Jetpack AI: Adding translation support using Chrome's Gemini AI mini

[mwatson]

Fixes #41212

Proposed changes:

• Adds support for Chrome AI (Gemini mini) for translations
• This is behind a feature flag and in beta (see test instructions for more)
• This should be fairly seamless for users, meaning if a translation cannot be done by Gemini it will fall back to our original translation method
• Note: I had to disable typescript-eslint/no-explicit-any for some lines because Typescript refused to compile without the as any code but the linter also rejected those lines. I couldn't figure out a way to satisfy both so I decided to disable the linter since that's less mission critical.
• See test instructions for more info / limitations

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
• Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

No product discussion but the PT is here: pe4Cmx-30R-p2

Does this pull request change what data or activity we track or use?

No

Testing instructions:

• Two options:

  • Easy mode: If you plan to test using jurassic.ninja I have created a token that you can find on Slack: p1739311387984089/1739302089.335769-slack-C054LN8RNVA
  • If you want to test elsewhere (locally, or somewhere else with Jetpack beta, perhaps) you will have to sign up for the trial and get your own token.
    • Sign up here: https://developer.chrome.com/origintrials/#/view_trial/4445615782168100865
    • Instructions are here: https://developer.chrome.com/docs/ai/translator-api#get_started

• Once you have a token you can continue with the next steps:

• Check out this branch, add the following snippet to enable beta features, the feature flag, and add your token in place of [ your trial token goes here]:

define( 'JETPACK_BLOCKS_VARIATION', 'beta' );
add_filter( 'ai_chrome_ai_enabled', '__return_true' );

$token_transient_name = 'jetpack-ai-chrome-ai-token';
if ( ! get_transient( $token_transient_name ) ) {
	set_transient(
		$token_transient_name,
		"[ your trial token goes here ]",
		3600
	);
}

• This snippet should also make it so you don't have to modify your sandbox to return your trial token. However for the duration of the trial we will have to ask WPCOM for the token. Currently there is no general purpose token, which is why this setup is required for testing.
• Once this is set up you should be able to translate using Chrome.
• Open the javascript console and enable debug mode.
• Create a new post and add some text. Try to translate it as you normally would into a supported language
  • Supported languages can be found here: https://developer.chrome.com/docs/ai/translator-api#supported-languages
  • Note that for the trial Chrome will only download two language packs, so if you attempt to translate to more than two languages the third supported language will use OpenAI translations instead.
• As long as the language is supported by Chrome (all of my testing was done by translating to Spanish), you should not see the translation streamed from OpenAI as you normally would in the console. However the text should be replaced with the language you selected. There may be a small delay while Chrome downloads the language pack.
• Revert /reject the changes and observe that the paragraph goes back to the previous language
• Try to translate it to an unsupported language (French or German are what I normally use) and observe that the translation goes through OpenAI and you see the translation streamed in the console.
• Try out various languages and translations, revert, change back, etc, and take not of any weird or unexpected behavior.
• Disable the feature flag and observe that translating to a supported language now goes through OpenAI with a streamed response

[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WordPress.com Simple site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin, and enable the change/add-chrome-ai-translate-support branch.

• To test on Simple, run the following command on your sandbox:

  bin/jetpack-downloader test jetpack change/add-chrome-ai-translate-support
  

Interested in more tips and information?

• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
• Read more about our development workflow here: PCYsg-eg0-p2
• Figure out when your changes will be shipped to customers here: PCYsg-eg5-p2

[github-actions]

Thank you for your PR!

When contributing to Jetpack, we have a few suggestions that can help us test and review your patch:

• ✅ Include a description of your PR changes.
  
• ✅ Add a "[Status]" label (In Progress, Needs Team Review, ...).
  
• ✅ Add a "[Type]" label (Bug, Enhancement, Janitorial, Task).
  
• ✅ Add testing instructions.
  
• ✅ Specify whether this PR includes any changes to data or privacy.
  
• ✅ Add changelog entries to affected projects
  

This comment will be updated as you work on your PR and make changes. If you think that some of those checks are not needed for your PR, please explain why you think so. Thanks for cooperation 🤖

---

The e2e test report can be found here. Please note that it can take a few minutes after the e2e tests checks are complete for the report to be available.

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Follow this PR Review Process:

1. Ensure all required checks appearing at the bottom of this PR are passing.
2. Choose a review path based on your changes:
   • A. Team Review: add the "[Status] Needs Team Review" label
     • For most changes, including minor cross-team impacts.
     • Example: Updating a team-specific component or a small change to a shared library.
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     • Example: Refactor affecting multiple systems.
3. Get at least one approval before merging.

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---

Jetpack plugin:

The Jetpack plugin has different release cadences depending on the platform:

• WordPress.com Simple releases happen semi-continuously (PCYsg-Jjm-p2).
• WoA releases happen weekly.
• Releases to self-hosted sites happen monthly. The next release is scheduled for none scheduled (scheduled code freeze on undefined).

If you have any questions about the release process, please ask in the #jetpack-releases channel on Slack.

[github-actions]

Code Coverage Summary

Coverage changed in 2 files.

File	Coverage	Δ%	Δ Uncovered
projects/plugins/jetpack/extensions/blocks/ai-assistant/ai-assistant.php	0/95 (0.00%)	0.00%	38 💔
projects/js-packages/ai-client/src/hooks/use-ai-suggestions/index.ts	0/84 (0.00%)	0.00%	3 ❤️‍🩹

3 files are newly checked for coverage.

File	Coverage
projects/js-packages/ai-client/src/chrome-ai/factory.ts	0/27 (0.00%) 💔
projects/js-packages/ai-client/src/chrome-ai/suggestions.ts	0/30 (0.00%) 💔
projects/js-packages/ai-client/src/chrome-ai/index.ts	0/0 (—%) 🤷

Full summary · PHP report · JS report

_{Add label I don't care about code coverage for this PR Use this label to ignore the check for insufficient code coveage. to override the failing coverage check.}