qskit

Tiny, type-safe query string parse & stringify — multiple array formats (bracket / index / comma / repeat) and number/boolean coercion. Zero dependencies.

URLSearchParams is fine until you need arrays as tags[]=a&tags[]=b, numbers that come back as numbers, or stable sorted output. qskit gives you parse and stringify with the array conventions every backend uses and optional type coercion — symmetric, predictable, and zero-dependency.

import { parse, stringify } from "@billdaddy/qskit";

parse("a=1&a=2&page=3");          // { a: ["1", "2"], page: "3" }
stringify({ tags: ["x", "y"] });  // "tags=x&tags=y"

Why qskit?

• Symmetric parse / stringify. The same arrayFormat round-trips cleanly.
• Every array convention. "none" (repeat keys), "bracket" (a[]=), "index" (a[0]=), "comma" (a=1,2).
• Optional coercion. parseNumbers and parseBooleans turn "42"/"true" into 42/true.
• Sensible encoding. Proper percent-encoding, + decoded to space, array brackets kept readable.
• Null/undefined handling. undefined is dropped; null becomes a bare key (or dropped with skipNull).
• Typed & tiny. Full types, ESM + CJS, zero dependencies.

Install

npm install @billdaddy/qskit
# or: pnpm add @billdaddy/qskit  /  yarn add @billdaddy/qskit  /  bun add @billdaddy/qskit

parse(input, options?)

import { parse } from "@billdaddy/qskit";

parse("?a=1&b=2");                 // { a: "1", b: "2" } (leading ?/# ignored)
parse("a=1&a=2");                  // { a: ["1", "2"] }
parse("q=hello+world");            // { q: "hello world" }

parse("ids[]=1&ids[]=2", { arrayFormat: "bracket" }); // { ids: ["1", "2"] }
parse("a[0]=x&a[1]=y", { arrayFormat: "index" });     // { a: ["x", "y"] }
parse("a=1,2,3", { arrayFormat: "comma" });           // { a: ["1", "2", "3"] }

parse("n=42&ok=true", { parseNumbers: true, parseBooleans: true });
// { n: 42, ok: true }

interface ParseOptions {
  arrayFormat?: "none" | "bracket" | "index" | "comma"; // default "none"
  parseNumbers?: boolean;   // default false
  parseBooleans?: boolean;  // default false
}

stringify(object, options?)

import { stringify } from "@billdaddy/qskit";

stringify({ a: 1, b: "x", c: true });              // "a=1&b=x&c=true"
stringify({ ids: [1, 2] });                        // "ids=1&ids=2"
stringify({ ids: [1, 2] }, { arrayFormat: "bracket" }); // "ids[]=1&ids[]=2"
stringify({ ids: [1, 2] }, { arrayFormat: "comma" });   // "ids=1,2"
stringify({ c: 3, a: 1 }, { sort: true });         // "a=1&c=3"
stringify({ a: 1, b: undefined });                 // "a=1"

interface StringifyOptions {
  arrayFormat?: "none" | "bracket" | "index" | "comma"; // default "none"
  sort?: boolean;     // default false
  skipNull?: boolean; // default false (null → bare key)
}

Contributors ✨

This project follows the all-contributors specification. Contributions of any kind are welcome — code, docs, bug reports, ideas, reviews! See the emoji key for how each contribution is recognized, and open a PR or issue to get involved.

Thanks goes to these wonderful people:

License

MIT © Tung Tran