# Update a Collection

PUT https://api.prolific.com/api/v1/data-collection/collections/{collection_id}
Content-Type: application/json

Update an existing AI Task Builder Collection. This is a full replacement — all fields must be provided.

To preserve existing entities (collection items, page items) when updating, include their `id` fields in the request. Entities without IDs will be created as new, and existing entities not included in the request will be deleted.

Reference: https://beta-docs.prolific.com/api-reference/ai-task-builder/update-collection

## OpenAPI Specification

```yaml
openapi: 3.1.1
info:
  title: Update a Collection
  version: endpoint_aiTaskBuilder.UpdateCollection
paths:
  /api/v1/data-collection/collections/{collection_id}:
    put:
      operationId: update-collection
      summary: Update a Collection
      description: >-
        Update an existing AI Task Builder Collection. This is a full
        replacement — all fields must be provided.


        To preserve existing entities (collection items, page items) when
        updating, include their `id` fields in the request. Entities without IDs
        will be created as new, and existing entities not included in the
        request will be deleted.
      tags:
        - - subpackage_aiTaskBuilder
      parameters:
        - name: collection_id
          in: path
          required: true
          schema:
            type: string
        - name: Authorization
          in: header
          description: Header authentication of the form `undefined <token>`
          required: true
          schema:
            type: string
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Collection'
        '400':
          description: Error
          content: {}
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CollectionUpdateRequest'
components:
  schemas:
    TaskDetails:
      type: object
      properties:
        task_name:
          type: string
          description: The title displayed to participants
        task_introduction:
          type: string
          description: HTML formatted introduction shown at the start of the task
        task_steps:
          type: string
          description: HTML formatted step-by-step instructions
      required:
        - task_name
        - task_introduction
        - task_steps
    CollectionInstructionInputType:
      type: string
      enum:
        - value: multiple_choice
        - value: free_text
        - value: multiple_choice_with_free_text
        - value: file_upload
    CollectionInstructionInputOptionsItemsValue:
      oneOf:
        - type: string
        - type: number
          format: double
        - type: boolean
    CollectionInstructionInputOptionsItems:
      type: object
      properties:
        label:
          type: string
        value:
          $ref: '#/components/schemas/CollectionInstructionInputOptionsItemsValue'
        heading:
          type: string
          description: Required for multiple_choice_with_free_text
      required:
        - label
        - value
    CollectionInstructionInput:
      type: object
      properties:
        id:
          type: string
          format: uuid
          description: Include to preserve an existing instruction when updating
        type:
          $ref: '#/components/schemas/CollectionInstructionInputType'
        description:
          type: string
          description: The question or prompt displayed to participants
        order:
          type: integer
          description: Position of this instruction relative to others
        helper_text:
          type: string
          description: Additional guidance text displayed below the question
        placeholder_text_input:
          type: string
          description: Placeholder text displayed in the input field
        answer_limit:
          type: integer
          description: >-
            Number of options that can be selected. Use 1 for single-select, -1
            for unlimited.
        disable_dropdown:
          type: boolean
          default: false
          description: >-
            When true, always renders checkbox/radio elements instead of a
            dropdown select.
        options:
          type: array
          items:
            $ref: '#/components/schemas/CollectionInstructionInputOptionsItems'
      required:
        - type
        - description
        - order
    ContentBlockInputType:
      type: string
      enum:
        - value: image
        - value: rich_text
    ContentBlockInput:
      type: object
      properties:
        id:
          type: string
          format: uuid
          description: Include to preserve an existing content block when updating
        type:
          $ref: '#/components/schemas/ContentBlockInputType'
        url:
          type: string
          format: uri
          description: HTTPS URL for image content blocks
        alt_text:
          type: string
          description: Alt text for image content blocks (required for accessibility)
        caption:
          type: string
          description: Optional caption for image content blocks
        content:
          type: string
          description: Markdown content for rich_text content blocks
      required:
        - type
    PageItemInput:
      oneOf:
        - $ref: '#/components/schemas/CollectionInstructionInput'
        - $ref: '#/components/schemas/ContentBlockInput'
    CollectionItemInput:
      type: object
      properties:
        id:
          type: string
          format: uuid
          description: Include to preserve an existing page when updating
        page_items:
          type: array
          items:
            $ref: '#/components/schemas/PageItemInput'
          description: Instructions and content blocks on this page
      required:
        - page_items
    CollectionUpdateRequest:
      type: object
      properties:
        name:
          type: string
          description: The name of the collection
        task_details:
          $ref: '#/components/schemas/TaskDetails'
        collection_items:
          type: array
          items:
            $ref: '#/components/schemas/CollectionItemInput'
          description: >-
            Pages within the collection. Include `id` to preserve existing
            items.
