> ## 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.

# SUNION

> Get the union of multiple sets

Returns the members of the set resulting from the union of all the given sets. Keys that do not exist are considered to be empty sets.

## Usage

```typescript theme={null}
await redis.sunion(key, ...keys);
```

## Parameters

<ParamField body="key" type="string" required>
  The first set key
</ParamField>

<ParamField body="keys" type="string[]">
  Additional set keys to union with
</ParamField>

## Response

<ResponseField name="result" type="TData[]">
  An array containing the members of the resulting set (union of all sets)
</ResponseField>

## Examples

### Union of two sets

```typescript theme={null}
await redis.sadd("set1", "a", "b", "c");
await redis.sadd("set2", "c", "d", "e");

const result = await redis.sunion("set1", "set2");
console.log(result); // ["a", "b", "c", "d", "e"]
```

### Union of multiple sets

```typescript theme={null}
await redis.sadd("skills:alice", "javascript", "python");
await redis.sadd("skills:bob", "python", "go");
await redis.sadd("skills:charlie", "java", "javascript");

const allSkills = await redis.sunion(
  "skills:alice",
  "skills:bob",
  "skills:charlie"
);
console.log(allSkills); // ["javascript", "python", "go", "java"]
```

### Combine tag sets

```typescript theme={null}
await redis.sadd("tags:frontend", "react", "vue", "angular");
await redis.sadd("tags:backend", "node", "django", "rails");

const allTags = await redis.sunion("tags:frontend", "tags:backend");
console.log(allTags);
// ["react", "vue", "angular", "node", "django", "rails"]
```

### Union with non-existing set

```typescript theme={null}
await redis.sadd("set1", "a", "b", "c");

const result = await redis.sunion("set1", "nonexistent");
console.log(result); // ["a", "b", "c"]
```