> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getpostchi.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Request body

> Send JSON, form-encoded, multipart, and plain text bodies using the @body directive in your request files.

Add a body to a request by placing `@body` on its own line. Everything after `@body` is sent as the request body.

```http theme={null}
POST https://api.example.com/resource
Content-Type: application/json
@body
{
  "key": "value"
}
```

Postchi determines how to encode the body from the `Content-Type` header when present, or by inspecting the body text when it isn't.

***

## JSON body

Postchi treats the body as JSON when:

* `Content-Type: application/json` is set, or
* the body starts with `{` or `[`

```http theme={null}
POST https://api.example.com/users
Content-Type: application/json
@body
{
  "name": "<username>",
  "role": "admin"
}
```

Variables inside JSON bodies must be written as quoted string values. Postchi replaces `"<username>"` with the resolved value and keeps the surrounding quotes so the JSON stays valid.

***

## Form body (URL-encoded)

Postchi treats the body as URL-encoded form data when:

* `Content-Type: application/x-www-form-urlencoded` is set, or
* the body uses `key=value` pairs

```http theme={null}
POST https://api.example.com/login
Content-Type: application/x-www-form-urlencoded
@body
username=<username>
password=<password>
```

Each line is a separate form field. Variables work as values here too.

***

## Multipart form body (file uploads)

Use `Content-Type: multipart/form-data` together with `readFile()` to attach binary files:

```http theme={null}
POST https://api.example.com/upload
Content-Type: multipart/form-data
@body
file=readFile(/path/to/document.pdf)
name=<doc_name>
```

`readFile(path)` reads the file from disk and attaches it as a binary form part. If you don't set `Content-Type` explicitly, Postchi automatically switches to `multipart/form-data` when it encounters a `readFile()` call in the body.

<Note>
  `readFile()` is only valid inside a form body. To inline a text file as the entire body, use `readText()` instead.
</Note>

***

## Plain text and other content types

Any `Content-Type` that isn't JSON or form-encoded is sent as a plain text body:

```http theme={null}
POST https://api.example.com/events
Content-Type: text/plain
@body
This is a plain text body.
```

***

## Loading the body from a file

For large bodies, keep the content in a separate file and use `readText(path)` to load it at run time:

```http theme={null}
POST https://api.example.com/batch
Content-Type: application/json
@body
readText(/path/to/large-payload.json)
```

***

## Variables in bodies

Variables (`<variable_name>`) work in all body types:

<Tabs>
  <Tab title="JSON">
    ```http theme={null}
    POST https://api.example.com/orders
    Content-Type: application/json
    @body
    {
      "user_id": "<user_id>",
      "product": "<product_id>"
    }
    ```
  </Tab>

  <Tab title="Form">
    ```http theme={null}
    POST https://api.example.com/subscribe
    Content-Type: application/x-www-form-urlencoded
    @body
    email=<email>
    plan=<plan_name>
    ```
  </Tab>

  <Tab title="Plain text">
    ```http theme={null}
    POST https://api.example.com/messages
    Content-Type: text/plain
    @body
    Hello, <username>. Your code is <activation_code>.
    ```
  </Tab>
</Tabs>

Values are substituted from the active environment when the request runs. If a variable is missing, Postchi shows an error before sending.