      required:
        - name
        - task_details
        - collection_items
    CollectionSchemaVersion:
      type: string
      enum:
        - value: '1'
    CollectionItemSchemaVersion:
      type: string
      enum:
        - value: '1'
    CollectionMultipleChoiceInstructionType:
      type: string
      enum:
        - value: multiple_choice
    CollectionMultipleChoiceInstructionOptionsItemsValue:
      oneOf:
        - type: string
        - type: number
          format: double
        - type: boolean
    CollectionMultipleChoiceInstructionOptionsItems:
      type: object
      properties:
        label:
          type: string
        value:
          $ref: >-
            #/components/schemas/CollectionMultipleChoiceInstructionOptionsItemsValue
      required:
        - label
        - value
    CollectionMultipleChoiceInstruction:
      type: object
      properties:
        id:
          type: string
          format: uuid
        created_at:
          type: string
          format: date-time
        type:
          $ref: '#/components/schemas/CollectionMultipleChoiceInstructionType'
        collection_id:
          type: string
          format: uuid
        created_by:
          type: string
        description:
          type: string
        order:
          type: integer
        helper_text:
          type: string
          description: Additional guidance text displayed below the question
        placeholder_text_input:
          type: string
          description: Placeholder text displayed in the input field
        answer_limit:
          type: integer
        disable_dropdown:
          type: boolean
          default: false
        options:
          type: array
          items:
            $ref: >-
              #/components/schemas/CollectionMultipleChoiceInstructionOptionsItems
      required:
        - id
        - created_at
        - type
        - collection_id
        - created_by
        - description
        - order
        - answer_limit
        - options
    CollectionFreeTextInstructionType:
      type: string
      enum:
        - value: free_text
    CollectionFreeTextInstruction:
      type: object
      properties:
        id:
          type: string
          format: uuid
        created_at:
          type: string
          format: date-time
        type:
          $ref: '#/components/schemas/CollectionFreeTextInstructionType'
        collection_id:
          type: string
          format: uuid
        created_by:
          type: string
        description:
          type: string
        order:
          type: integer
        helper_text:
          type: string
          description: Additional guidance text displayed below the question
        placeholder_text_input:
          type: string
          description: Placeholder text displayed in the input field
      required:
        - id
        - created_at
        - type
        - collection_id
        - created_by
        - description
        - order
    CollectionMultipleChoiceWithFreeTextInstructionType:
      type: string
      enum:
        - value: multiple_choice_with_free_text
    CollectionMultipleChoiceWithFreeTextInstructionOptionsItemsValue:
      oneOf:
        - type: string
        - type: number
          format: double
        - type: boolean
    CollectionMultipleChoiceWithFreeTextInstructionOptionsItems:
      type: object
      properties:
        label:
          type: string
        value:
          $ref: >-
            #/components/schemas/CollectionMultipleChoiceWithFreeTextInstructionOptionsItemsValue
        heading:
          type: string
      required:
        - label
        - value
        - heading
    CollectionMultipleChoiceWithFreeTextInstruction:
      type: object
      properties:
        id:
          type: string
          format: uuid
        created_at:
          type: string
          format: date-time
        type:
          $ref: >-
            #/components/schemas/CollectionMultipleChoiceWithFreeTextInstructionType
        collection_id:
          type: string
          format: uuid
        created_by:
          type: string
        description:
          type: string
        order:
          type: integer
        helper_text:
          type: string
          description: Additional guidance text displayed below the question
        placeholder_text_input:
          type: string
          description: Placeholder text displayed in the input field
        answer_limit:
          type: integer
        disable_dropdown:
          type: boolean
          default: false
        options:
          type: array
          items:
            $ref: >-
              #/components/schemas/CollectionMultipleChoiceWithFreeTextInstructionOptionsItems
      required:
        - id
        - created_at
        - type
        - collection_id
        - created_by
        - description
        - order
        - answer_limit
        - options
    CollectionFileUploadInstructionType:
      type: string
      enum:
        - value: file_upload
    CollectionFileUploadInstruction:
      type: object
      properties:
        id:
          type: string
          format: uuid
        created_at:
          type: string
          format: date-time
        type:
          $ref: '#/components/schemas/CollectionFileUploadInstructionType'
