> ## Documentation Index
> Fetch the complete documentation index at: https://docs.larksh.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Utilities

> Helper functions and constants exported by the Lark SDK

The `@lark-sh/client` package exports several utility functions and constants for working with paths, IDs, and server values.

```typescript theme={null}
import {
  generatePushId,
  ServerValue,
  normalizePath,
  joinPath,
  getParentPath,
  getKey,
  isVolatilePath,
} from '@lark-sh/client';
```

## generatePushId

```typescript theme={null}
generatePushId(): string
```

Generates a unique, chronologically-sortable 20-character ID. The format is identical to the keys produced by [`DatabaseReference.push()`](/lark-sdk/api/database-reference#push).

IDs are ordered by time, so items created earlier sort before items created later when using `orderByKey()`.

```typescript theme={null}
const id = generatePushId();
// e.g. "-NxK3jR2fHa0YkLm9pQr"

await db.ref(`posts/${id}`).set({
  title: 'My Post',
  createdAt: ServerValue.TIMESTAMP,
});
```

<Tip>
  Use `generatePushId()` when you need a key before writing, such as when referencing the key in multiple locations within a single `update()` call.
</Tip>

## ServerValue.TIMESTAMP

```typescript theme={null}
ServerValue.TIMESTAMP: object
```

A placeholder value that the server replaces with its current timestamp (milliseconds since the Unix epoch) at the time the write is committed. Use this instead of `Date.now()` to ensure consistency across clients with different clock offsets.

```typescript theme={null}
await db.ref('users/alice').update({
  lastLogin: ServerValue.TIMESTAMP,
});
```

<Note>
  `ServerValue.TIMESTAMP` is a sentinel object, not an actual number. It is resolved server-side when the write is processed.
</Note>

## normalizePath

```typescript theme={null}
normalizePath(path: string): string
```

Normalizes a database path by removing double slashes, trailing slashes, and leading slashes.

| Parameter | Type     | Description            |
| --------- | -------- | ---------------------- |
| `path`    | `string` | The path to normalize. |

```typescript theme={null}
normalizePath('//users//alice/');
// "users/alice"

normalizePath('/');
// ""
```

## joinPath

```typescript theme={null}
joinPath(...segments: string[]): string
```

Joins one or more path segments with `/`, producing a normalized path.

| Parameter     | Type       | Description            |
| ------------- | ---------- | ---------------------- |
| `...segments` | `string[]` | Path segments to join. |

```typescript theme={null}
joinPath('users', 'alice', 'profile');
// "users/alice/profile"

joinPath('rooms', 'room1', 'members');
// "rooms/room1/members"
```

## getParentPath

```typescript theme={null}
getParentPath(path: string): string
```

Returns the parent path of the given path. Returns an empty string for top-level paths.

| Parameter | Type     | Description                    |
| --------- | -------- | ------------------------------ |
| `path`    | `string` | The path to get the parent of. |

```typescript theme={null}
getParentPath('users/alice/profile');
// "users/alice"

getParentPath('users');
// ""
```

## getKey

```typescript theme={null}
getKey(path: string): string
```

Returns the last segment of a path (the key).

| Parameter | Type     | Description                       |
| --------- | -------- | --------------------------------- |
| `path`    | `string` | The path to extract the key from. |

```typescript theme={null}
getKey('users/alice/profile');
// "profile"

getKey('users');
// "users"
```

## isVolatilePath

```typescript theme={null}
isVolatilePath(path: string, patterns: string[]): boolean
```

Checks whether a given path matches any of the provided volatile path patterns. Volatile paths are used for high-frequency, low-latency data streams such as cursor positions or live indicators.

| Parameter  | Type       | Description                                                                                             |
| ---------- | ---------- | ------------------------------------------------------------------------------------------------------- |
| `path`     | `string`   | The path to check.                                                                                      |
| `patterns` | `string[]` | An array of volatile path patterns to match against. Patterns support `*` as a single-segment wildcard. |

```typescript theme={null}
const patterns = ['cursors/*', 'typing/*'];

isVolatilePath('cursors/alice', patterns);
// true

isVolatilePath('users/alice', patterns);
// false
```