## Write key-value pair with optional metadata

`client.kv.namespaces.values.update(stringnamespaceId, stringkeyName, ValueUpdateParamsparams, RequestOptionsoptions?): ValueUpdateResponse | null`

**put** `/accounts/{account_id}/storage/kv/namespaces/{namespace_id}/values/{key_name}`

Write a value identified by a key. Use URL-encoding to use special characters (for example, `:`, `!`, `%`) in the key name. Body should be the value to be stored. If JSON metadata to be associated with the key/value pair is needed, use `multipart/form-data` content type for your PUT request (see dropdown below in `REQUEST BODY SCHEMA`). Existing values, expirations, and metadata will be overwritten. If neither `expiration` nor `expiration_ttl` is specified, the key-value pair will never expire. If both are set, `expiration_ttl` is used and `expiration` is ignored.

### Parameters

- `namespaceId: string`

  Namespace identifier tag.

- `keyName: string`

  A key's name. The name may be at most 512 bytes. All printable, non-whitespace characters are valid. Use percent-encoding to define key names as part of a URL.

- `params: ValueUpdateParams`

  - `account_id: string`

    Path param: Identifier.

  - `value: string | Uploadable`

    Body param: A byte sequence to be stored, up to 25 MiB in length.

    - `string`

    - `Uploadable`

  - `expiration?: number`

    Query param: Expires the key at a certain time, measured in number of seconds since the UNIX epoch.

  - `expiration_ttl?: number`

    Query param: Expires the key after a number of seconds. Must be at least 60.

  - `metadata?: unknown`

    Body param: Associates arbitrary JSON data with a key/value pair.

### Returns

- `ValueUpdateResponse`

### Example

```node
import Cloudflare from 'cloudflare';

const client = new Cloudflare({
  apiToken: process.env['CLOUDFLARE_API_TOKEN'], // This is the default and can be omitted
});

const value = await client.kv.namespaces.values.update(
  '0f2ac74b498b48028cb68387c421e279',
  'My-Key',
  { account_id: '023e105f4ecef8ad9ca31a8372d0c353', value: 'Some Value' },
);

console.log(value);
```

#### Response

```json
{
  "errors": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "messages": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "success": true,
  "result": {}
}
```