Use Agents Manager state endpoint

[jom]

Fixes AI-850
Paired with 202452-ghe-Automattic/wpcom

Proposed changes:

• Switches the Agents Manager Jetpack proxy (WP_REST_Agents_Manager_Persisted_Open_State) from the general /me/preferences endpoint to the new dedicated /wpcom/v2/agents-manager/state endpoint.
• Removes the calypso_preferences wrapper from both request and response handling — the new endpoint uses flat key/value format.
• Extracts a DEFAULTS constant for fallback values, reducing duplication between get_state and set_state.
• Updates class-agents-manager.php to fetch the unified_ai_chat preference from /agents-manager/state instead of /me/preferences.
• Updates test mocks to match the new endpoint URL.

Why are these changes being made?

• The general /me/preferences endpoint exposes all calypso preferences, which is unnecessarily broad for Agents Manager.
• On Jetpack-connected sites, the proxy forwards user-token-authenticated requests to wpcom. Using a dedicated scoped endpoint follows the principle of least privilege — only the Agents Manager keys are accessible.
• The new endpoint also validates value types on write (booleans, enum for position, structured object for router history).

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)?

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

No

Testing instructions:

See Automattic/wp-calypso#108636 for testing instructions

[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 WoA dev 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 (WordPress.com Site Helper), and enable the change/use-wpcom-agents-manager-endpoint branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack-mu-wpcom-plugin change/use-wpcom-agents-manager-endpoint

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]

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[jp-launch-control]

Code Coverage Summary

Coverage changed in 1 file.

File	Coverage	Δ%	Δ Uncovered
projects/packages/jetpack-mu-wpcom/src/features/agents-manager/class-wp-rest-agents-manager-persisted-open-state.php	18/63 (28.57%)	5.19%	-14 💚

Full summary · PHP report

[Copilot]

Pull request overview

This PR updates the Agents Manager feature to use a new dedicated /wpcom/v2/agents-manager/state API endpoint instead of the general /me/preferences endpoint. The change follows the principle of least privilege by limiting access to only the specific Agents Manager preferences rather than all Calypso preferences.

Changes:

• Switched REST API proxy endpoint from /me/preferences to /agents-manager/state for persisted state management
• Removed calypso_preferences wrapper from request/response handling in favor of flat key-value format with a state parameter
• Extracted a DEFAULTS constant to reduce duplication and centralize default values

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
class-wp-rest-agents-manager-persisted-open-state.php	Updated to use new /agents-manager/state endpoint, removed calypso_preferences wrapper, added DEFAULTS constant, improved error handling
class-agents-manager.php	Updated fetch_unified_experience_preference() to call /agents-manager/state?key=unified_ai_chat with updated comments
Agents_Manager_Test.php	Updated test mocks to check for new endpoint URL /agents-manager/state
changelog entry	Added changelog entry documenting the endpoint migration

[Copilot]

The response parsing logic appears incorrect. According to the comment, the response should be { "unified_ai_chat": true/false } when using the key param, but the code uses ! empty( $decoded_body ) which will return true for any non-empty response object, regardless of the actual value of unified_ai_chat.

For example, if the API returns { "unified_ai_chat": false }, this code will incorrectly evaluate to true because the array is not empty. The code should explicitly check the value: $result = ! empty( $decoded_body['unified_ai_chat'] );

Suggested change

	$result = ! empty( $decoded_body );
	$result = is_array( $decoded_body ) && ! empty( $decoded_body['unified_ai_chat'] );