---
title: KV
description: "A key-value store bound to env.NAME."
---

## Configuration

```jsonc
"kv_namespaces": ["SESSIONS"]
```

Bare names are auto-provisioned on deploy; see [Storage resources](/docs/storage).

## Usage

```js
env.SESSIONS.put("k", "v");
env.SESSIONS.put("session:abc", token, { expirationTtl: 3600 });
env.SESSIONS.get("k");               // -> "v" or null
env.SESSIONS.delete("k");
env.SESSIONS.list("session:");       // -> string[] of keys
```

From compatibility date `2026-10-25` KV calls return Promises, as on Workers; before it they are synchronous. `await` works at both.

## Methods

| Method | Signature | Returns |
| --- | --- | --- |
| `put` | `(key, value, { expirationTtl?, expiration? })` | `void`. The value is converted to a string. |
| `get` | `(key)` | `string \| null` |
| `delete` | `(key)` | `void` |
| `list` | `(prefix?)` | `string[]` of keys, sorted. Up to 1000 on the platform. |

`expirationTtl` is seconds from now, at least 60. `expiration` is an absolute time in Unix seconds. An expired key reads as `null` and is left out of `list`.

## Related

- [Storage resources and auto-provisioning](/docs/storage)
- [Manage and export KV data](/docs/storage/manage-kv-data): list, read, edit and export keys from the CLI