How to Set Value in Deno KV: Simple Guide with Examples

To set a value in Deno KV, use the kv.set() method with a key array and the value you want to store. For example, await kv.set(["myKey"], "myValue") saves the value under the key myKey.

Syntax

The kv.set() method stores a value in Deno KV. It takes two main parts:

• Key: An array of strings or numbers that uniquely identifies the entry.
• Value: Any JSON-serializable data you want to save.

You must await the kv.set() call because it is asynchronous.

typescript

await kv.set(["key1", "key2"], "value")

Example

This example shows how to open a Deno KV store, set a value, and then confirm it was saved by retrieving it.

typescript

import { openKv } from "https://deno.land/x/kv/mod.ts";

const kv = await openKv();

// Set a value with key ["user", "123"]
await kv.set(["user", "123"], { name: "Alice", age: 30 });

// Get the value back
const result = await kv.get(["user", "123"]);
console.log(result.value);

Output

{"name":"Alice","age":30}

Common Pitfalls

Some common mistakes when setting values in Deno KV include:

• Not using an array for the key. The key must always be an array, even if it has one element.
• Forgetting to await the kv.set() call, which can cause unexpected behavior.
• Trying to store non-serializable values like functions or symbols, which will cause errors.

typescript

/* Wrong: key is a string, not an array */
// await kv.set("user123", "value"); // ❌

/* Right: key is an array */
await kv.set(["user123"], "value"); // ✅

Quick Reference

Remember these tips when setting values in Deno KV:

• Use await kv.set(keyArray, value).
• Key must be an array of strings or numbers.
• Value must be JSON-serializable.
• Always handle asynchronous calls properly.

Key Takeaways

Always use an array as the key when calling kv.set().

Await the kv.set() method because it is asynchronous.

Store only JSON-serializable values to avoid errors.

Use kv.get() to verify your value was saved correctly.

Deno KV keys can be multi-part arrays for better organization.