Description Set key to hold the string value. If key already holds a value, it is overwritten, regardless of its type. Any previous time to live associated with the key is discarded on successful SET operation.
Syntax redis . set < TData >( key : string , value : TData , opts ?: SetCommandOptions ): Promise < TData | "OK" | null >
Parameters The value to store. Can be a string, number, object, or any serializable data
Optional configuration for the SET command Set the specified expire time, in seconds (a positive integer)
Set the specified expire time, in milliseconds (a positive integer)
Set the specified Unix time at which the key will expire, in seconds (a positive integer)
Set the specified Unix time at which the key will expire, in milliseconds (a positive integer)
Only set the key if it does not already exist
Only set the key if it already exists
Retain the time to live associated with the key
Return the old string stored at key, or null if key did not exist
Type Parameters The type of the value being stored
Returns
Returns "OK" if SET was executed correctly
Returns null if the SET operation was not performed (due to nx or xx conditions)
Returns the old value if the get option was specified
Examples Basic Usage import { Redis } from '@upstash/redis' ; const redis = new Redis ({ url: 'https://your-redis-url.upstash.io' , token: 'your-token' }); // Simple string set await redis . set ( 'greeting' , 'Hello, World!' ); // Returns: "OK" // Set a number await redis . set ( 'counter' , 42 ); // Returns: "OK"
Set with Expiration // Expire in 60 seconds await redis . set ( 'session:abc' , 'user-data' , { ex: 60 }); // Expire in 5000 milliseconds await redis . set ( 'temp:key' , 'value' , { px: 5000 }); // Expire at specific Unix timestamp (seconds) const expirationTime = Math . floor ( Date . now () / 1000 ) + 3600 ; // 1 hour from now await redis . set ( 'token' , 'secret-token' , { exat: expirationTime }); // Expire at specific Unix timestamp (milliseconds) const expirationTimeMs = Date . now () + 3600000 ; // 1 hour from now await redis . set ( 'token' , 'secret-token' , { pxat: expirationTimeMs });
Conditional Set // Only set if key doesn't exist (SET NX) const result1 = await redis . set ( 'key' , 'value' , { nx: true }); console . log ( result1 ); // "OK" if key didn't exist, null otherwise // Only set if key exists (SET XX) const result2 = await redis . set ( 'key' , 'new-value' , { xx: true }); console . log ( result2 ); // "OK" if key existed, null otherwise
Set and Get Old Value // Set initial value await redis . set ( 'score' , 100 ); // Set new value and get the old one const oldValue = await redis . set ( 'score' , 200 , { get: true }); console . log ( oldValue ); // 100
Working with Objects interface User { id : number ; name : string ; email : string ; } const user : User = { id: 1 , name: 'Alice' , email: '[email protected] ' }; // Store object with 1 hour expiration await redis . set ( 'user:1' , user , { ex: 3600 });
Keep TTL // Set a key with expiration await redis . set ( 'key' , 'value1' , { ex: 300 }); // 5 minutes // Update the value but keep the remaining TTL await redis . set ( 'key' , 'value2' , { keepTtl: true }); // The key still has the same remaining TTL from the first SET
Notes
The ex, px, exat, pxat, and keepTtl options are mutually exclusive
The nx and xx options are mutually exclusive
When using the get option, the command returns the old value instead of "OK"
get - Get the value of a keymset - Set multiple keys to multiple values
Redis Documentation For more information, see the Redis SET documentation .