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Usage

Returns if field is an existing field in the hash stored at key. 
await redis.hexists(key, field);

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Parameters

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key
string
required
The key of the hash
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field
string
required
The field name to check for existence

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Response

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exists
number
Returns 1 if the hash contains the field, 0 if the hash does not contain the field or the key does not exist.

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Examples

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Check if a field exists

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'
});

// Check if field exists
const hasName = await redis.hexists('user:1000', 'name');
console.log(hasName); // 1

const hasAge = await redis.hexists('user:1000', 'age');
console.log(hasAge); // 0

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Conditional field operations

// Only set a field if it doesn't exist
const exists = await redis.hexists('user:1000', 'defaultTheme');

if (!exists) {
  await redis.hset('user:1000', { defaultTheme: 'light' });
}

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Validate required fields

interface RequiredFields {
  name: boolean;
  email: boolean;
  phone: boolean;
}

const checkRequired = async (userId: string): Promise<RequiredFields> => {
  const [hasName, hasEmail, hasPhone] = await Promise.all([
    redis.hexists(`user:${userId}`, 'name'),
    redis.hexists(`user:${userId}`, 'email'),
    redis.hexists(`user:${userId}`, 'phone'),
  ]);

  return {
    name: hasName === 1,
    email: hasEmail === 1,
    phone: hasPhone === 1,
  };
};

const validation = await checkRequired('1000');
console.log(validation); // { name: true, email: true, phone: false }

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Check before deletion

// Check if field exists before attempting deletion
if (await redis.hexists('user:1000', 'tempToken')) {
  await redis.hdel('user:1000', 'tempToken');
  console.log('Temporary token removed');
}

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Feature flag checking

// Check if a user has a specific feature enabled
const hasFeature = await redis.hexists('user:1000:features', 'betaAccess');

if (hasFeature) {
  console.log('User has beta access');
}

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Non-existent key

// Check field on non-existent key
const exists = await redis.hexists('user:9999', 'name');
console.log(exists); // 0

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Notes

  • Returns 1 (not true) when the field exists
  • Returns 0 (not false) when the field doesn’t exist
  • Useful for conditional logic before setting or deleting fields
  • More efficient than getting the value when you only need to check existence

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See Also

  • HGET - Get a hash field value
  • HSET - Set hash field values
  • HDEL - Delete hash fields
  • HKEYS - Get all field names in a hash