        collection_id:
          type: string
          format: uuid
        created_by:
          type: string
        description:
          type: string
        order:
          type: integer
        helper_text:
          type: string
          description: Additional guidance text displayed below the question
        placeholder_text_input:
          type: string
          description: Placeholder text displayed in the input field
      required:
        - id
        - created_at
        - type
        - collection_id
        - created_by
        - description
        - order
    CollectionInstruction:
      oneOf:
        - $ref: '#/components/schemas/CollectionMultipleChoiceInstruction'
        - $ref: '#/components/schemas/CollectionFreeTextInstruction'
        - $ref: '#/components/schemas/CollectionMultipleChoiceWithFreeTextInstruction'
        - $ref: '#/components/schemas/CollectionFileUploadInstruction'
    ImageContentBlockType:
      type: string
      enum:
        - value: image
    ImageContentBlockParentType:
      type: string
      enum:
        - value: collection
        - value: batch
    ImageContentBlockSchemaVersion:
      type: string
      enum:
        - value: '1'
    ImageContentBlock:
      type: object
      properties:
        id:
          type: string
          format: uuid
        created_at:
          type: string
          format: date-time
        type:
          $ref: '#/components/schemas/ImageContentBlockType'
        parent_id:
          type: string
          format: uuid
          description: ID of the parent collection item (page)
        parent_type:
          $ref: '#/components/schemas/ImageContentBlockParentType'
        created_by:
          type: string
        schema_version:
          $ref: '#/components/schemas/ImageContentBlockSchemaVersion'
        url:
          type: string
          format: uri
          description: HTTPS URL of the image
        alt_text:
          type: string
          description: Alt text for accessibility
        caption:
          type: string
          description: Optional caption displayed below the image
      required:
        - id
        - created_at
        - type
        - parent_id
        - parent_type
        - created_by
        - schema_version
        - url
        - alt_text
    RichTextContentBlockType:
      type: string
      enum:
        - value: rich_text
    RichTextContentBlockParentType:
      type: string
      enum:
        - value: collection
        - value: batch
    RichTextContentBlockSchemaVersion:
      type: string
      enum:
        - value: '1'
    RichTextContentBlock:
      type: object
      properties:
        id:
          type: string
          format: uuid
        created_at:
          type: string
          format: date-time
        type:
          $ref: '#/components/schemas/RichTextContentBlockType'
        parent_id:
          type: string
          format: uuid
          description: ID of the parent collection item (page)
        parent_type:
          $ref: '#/components/schemas/RichTextContentBlockParentType'
        created_by:
          type: string
        schema_version:
          $ref: '#/components/schemas/RichTextContentBlockSchemaVersion'
        content:
          type: string
          description: Markdown formatted content
      required:
        - id
        - created_at
        - type
        - parent_id
        - parent_type
        - created_by
        - schema_version
        - content
    ContentBlock:
      oneOf:
        - $ref: '#/components/schemas/ImageContentBlock'
        - $ref: '#/components/schemas/RichTextContentBlock'
    PageItem:
      oneOf:
        - $ref: '#/components/schemas/CollectionInstruction'
        - $ref: '#/components/schemas/ContentBlock'
    CollectionItem:
      type: object
      properties:
        id:
          type: string
          format: uuid
        created_at:
          type: string
          format: date-time
        created_by:
          type: string
        schema_version:
          $ref: '#/components/schemas/CollectionItemSchemaVersion'
        page_items:
          type: array
          items:
            $ref: '#/components/schemas/PageItem'
          description: Instructions and content blocks on this page
      required:
        - id
        - created_at
        - created_by
        - schema_version
        - page_items
    Collection:
      type: object
      properties:
        id:
          type: string
          format: uuid
        schema_version:
          $ref: '#/components/schemas/CollectionSchemaVersion'
        created_at:
          type: string
          format: date-time
          description: ISO-8601 formatted creation timestamp in UTC
        created_by:
          type: string
          description: User ID of the Prolific user that created the collection
        workspace_id:
          type: string
          description: The ID of the Prolific workspace
        name:
          type: string
          description: The name of the collection
        task_details:
          $ref: '#/components/schemas/TaskDetails'
        collection_items:
          type: array
          items:
            $ref: '#/components/schemas/CollectionItem'
          description: Pages within the collection. Each collection item represents a page.
