format:

key1=value1&key2=value2&key3=value3

Special characters are percent-encoded (e.g., spaces become %20 or +).

When to Use

OAuth token requests
Legacy APIs expecting form data
Simple key-value submissions without files

Difference from form-data: URL-encoded cannot include files and has a size limit (varies by server, typically ~2KB for URL, larger for body). Use form-data for file uploads.

Binary

Sends a single file as the raw request body. Unlike form-data, the file content is sent directly without any encoding or wrapping.

How It Works

Click Click to select a file to open the system file picker
After selection, the file name is shown prominently and the full absolute path appears below it in a smaller muted line
The Content-Type header is automatically detected from the file extension
When the request is sent, the raw file bytes become the request body
Click Remove file to clear the selection and choose a different file

MIME Type Detection

Common file types and their detected Content-Type:

.png → image/png

.jpg → image/jpeg

.pdf → application/pdf

.zip → application/zip

.csv → text/csv

.mp4 → video/mp4

When to Use

Image upload APIs (avatar, thumbnail)
Document processing services
Streaming media uploads
APIs that expect raw file content without form encoding

None

Select "none" when the request should not include a body. This is the default for GET, HEAD, and OPTIONS methods. The editor displays a message indicating no body will be sent, and no Content-Type header is added.

Using Variables in Body

You can use environment variables and random variables within JSON, XML, or Text bodies.

Environment Variables

{
  "api_key": "{{apiKey}}",
  "user_id": "{{userId}}",
  "base_url": "{{baseUrl}}"
}

Values are replaced from the active environment when the request is sent.

Random Variables

{
  "id": "{{random.uuid}}",
  "email": "{{random.email}}",
  "timestamp": {{random.timestamp}}
}

Random variables (prefixed with random.) generate new values on each request. See the Random Variables section for the complete list.

Validation: Invalid random variable syntax is highlighted in the editor with an error message.

Request Line Params