Prompt Variables

Overview

Prompt variables are ephemeral variables in Bruno that allow you to provide values interactively at the time a request is executed. Unlike other variable types, prompt variables do not have predefined values and are not persisted. They exist only for the duration of a single request execution.

Prompt variables are ideal for:

• Sensitive data you don’t want to save in your collection
• Ad-hoc values that change frequently
• Scenarios where you want to manually provide input before sending a request

Syntax

Prompt variables use the following syntax:

• The ? indicates this is a prompt variable
• The text after ? is the message shown to you in the prompt dialog

Prompt variables are highlighted in blue in the Bruno UI.

Using Prompt Variables

You can use prompt variables anywhere markup variables are supported in Bruno, including:

• URLs and query parameters
• Headers
• Request bodies
• Authentication fields

How It Works

When you execute a request containing prompt variables, Bruno displays a modal dialog listing all prompt variables with their prompt messages. You provide values for each variable before the request is sent.

Example:

If your request body contains a prompt variable like {{?Prompt Var}}:

{
  "title": "{{?Prompt Var}}"
}

Bruno will display a prompt dialog asking for “Prompt Var” before sending the request.

Deduplication

If you use the same prompt variable (like {{?Username}}) multiple times in a request, Bruno will only prompt you once and substitute the value everywhere it appears.

Example:

{
  "user": "{{?Username}}",
  "profile": {
    "name": "{{?Username}}"
  }
}

You will only be prompted for “Username” once, and the value will be used in both locations.

Edge Cases

Empty Values:
If you leave a prompt variable blank (without entering any value), it will be replaced with an empty string in the request.

Canceling the Prompt:
If you cancel the prompt dialog, the request will not be sent.

Behavior in Automated Environments

When running collections via Bruno CLI or the Collection Runner, any requests containing prompt variables will be skipped and marked as skipped in the output. This is because these automated environments do not support interactive prompting.

Viewing Prompt Variables

Prompt variables are ephemeral and only exist during request execution. They are not displayed in the variables viewer and are not accessible in scripts (pre-request or post-response scripts).