How to List Values in Deno KV: Syntax and Example

To list values in Deno KV, use the kv.list() method with an optional key prefix or range. This returns an async iterator over key-value pairs, which you can loop through with for await to access stored values.

Syntax

The kv.list() method retrieves entries from the Deno KV store. You can pass a key prefix or a range to filter keys.

• kv.list(prefixOrRange): Returns an async iterator of entries matching the prefix or range.
• prefixOrRange: Optional. A key prefix array or a range object to specify which keys to list.
• Each entry is an object with key and value properties.

typescript

const iterator = kv.list(['user']);
for await (const entry of iterator) {
  console.log(entry.key, entry.value);
}

Example

This example shows how to store some values in Deno KV and then list all values with a common prefix.

typescript

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

const kv = await openKv();

// Store some user data
await kv.set(['user', '1'], { name: 'Alice', age: 30 });
await kv.set(['user', '2'], { name: 'Bob', age: 25 });
await kv.set(['user', '3'], { name: 'Carol', age: 28 });

// List all users
console.log('Listing users:');
for await (const entry of kv.list(['user'])) {
  console.log(entry.key, entry.value);
}

Output

Listing users:
["user", "1"] { name: 'Alice', age: 30 }
["user", "2"] { name: 'Bob', age: 25 }
["user", "3"] { name: 'Carol', age: 28 }

Common Pitfalls

1. Forgetting to use for await when iterating the async iterator will cause errors.

2. Using incorrect key prefixes or ranges can return no results.

3. Not awaiting kv.set() before listing may cause missing entries.

typescript

/* Wrong: missing await in for loop */
const iterator = kv.list(['user']);
for (const entry of iterator) {
  console.log(entry.key, entry.value); // Error: iterator is async
}

/* Right: use for await */
for await (const entry of kv.list(['user'])) {
  console.log(entry.key, entry.value);
}

Quick Reference

• kv.list(prefix): List entries with keys starting with prefix.
• for await (const entry of kv.list(...)): Iterate async entries.
• entry.key: The key array of the entry.
• entry.value: The stored value.

Key Takeaways

Use kv.list() with a key prefix to get an async iterator of matching entries.

Always use for await to loop over the async iterator returned by kv.list().

Ensure you await kv.set() calls before listing to see all stored values.

Keys in Deno KV are arrays; use matching prefixes to filter listings.

Each entry from kv.list() has key and value properties to access.