        last_modified_at:
          type: string
          format: date-time
          description: ISO-8601 formatted last modification timestamp in UTC
        last_modified_by:
          type: string
          description: User ID of the Prolific user that last modified the collection
      required:
        - id
        - schema_version
        - created_at
        - created_by
        - workspace_id
        - name
        - task_details
        - collection_items

```

## SDK Code Examples

```python
import requests

url = "https://api.prolific.com/api/v1/data-collection/collections/collection_id"

payload = {
    "name": "Updated Skin Type Assessment",
    "task_details": {
        "task_name": "Assess Your Skin Type",
        "task_introduction": "<p>Please answer the following questions about your skin.</p>",
        "task_steps": "<ol><li>Read each question carefully</li><li>Select the most accurate answer</li></ol>"
    },
    "collection_items": [
        {
            "page_items": [
                {
                    "id": "01924850-9e29-744a-811c-b26612812346",
                    "type": "rich_text",
                    "content": "## Section 1: Basic Information"
                },
                {
                    "id": "01924850-9e29-744a-811c-b26612812347",
                    "type": "multiple_choice",
                    "content": "What is your skin type? Select the option that best describes your skin condition throughout the day. This will help us recommend suitable skincare products for you."
                }
            ],
            "id": "01924850-9e29-744a-811c-b26612812345"
        }
    ]
}
headers = {
    "Authorization": "<apiKey>",
    "Content-Type": "application/json"
}

response = requests.put(url, json=payload, headers=headers)

print(response.json())
```

```javascript
const url = 'https://api.prolific.com/api/v1/data-collection/collections/collection_id';
const options = {
  method: 'PUT',
  headers: {Authorization: '<apiKey>', 'Content-Type': 'application/json'},
  body: '{"name":"Updated Skin Type Assessment","task_details":{"task_name":"Assess Your Skin Type","task_introduction":"<p>Please answer the following questions about your skin.</p>","task_steps":"<ol><li>Read each question carefully</li><li>Select the most accurate answer</li></ol>"},"collection_items":[{"page_items":[{"id":"01924850-9e29-744a-811c-b26612812346","type":"rich_text","content":"## Section 1: Basic Information"},{"id":"01924850-9e29-744a-811c-b26612812347","type":"multiple_choice","content":"What is your skin type? Select the option that best describes your skin condition throughout the day. This will help us recommend suitable skincare products for you."}],"id":"01924850-9e29-744a-811c-b26612812345"}]}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.prolific.com/api/v1/data-collection/collections/collection_id"

	payload := strings.NewReader("{\n  \"name\": \"Updated Skin Type Assessment\",\n  \"task_details\": {\n    \"task_name\": \"Assess Your Skin Type\",\n    \"task_introduction\": \"<p>Please answer the following questions about your skin.</p>\",\n    \"task_steps\": \"<ol><li>Read each question carefully</li><li>Select the most accurate answer</li></ol>\"\n  },\n  \"collection_items\": [\n    {\n      \"page_items\": [\n        {\n          \"id\": \"01924850-9e29-744a-811c-b26612812346\",\n          \"type\": \"rich_text\",\n          \"content\": \"## Section 1: Basic Information\"\n        },\n        {\n          \"id\": \"01924850-9e29-744a-811c-b26612812347\",\n          \"type\": \"multiple_choice\",\n          \"content\": \"What is your skin type? Select the option that best describes your skin condition throughout the day. This will help us recommend suitable skincare products for you.\"\n        }\n      ],\n      \"id\": \"01924850-9e29-744a-811c-b26612812345\"\n    }\n  ]\n}")

	req, _ := http.NewRequest("PUT", url, payload)

	req.Header.Add("Authorization", "<apiKey>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.prolific.com/api/v1/data-collection/collections/collection_id")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Put.new(url)
request["Authorization"] = '<apiKey>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"name\": \"Updated Skin Type Assessment\",\n  \"task_details\": {\n    \"task_name\": \"Assess Your Skin Type\",\n    \"task_introduction\": \"<p>Please answer the following questions about your skin.</p>\",\n    \"task_steps\": \"<ol><li>Read each question carefully</li><li>Select the most accurate answer</li></ol>\"\n  },\n  \"collection_items\": [\n    {\n      \"page_items\": [\n        {\n          \"id\": \"01924850-9e29-744a-811c-b26612812346\",\n          \"type\": \"rich_text\",\n          \"content\": \"## Section 1: Basic Information\"\n        },\n        {\n          \"id\": \"01924850-9e29-744a-811c-b26612812347\",\n          \"type\": \"multiple_choice\",\n          \"content\": \"What is your skin type? Select the option that best describes your skin condition throughout the day. This will help us recommend suitable skincare products for you.\"\n        }\n      ],\n      \"id\": \"01924850-9e29-744a-811c-b26612812345\"\n    }\n  ]\n}"

