---
source_url: https://www.pubnub.com/docs/serverless/functions/functions-apis/kvstore-module
title: KV Store Module
updated_at: 2026-06-04T11:13:42.902Z
---

> Documentation Index
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> For the full list of all documentation pages, see: https://www.pubnub.com/docs/llms-full.txt


# KV Store Module

:::tip KV Store API
In Functions v2, you can use the KV store module or call the PubNub API to store your Functions data. For API details, see the [REST API](https://www.pubnub.com/docs/serverless/functions/functions-rest-api/functions-api) docs.
:::

The `kvstore` module is a persistent key value store that acts as a database for your Functions. This database is globally distributed and eventually consistent.

:::note Maximum recursion limit
1. The maximum recursion limit you can do is `3` - hops from one Function to another, using `publish` or `fire`, you can execute a maximum of three Functions.
2. The combined maximum number within a single Function execution of `KV store` operations, `XHRs`, `publish` and `fire` is `3`.
:::

All KV store methods return a promise object.

The `kvstore` module is made available via the following `require()` statement:

```javascript
const db = require("kvstore");
```

## Scope

KV store data is scoped at a subscribe key level. This means that data stored within the KV store is globally replicated across all PoPs, and available for all Functions under the same keyset to access.

:::note Maximum keys and value length
The maximum length of the `key` is `1000` characters and the maximum length of the `value` is `32000` characters.
:::

## Data time to live (TTL)

When data is stored in the KV store, you can set the Time to Live (TTL). By default the TTL is 1 day.

## kvstore.set()

```javascript
const db = require("kvstore");
db.set("key", {value: true});
```

Takes a string key as the first parameter, a Javascript object as the second parameter. Data is stored persistently and is available whenever a block is triggered.

### kvstore.set() with TTL

```javascript
const db = require("kvstore");
db.set("key", {value: true}, 2880);
```

Takes a string key as the first parameter, a Javascript object as the second parameter, and an integer TTL as the third parameter, which is set in minutes.

Data is stored persistently and is available whenever a block is triggered. TTL causes expiration of the stored object. In the example, the TTL is set to `2` days. The minimum value of TTL is `1` minute, and the maximum value is `1` year. Specifying a value less than 1 minute sets the TTL to `1` minute, and specifying a value more than `1` year sets the TTL to `1` year. If not specified, the value defaults to `1` day.

## kvstore.get()

```javascript
const db = require("kvstore");
db.get("key").then((value) => {
    console.log("value", value);
});
```

Takes a string as the only parameter and retrieves the stored value from the database.

## kvstore.setItem()

```javascript
const db = require("kvstore");
db.setItem("key", "value");
```

Takes a string key as the first parameter and a string value as the second parameter. Same as `db.set()` but optimized for string values.

### kvstore.setItem() with TTL

```javascript
const db = require("kvstore");
db.setItem("key", "value", 2880);
```

Takes a string key as the first parameter, a string value as the second parameter, and an integer TTL as the third parameter, which is set in minutes.

TTL causes expiration of the stored object. In the example, the TTL is set to `2` days. The minimum value of TTL is `1` minute, and the maximum value is `1` year. Specifying a value less than 1 minute sets the TTL to `1` minute, and specifying a value more than `1` year sets the TTL to `1` year. If not specified, the value defaults to `1` day.

## kvstore.getItem()

```javascript
const db = require("kvstore");
db.getItem("key").then((value) => {
    console.log("value", value);
});
```

Takes a string as the only parameter and retrieves the stored value from the database. Same as `db.get()` but optimized for string values.

## kvstore.removeItem()

```javascript
const db = require("kvstore");
db.removeItem("key");
```

Takes a string as the only parameter and removes the stored value from the database.

## kvstore.getKeys()

```javascript
const db = require("kvstore");
db.getKeys().then((keys) => {
        for(var i=0; i<keys.length;i++){
            console.log(keys[i])
        }

    });
```

Lists all keys from `kvstore`.

The method returns a maximum of `100` keys. The method accepts a string argument for paginating results. The `pagination_key` should be the last key returned from a previous response (or undefined for the first response). Using a static index like `result[99]` would break code when the limit is changed.

## Counters

Counters are an efficient way to increment a stored number in an atomic fashion. Counters stored in the key/value storage are not subjected to TTL.

### kvstore.getCounter()

```javascript
const db = require("kvstore");
db.getCounter("key").then((counter) => {
    console.log("counter", counter);
});
```

Takes a string as the only parameter and retrieves the stored counter value from the database. Returns 0L if no counter under `key` has yet been incremented.

### kvstore.incrCounter()

```javascript
const db = require("kvstore");
db.incrCounter("key", number);
```

Takes a string as the first parameter and a number as the second parameter. Increments counter stored under `key` by number. Creates a new counter initialized to zero if none yet exist under `key`. If the number is not set, the value defaults to `1`.

### kvstore.getCounterKeys()

```javascript
const db = require("kvstore");
db.getCounterKeys().then((counterKeys) => {
        for(var i=0; i<counterKeys.length;i++){
            console.log(counterKeys[i])
        }
    });
```

Lists all keys from the `KV Store Counter`.

The method returns a maximum of `100` keys. The method accepts a string argument for paginating results. The `pagination_key` should be the last key returned from a previous response (or undefined for the first response). Using a static index like `result[99]` would break code when the limit is changed.

:::note Functions support
Functions provides a rich set of tools, and this documentation does not cover all of the potential situations you may encounter. If you need help with a situation not covered by the documentation, please contact [PubNub Support](https://www.pubnub.com/docs/mailto:support@pubnub.com)
:::

## Terms in this document

* **PubNub** - PubNub is a real-time messaging platform that provides APIs and SDKs for building scalable applications. It handles the complex infrastructure of real-time communication, including: Message delivery and persistence, Presence detection, Access control, Push notifications, File sharing, Serverless processing with Functions and Events & Actions, Analytics and monitoring with BizOps Workspace, AI-powered insights with Illuminate.
* **Subscribe Key** - A unique identifier that allows your application to receive messages from PubNub channels. It's part of your app's credentials and should be kept secure.