> For the complete documentation index, see [llms.txt](https://guardian.hedera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guardian.hedera.com/docs/3.5.1/guardian/standard-registry/policies/policy-creation/introduction/dropdown-block-addon-dropdownblockaddon.md).
# Dropdown Block Addon (dropdownBlockAddon)
The purpose of this block is to display an interactive dropdown menu in the interfaceDocumentsSourceBlock.
## Usage
As shown in the example below, dropdownBlockAddon blocks should be placed inside interfaceDocumentsSourceBlock blocks. Source addons, which return documents for the dropdown, should be placed inside dropdownBlockAddon.
## Properties
| Property Name | Description | Example | Status |
| ---------------------------- | ----------------------------------------------------------------------------- | ----------------------------------- | ------ |
| Option Name (*optionName*) | The label (name) which is shown in dropdown items. | document.credentialSubject.0.field0 | |
| Option Value (*optionValue*) | The value which will be used when a specific item is clicked. | document.credentialSubject.0.id | |
| Field (*field*) | The field in selected document which will be populated with the option value. | assignedTo | |
## Events
Dropdown block addon events will be automatically added to document source.
## API
The API for the dropdownBlockAddon has both GET and POST methods:
1. Example response to the GET request:
```
{
"id": "47169fdc-900f-4e07-abb4-5510d7be1175",
"blockType": "dropdownBlockAddon",
"optionName": "document.credentialSubject.0.field0",
"optionValue": "document.credentialSubject.0.id",
"field": "assignedTo",
"documents": [
{
"name": "example",
"optionValue": "did:hedera:testnet:9XvzF671JeyoVRg8PvSZBTTyKyrvnZu2Mz7qE6FZXY8P_0.0.4481265",
"value": "66b28683d029375c10f0f4ef"
}
],
}
```
A response to the GET request includes all block settings and:
● documents - Dropdown options
2. Example payload for the POST request:
```
{
"documentId": "66b28672d029375c10f0f4b6",
"dropdownDocumentId": "66b28683d029375c10f0f4ef"
}
```
● documentId - Selected document
● dropdownDocumentId - Dropdown item which was clicked
---
# Agent Instructions
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## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.
Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:
```
GET https://guardian.hedera.com/docs/3.5.1/guardian/standard-registry/policies/policy-creation/introduction/dropdown-block-addon-dropdownblockaddon.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.
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