Permissions-Policy: language-model directive

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The HTTP Permissions-Policy header language-model directive controls access to the Prompt API.

Specifically, where a defined policy blocks usage, the LanguageModel.availability() static method will return unavailable, and any attempts to call other LanguageModel methods will fail with a NotAllowedError DOMException.

Syntax

http
Permissions-Policy: language-model=<allowlist>;
<allowlist>

A list of origins for which permission is granted to use the feature. See Permissions-Policy > Syntax for more details.

Default policy

The default allowlist for language-model is self. The top-level browsing context and same-origin iframes are allowed access to the Prompt API by default.

Examples

Basic usage

SecureCorp Inc. wants to disallow language-model within all cross-origin iframes except those whose origin is https://example.com. It can do so by delivering the following HTTP response header to define a Permissions Policy:

http
Permissions-Policy: language-model=(self "https://example.com")

SecureCorp Inc. must also include an allow attribute on each <iframe> element where language-model is to be allowed:

html
<iframe src="https://example.com/blue" allow="language-model"></iframe>

Note: Specifying the Permissions-Policy header in this manner disallows language-model for other origins, even if they are allowed by the <iframe> allow attribute.

Using the default policy

If an allowlist for language-model is not defined by a Permissions-Policy response header, user agents will apply the default allowlist self. In this mode, language-model is automatically allowed in the top-level browsing context and same-origin iframes, but not in cross-origin iframes.

To allow language-model in a cross-origin iframe, include an allow attribute on the <iframe> element:

html
<iframe src="https://other.com/blue" allow="language-model"></iframe>

Specifications

Specification
Prompt API
# permissions-policy

Browser compatibility

See also