requestClientHints

Property Manager name: Request Client Hints
Behavior version: The v2024-10-21 rule format supports the requestClientHints behavior v1.0.
Rule format status: GA, stable
Access: Read/Write
Allowed in includes: Yes

Client hints are HTTP request header fields that determine which resources the browser should include in the response. This behavior configures and prioritizes the client hints you want to send to request specific client and device information.

Use requestClientHints together with the permissionsPolicy behavior.

Option Type Description Requires

Option	Type	Description
`acceptCh`	string array	The client hint data objects you want to receive from the browser. You can add custom entries or provide pre-set values from the list. For more details on each value, see the guide section for this behavior. If you've configured your origin server to pass along data objects, they merge with the ones you set in this array, before the list is sent to the client. Device-Memory Downlink ECT RTT Sec-CH-DPR Sec-CH-UA Sec-CH-UA-Arch Sec-CH-UA-Bitness Sec-CH-UA-Full-Version-List Sec-CH-UA-Mobile Sec-CH-UA-Model Sec-CH-UA-Platform Sec-CH-UA-Platform-Version Sec-CH-Viewport-Width Sec-CH-Width	{"displayType":"string array","tag":"input","todo":true}
`acceptCriticalCh`	string array	The critical client hint data objects you want to receive from the browser. The original request from the browser needs to include these objects. Otherwise, a new response header is sent back to the client, asking for all of these client hint data objects. You can add custom entries or provide pre-set values from the list. For more details on each value, see the guide section for this behavior. Device-Memory Downlink ECT RTT Sec-CH-DPR Sec-CH-UA Sec-CH-UA-Arch Sec-CH-UA-Bitness Sec-CH-UA-Full-Version-List Sec-CH-UA-Mobile Sec-CH-UA-Model Sec-CH-UA-Platform Sec-CH-UA-Platform-Version Sec-CH-Viewport-Width Sec-CH-Width	{"displayType":"string array","tag":"input","todo":true}
`reset`	boolean	This sends an empty instance of the `Accept-CH` response header to clear other `Accept-CH` values currently stored in the client browser. This empty header doesn't get merged with other objects sent from your origin server. To enable this option, make sure you leave `acceptCh` and `acceptCriticalCh` empty.	{"displayType":"boolean","tag":"input","type":"checkbox"}

acceptCh

string array

The client hint data objects you want to receive from the browser. You can add custom entries or provide pre-set values from the list. For more details on each value, see the guide section for this behavior. If you've configured your origin server to pass along data objects, they merge with the ones you set in this array, before the list is sent to the client.

Device-Memory
Downlink
ECT
RTT
Sec-CH-DPR
Sec-CH-UA
Sec-CH-UA-Arch
Sec-CH-UA-Bitness
Sec-CH-UA-Full-Version-List
Sec-CH-UA-Mobile
Sec-CH-UA-Model
Sec-CH-UA-Platform
Sec-CH-UA-Platform-Version
Sec-CH-Viewport-Width
Sec-CH-Width

{"displayType":"string array","tag":"input","todo":true}

acceptCriticalCh

string array

The critical client hint data objects you want to receive from the browser. The original request from the browser needs to include these objects. Otherwise, a new response header is sent back to the client, asking for all of these client hint data objects. You can add custom entries or provide pre-set values from the list. For more details on each value, see the guide section for this behavior.

Device-Memory
Downlink
ECT
RTT
Sec-CH-DPR
Sec-CH-UA
Sec-CH-UA-Arch
Sec-CH-UA-Bitness
Sec-CH-UA-Full-Version-List
Sec-CH-UA-Mobile
Sec-CH-UA-Model
Sec-CH-UA-Platform
Sec-CH-UA-Platform-Version
Sec-CH-Viewport-Width
Sec-CH-Width

{"displayType":"string array","tag":"input","todo":true}

reset

boolean

This sends an empty instance of the Accept-CH response header to clear other Accept-CH values currently stored in the client browser. This empty header doesn't get merged with other objects sent from your origin server.

To enable this option, make sure you leave acceptCh and acceptCriticalCh empty.

{"displayType":"boolean","tag":"input","type":"checkbox"}