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

# HKEYS

> Get all field names in a hash

## Usage

Returns all field names in the hash stored at `key`.

```typescript theme={null}
await redis.hkeys(key);
```

## Parameters

<ParamField path="key" type="string" required>
  The key of the hash
</ParamField>

## Response

<ResponseField name="fields" type="string[]">
  An array of field names in the hash. Returns an empty array if the key does not exist.
</ResponseField>

## Examples

### Get all field names

```typescript theme={null}
import { Redis } from '@upstash/redis';

const redis = new Redis({
  url: process.env.UPSTASH_REDIS_REST_URL!,
  token: process.env.UPSTASH_REDIS_REST_TOKEN!,
});

// Set hash fields
await redis.hset('user:1000', {
  name: 'Alice',
  email: 'alice@example.com',
  age: 30,
  city: 'New York'
});

// Get all field names
const fields = await redis.hkeys('user:1000');
console.log(fields); // ['name', 'email', 'age', 'city']
```

### Check available fields

```typescript theme={null}
const fields = await redis.hkeys('user:1000');

if (fields.includes('email')) {
  console.log('Email field exists');
}

if (fields.includes('phone')) {
  console.log('Phone field exists');
} else {
  console.log('Phone field is missing');
}
```

### Iterate over fields

```typescript theme={null}
const fields = await redis.hkeys('user:1000');

for (const field of fields) {
  const value = await redis.hget('user:1000', field);
  console.log(`${field}: ${value}`);
}
```

### Get field count

```typescript theme={null}
const fields = await redis.hkeys('user:1000');
console.log(`Total fields: ${fields.length}`);
```

### Validate schema

```typescript theme={null}
const requiredFields = ['name', 'email', 'id'];
const actualFields = await redis.hkeys('user:1000');

const missingFields = requiredFields.filter(field => !actualFields.includes(field));

if (missingFields.length > 0) {
  console.log(`Missing required fields: ${missingFields.join(', ')}`);
}
```

### Non-existent key

```typescript theme={null}
const fields = await redis.hkeys('user:9999');
console.log(fields); // []
```

### Filter fields by pattern

```typescript theme={null}
// Get all fields
const allFields = await redis.hkeys('user:1000:settings');

// Filter fields that start with 'notification'
const notificationFields = allFields.filter(field => field.startsWith('notification'));
console.log(notificationFields);
// ['notificationEmail', 'notificationPush', 'notificationSMS']
```

### Compare field sets

```typescript theme={null}
const user1Fields = await redis.hkeys('user:1000');
const user2Fields = await redis.hkeys('user:2000');

// Find fields unique to user1
const uniqueToUser1 = user1Fields.filter(field => !user2Fields.includes(field));
console.log('Unique to user1:', uniqueToUser1);
```

### Export field names for documentation

```typescript theme={null}
const fields = await redis.hkeys('config:app');

console.log('Available configuration fields:');
fields.forEach(field => {
  console.log(`- ${field}`);
});
```

## Notes

* The order of fields in the returned array is not guaranteed
* Returns an empty array for non-existent keys
* Use `HGETALL` if you need both field names and values
* For very large hashes, consider using `HSCAN` to iterate incrementally

## See Also

* [HVALS](/api/commands/hvals) - Get all values in a hash
* [HGETALL](/api/commands/hgetall) - Get all fields and values in a hash
* [HEXISTS](/api/commands/hexists) - Check if a hash field exists