Assertions vs pre and post scripts

Source: Dev.to

Simple Assertions vs Pre & Post Requests

Many developers already use Assertions in Voiden to validate responses—checking status codes, verifying fields, or ensuring data formats.
They are great for simple validation and quick checks after a request.

But what if your workflow needs more than validation? That’s where Pre‑ & Post‑request scripts come in.

Pre‑request scripts

Run before the request to:

• Generate tokens
• Set dynamic headers
• Compute values
• Inject variables
• Prepare data on the fly

Post‑request scripts

Run after the response to:

• Validate responses (beyond simple assertions)
• Extract values and store variables
• Trigger follow‑up logic
• Chain multiple requests together

When to use Assertions

• Simple checks and validations
• Fast feedback
• Lightweight workflows

When to use Pre‑ & Post‑request scripts

• Dynamic APIs (e.g., token rotation)
• Multi‑step flows and automated chaining
• Scenarios requiring complex logic

Use assertions for quick checks and scripts for dynamic, automated workflows.

Voiden now supports JavaScript and Python for Pre‑ & Post‑request scripts (available in the beta).

Question for the community: Which other languages would you like to see supported in Voiden? Your feedback could shape the next updates!

Beta download:
GitHub repository: