Quick Start

Generate an ID

Import id and call it with a prefix. That's the whole API for the common case.

import { id } from "prefid";

const userId = id("user");
// => "user_a8Kd0f2bQ1nR7pZ3xW4mT6y"

const orderId = id("order");
// => "order_9f8e7d6c5b4a3F2e1D0cB9aX"

const { id } = require("prefid");

const userId = id("user");
// => "user_a8Kd0f2bQ1nR7pZ3xW4mT6y"

const orderId = id("order");
// => "order_9f8e7d6c5b4a3F2e1D0cB9aX"

The prefix is type-safe

The return value isn't just string — it's a template literal type that remembers the prefix. This is what stops you from mixing up ID types.

const userId = id("user");
//    ^? type: `user_${string}`

function getUser(id: `user_${string}`) { /* ... */ }

getUser(userId);        // ✅ ok
getUser(id("order"));   // ❌ compile error — that's an order id

Configure defaults

Use createId to set the size, separator, or alphabet once and reuse the generator across your app.

import { createId } from "prefid";

// Configure once, reuse everywhere.
const id = createId({ size: 16 });

id("user"); // => "user_a1b2c3d4e5f6g7h8"

const { createId } = require("prefid");

// Configure once, reuse everywhere.
const id = createId({ size: 16 });

id("user"); // => "user_a1b2c3d4e5f6g7h8"

What's next?

• id() — the full reference for the default generator.
• ensureUnique() — guarantee an ID is free in your database.
• Uniqueness & Collisions — how safe these IDs really are.