response = http.request(request)
puts response.read_body
```

```java
HttpResponse<String> response = Unirest.put("https://api.prolific.com/api/v1/data-collection/collections/collection_id")
  .header("Authorization", "<apiKey>")
  .header("Content-Type", "application/json")
  .body("{\n  \"name\": \"Updated Skin Type Assessment\",\n  \"task_details\": {\n    \"task_name\": \"Assess Your Skin Type\",\n    \"task_introduction\": \"<p>Please answer the following questions about your skin.</p>\",\n    \"task_steps\": \"<ol><li>Read each question carefully</li><li>Select the most accurate answer</li></ol>\"\n  },\n  \"collection_items\": [\n    {\n      \"page_items\": [\n        {\n          \"id\": \"01924850-9e29-744a-811c-b26612812346\",\n          \"type\": \"rich_text\",\n          \"content\": \"## Section 1: Basic Information\"\n        },\n        {\n          \"id\": \"01924850-9e29-744a-811c-b26612812347\",\n          \"type\": \"multiple_choice\",\n          \"content\": \"What is your skin type? Select the option that best describes your skin condition throughout the day. This will help us recommend suitable skincare products for you.\"\n        }\n      ],\n      \"id\": \"01924850-9e29-744a-811c-b26612812345\"\n    }\n  ]\n}")
  .asString();
```

```php
<?php

$client = new \GuzzleHttp\Client();

$response = $client->request('PUT', 'https://api.prolific.com/api/v1/data-collection/collections/collection_id', [
  'body' => '{
  "name": "Updated Skin Type Assessment",
  "task_details": {
    "task_name": "Assess Your Skin Type",
    "task_introduction": "<p>Please answer the following questions about your skin.</p>",
    "task_steps": "<ol><li>Read each question carefully</li><li>Select the most accurate answer</li></ol>"
  },
  "collection_items": [
    {
      "page_items": [
        {
          "id": "01924850-9e29-744a-811c-b26612812346",
          "type": "rich_text",
          "content": "## Section 1: Basic Information"
        },
        {
          "id": "01924850-9e29-744a-811c-b26612812347",
          "type": "multiple_choice",
          "content": "What is your skin type? Select the option that best describes your skin condition throughout the day. This will help us recommend suitable skincare products for you."
        }
      ],
      "id": "01924850-9e29-744a-811c-b26612812345"
    }
  ]
}',
  'headers' => [
    'Authorization' => '<apiKey>',
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp
var client = new RestClient("https://api.prolific.com/api/v1/data-collection/collections/collection_id");
var request = new RestRequest(Method.PUT);
request.AddHeader("Authorization", "<apiKey>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"name\": \"Updated Skin Type Assessment\",\n  \"task_details\": {\n    \"task_name\": \"Assess Your Skin Type\",\n    \"task_introduction\": \"<p>Please answer the following questions about your skin.</p>\",\n    \"task_steps\": \"<ol><li>Read each question carefully</li><li>Select the most accurate answer</li></ol>\"\n  },\n  \"collection_items\": [\n    {\n      \"page_items\": [\n        {\n          \"id\": \"01924850-9e29-744a-811c-b26612812346\",\n          \"type\": \"rich_text\",\n          \"content\": \"## Section 1: Basic Information\"\n        },\n        {\n          \"id\": \"01924850-9e29-744a-811c-b26612812347\",\n          \"type\": \"multiple_choice\",\n          \"content\": \"What is your skin type? Select the option that best describes your skin condition throughout the day. This will help us recommend suitable skincare products for you.\"\n        }\n      ],\n      \"id\": \"01924850-9e29-744a-811c-b26612812345\"\n    }\n  ]\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "<apiKey>",
  "Content-Type": "application/json"
]
let parameters = [
  "name": "Updated Skin Type Assessment",
  "task_details": [
    "task_name": "Assess Your Skin Type",
    "task_introduction": "<p>Please answer the following questions about your skin.</p>",
    "task_steps": "<ol><li>Read each question carefully</li><li>Select the most accurate answer</li></ol>"
  ],
  "collection_items": [
    [
      "page_items": [
        [
          "id": "01924850-9e29-744a-811c-b26612812346",
          "type": "rich_text",
          "content": "## Section 1: Basic Information"
        ],
        [
          "id": "01924850-9e29-744a-811c-b26612812347",
          "type": "multiple_choice",
          "content": "What is your skin type? Select the option that best describes your skin condition throughout the day. This will help us recommend suitable skincare products for you."
        ]
      ],
      "id": "01924850-9e29-744a-811c-b26612812345"
    ]
  ]
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.prolific.com/api/v1/data-collection/collections/collection_id")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "PUT"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```