Dynamic NASA Credentials with n8n Expressions

This n8n workflow showcases how to dynamically set credentials using expressions. It starts with a Form Trigger that collects a NASA API key from the user. The key is then injected into the NASA node's credential via an expression: {{ $json["Enter your NASA API key"] }}. Finally, it fetches the Astronomy Picture of the Day and redirects the user to the image URL via Respond to Webhook.

The primary benefit is flexibility in authentication—ideal for testing APIs or sharing workflows without exposing credentials. It eliminates hardcoded secrets, enhancing security and reusability across environments. Setup is straightforward: create a NASA credential, enable expression mode for the API key field, and input the expression.

Use cases include API testing demos, educational tutorials for n8n users, or prototyping dynamic auth for other services like Stripe or OpenAI. It's perfect for developers onboarding to n8n, teaching expressions, or building user-facing tools requiring temporary credentials. Extend it by swapping NASA for any expression-compatible node.