Describe the problem

Summary

I am using queryParameters as a way to search and filter data on my website. However, sometimes additional parameters (like UTM tags or other tracking query params) get added to the URL. Currently, these extra params are also parsed, which makes it harder to work only with the parameters I’ve defined.

Problem

I want to be able to parse the query string and only extract the keys/values that I’ve explicitly set in queryParameters. At the moment, there’s no built-in way to ignore unknown parameters.

Describe the proposed solution

Introduce an option (or utility) that:

• Parses the query string.
• Returns only the keys that match those defined in queryParameters.
• Outputs a clean JSON object with just the relevant values.

Example

// Suppose I define:
const params = queryParameters({
  q: ssp.string(),
  page: ssp.number(),
});
let parsed = $derived(params.$parsed)

// URL contains:
?q=svelte&page=2&utm_source=google

// Desired result of parsed:
{ q: "svelte", page: 2 }

Benefits

• Cleaner query parsing.
• Prevents noise from unrelated query parameters (UTM, tracking, etc.).
• Makes filtering and searching more predictable.