---
schema_version: "1"
id: 04631bd62e4e9f2581985e6340b53926b709a2313a4dd198f199f956cf740303
title: ConnectApi.ExtensionInput
collection: legacydeveloper
version: current
locale: en-us
portal_url: https://docs.salesforce.com/legacydeveloper/current/en-us/apexref/apex_connectapi_input_extension.md
canonical_url: https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_connectapi_input_extension.htm
source_site: developer.salesforce.com
content_type: documentation
content_hash: 9ed010d54a037c48b6afad5b060229afe76f0592b0573c090858833a746ba5b7
description: An extension.
---
# ConnectApi.ExtensionInput

An extension.

| Property | Type | Description | Required or Optional | Available Version |
| --- | --- | --- | --- | --- |
| alternative​Representation | [ConnectApi.AlternativeInput](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_connectapi_input_alternative.htm "Alternative representation for an extension on a feed element.") | Alternative representation of the extension. | Required | 40.0 |
| extensionId | String | ID of the extension. | Required | 40.0 |
| payload | String | Payload associated with the extension. | Required | 40.0 |
| payloadVersion | String | Payload version that identifies the structure of the payload associated with the extension. | Optional | 40.0 |

#### See Also

- [ConnectApi.ExtensionsCapabilityInput](https://developer.salesforce.com/docs/atlas.en-us.apexref.meta/apexref/apex_connectapi_input_extensions_capability.htm "Create or update extensions associated with a feed element.")