Key-value store schema specification

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The key‑value store schema organizes keys into logical groups called collections, which can be used to filter and categorize data both in the API and the visual user interface. This organization helps users navigate and find specific data more efficiently, while schema‑defined rules (such as content types and JSON schema) ensure that stored values remain consistent and valid.

Schema components

A key-value store schema has one component:

• collections (required) - Named groups of keys, each defined by a shared key prefix or a single key. A collection can also validate the content type of its records and, for JSON, validate them against a JSON Schema.

.actor/key_value_store_schema.json

{
    "actorKeyValueStoreSchemaVersion": 1,
    "title": "Key-value store schema",
    "collections": {
        "documents": {
            "title": "Documents",
            "keyPrefix": "document-"
        }
    }
}

File structure

Place the key-value store schema in the .actor folder in your Actor's root directory. You can organize it in two ways:

Inline in actor.json

.actor/actor.json

{
    "actorSpecification": 1,
    "name": "this-is-book-library-scraper",
    "title": "Book Library scraper",
    "version": "1.0.0",
    "storages": {
        "keyValueStore": {
            "actorKeyValueStoreSchemaVersion": 1,
            "title": "Key-Value Store Schema",
            "collections": { /* Define your collections here */ }
        }
    }
}

Separate file

.actor/actor.json

{
    "actorSpecification": 1,
    "name": "this-is-book-library-scraper",
    "title": "Book Library scraper",
    "version": "1.0.0",
    "storages": {
        "keyValueStore": "./key_value_store_schema.json"
    }
}

.actor/key_value_store_schema.json

{
    "actorKeyValueStoreSchemaVersion": 1,
    "title": "Key-Value Store Schema",
    "collections": { /* Define your collections here */ }
}

Use a separate file when your schema is complex or you want to keep actor.json concise.

Collections

Collections group related keys so they are easier to find and filter in Apify Console and through the API. Define each collection by a shared key prefix or a single key, and optionally validate the records it holds.

Define collection membership

Each collection defines its member keys using one of the following properties:

• keyPrefix - Includes all keys that start with the specified prefix (for example, all keys starting with document-).
• key - Includes a single specific key.

Use either key or keyPrefix for each collection, but not both.

Validate record content

When you define a collection with specific contentTypes, the Apify platform validates any data stored in that collection against those specifications. For example, if you specify that a collection should only contain JSON data with content type application/json, attempts to store data with other content types in that collection are rejected.

The validation happens automatically when you call Actor.setValue() or use the Put record API endpoint.

If you define a jsonSchema for a collection with content type application/json, the platform also validates that the JSON data conforms to the specified schema. This helps ensure data consistency and prevents storing malformed data.

Collection example

Consider an Actor that calls Actor.setValue() to save records into the key-value store:

main.js

import { Actor } from 'apify';
// Initialize the JavaScript SDK
await Actor.init();

/**
 * Actor code
 */
await Actor.setValue('document-1', 'my text data', { contentType: 'text/plain' });

// ...

await Actor.setValue(`image-${imageID}`, imageBuffer, { contentType: 'image/jpeg' });

// Exit successfully
await Actor.exit();

To organize those records, define collections in the .actor/actor.json configuration:

.actor/actor.json

{
    "actorSpecification": 1,
    "name": "Actor Name",
    "title": "Actor Title",
    "version": "1.0.0",
    "storages": {
        "keyValueStore": {
            "actorKeyValueStoreSchemaVersion": 1,
            "title": "Key-Value Store Schema",
            "collections": {
                "documents": {
                    "title": "Documents",
                    "description": "Text documents stored by the Actor.",
                    "keyPrefix": "document-"
                },
                "images": {
                    "title": "Images",
                    "description": "Images stored by the Actor.",
                    "keyPrefix": "image-",
                    "contentTypes": ["image/jpeg"]
                }
            }
        }
    }
}

This defines two collections for the default key-value store: documents for text keys prefixed document-, and images for JPEG keys prefixed image-.

Once the schema is defined, tabs for each collection appear in the Storage tab of the Actor's run:

The tabs also appear in the storage detail view:

List keys by collection via the API

With the schema defined, use the API to list keys from a specific collection with the collection query parameter on the Get list of keys endpoint:

Get list of keys from a collection

GET https://api.apify.com/v2/key-value-stores/{storeId}/keys?collection=documents

Example response:

{
  "data": {
    "items": [
      {
        "key": "document-1",
        "size": 254
      },
      {
        "key": "document-2",
        "size": 368
      }
    ],
    "count": 2,
    "limit": 1000,
    "exclusiveStartKey": null,
    "isTruncated": false
  }
}

You can also filter by key prefix using the prefix parameter:

Get list of keys with prefix

GET https://api.apify.com/v2/key-value-stores/{storeId}/keys?prefix=document-

Reference

The key-value store schema defines the collections of keys and their properties. It allows you to organize and validate data stored by the Actor, making it easier to manage and retrieve specific records.

KeyValueStoreSchema object

Property	Type	Required	Description
actorKeyValueStoreSchemaVersion	integer	true	Specifies the version of key-value store schema structure document. Currently only version 1 is available.
title	string	true	Title of the schema
description	string	false	Description of the schema
collections	Object	true	An object where each key is a collection ID and its value is a collection definition object (see below).

Collection object

Property	Type	Required	Description
title	string	true	The collection’s title, shown in the run's storage tab and in the storage detail view, where it appears as a tab for filtering records.
description	string	false	A description of the collection that appears in UI tooltips.
key	string	conditional*	Defines a single specific key that will be part of this collection.
keyPrefix	string	conditional*	Defines a prefix for keys that should be included in this collection.
contentTypes	string array	false	Allowed content types for records in this collection. Used for validation when storing data.
jsonSchema	object	false	For collections with content type application/json, you can define a JSON schema to validate structure. Uses JSON Schema Draft 07 format.

* Either key or keyPrefix must be specified for each collection, but not both.