Real-time collaboration: Add new REST endpoints, setting, and registered post meta by chriszarate · Pull Request #10894 · WordPress/wordpress-develop

chriszarate · 2026-02-10T06:31:41Z

Description

Trac ticket: https://core.trac.wordpress.org/ticket/64622

In Gutenberg, we have added support for real-time collaboration using CRDT documents (via the Yjs library). This work has suggested the following additions to WordPress:

A default "sync provider" based on HTTP polling that allows collaborators to share updates with each other. Previously, we relied on WebRTC connections between collaborators for this purpose, but it proved unreliable under many network conditions.
- Our solution is designed to work on any WordPress installation.
- HTTP polling is the transport we identified as most likely to work universally.
- Given the isolation and lifecycle of PHP processes, updates must be stored centrally in order to be shared among peers. We have chosen to store updates in post meta against a special post type, but alternate storage mechanisms are possible.
- Collaborative editing can involve syncing multiple CRDT documents. To limit the number of connections consumed by this provider, requests are batched.
- To prevent unbounded linear growth, updates are periodically compacted.
- To avoid excessive load on lower-resourced hosts, this provider will benefit from usage limits (e.g., a maximum of three connected collaborators) enforced by the client (Gutenberg).
A new registered post meta that allows Gutenberg to persist CRDT documents alongside posts.
- This provides all collaborators with a "shared starting point" for the collaborative session, which avoids duplicate updates.
- Content stored in the WordPress database always remains the source of truth. If the content differs from the persisted CRDT document, the CRDT document is updated to match the database.
A new Writing setting that allows users to opt-in to real-time collaboration.
- Enabling real-time collaboration disables post lock functionality and connects users to the sync provider.
A behavior change to autosaves is needed. When the the original author is editing a draft post (post_status == 'draft' OR 'auto-draft') and they hold the post lock, the autosave targets the actual post instead of an autosave revision. This puts the post data and the persisted CRDT document out of sync and leads to duplicate updates. When real-time collaboration is enabled, all collaborators must autosave in the same way.

This PR provides a proposed implementation of the changes above. This corresponding Gutenberg PR moves the work from the experimental directory to lib/compat:

WordPress/gutenberg#75366

Cumulative work to add this functionality can be found using this label:

https://github.com/WordPress/gutenberg/issues?q=label%3A%22%5BFeature%5D%20Real-time%20Collaboration%22%20is%3Apr

Testing instructions

Check out this branch.
Update the Gutenberg ref in package.json to 131239e64048aa0f107512129e8b6771c54ba855
Follow the setup instructions in the README.
Settings > Writing > Enable real-time collaboration.
Open a post for editing in two browsers / browser tabs.

github-actions · 2026-02-10T06:31:51Z

Hi @chriszarate! 👋

Thank you for your contribution to WordPress! 💖

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github-actions · 2026-02-10T15:41:13Z

Test using WordPress Playground

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For more details about these limitations and more, check out the Limitations page in the WordPress Playground documentation.

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pkevan · 2026-02-10T15:56:48Z

Is there any tests we can add for the default provider and new functionality?

pkevan · 2026-02-10T15:59:09Z

Can we also provide some documentation on how to override the provider given it's known limitation listed above?

src/wp-includes/collaboration.php

TimothyBJacobs

Why isn't each room a post?

src/wp-includes/collaboration.php

src/wp-includes/collaboration/class-wp-sync-post-meta-storage.php

src/wp-includes/collaboration/class-wp-http-polling-sync-server.php

TimothyBJacobs · 2026-02-10T15:58:43Z

src/wp-includes/collaboration/class-wp-http-polling-sync-server.php

+	 * @param bool   $is_compactor True if this client is nominated to perform compaction.
+	 * @return array Response data for this room.
+	 */
+	private function get_updates_after( string $room, int $client_id, int $cursor, bool $is_compactor ): array {


This seems like it should be a responsibility of the storage layer. If I want to swap with something that can retrieve results ordered by time, we shouldn't have to load all updates always to do that.

I've updated the storage interface and class to take this approach in 9e5cf96. It was a little trickier than I thought, because compaction is an external concern and shouldn't be implemented by storage.

src/wp-includes/collaboration/class-wp-http-polling-sync-server.php

chriszarate · 2026-02-10T16:32:03Z

Why isn't each room a post?

No strong reason. Mostly to avoid creating a large number of posts. Each room corresponds to a synced CRDT document (representing a WordPress entity). Currently supported entity types:

posts (any post type)
taxonomy collections

In the future, this could be expanded to include all database entities, including individual taxonomy terms. We might also create rooms to share awareness data at the page or screen level.

We intend to enforce limits on this default provider, but probably applied to simultaneous collaborators and not on the overall number of synced entities. Sharing a single post felt prudent but happy to reconsider! I know wp_postmeta#meta_key is indexed but I don't have a grasp on the performance tradeoff at large scale.

src/wp-includes/collaboration/class-wp-http-polling-sync-server.php

src/wp-includes/collaboration/class-wp-sync-post-meta-storage.php

src/wp-admin/options-writing.php

src/wp-includes/collaboration/class-wp-http-polling-sync-server.php

src/wp-includes/collaboration/class-wp-sync-post-meta-storage.php

src/wp-includes/collaboration/interface-wp-sync-storage.php

src/wp-includes/collaboration.php

src/wp-includes/post.php

pkevan · 2026-02-17T12:07:57Z

Fix one of the failing unit tests here: chriszarate#1 since I couldn't PR against this.

…ted values The test_get_items test in WP_Test_REST_Settings_Controller hardcodes the expected list of settings exposed via the REST API. The new enable_real_time_collaboration setting was registered with show_in_rest but not added to this expected list, causing the test to fail.

chriszarate · 2026-02-18T03:28:34Z

Note that I've removed the commit that updates Gutenberg to the required version to allow unit tests to pass. The testing instructions have been updated accordingly.

github-actions · 2026-02-18T03:47:55Z

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

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The following contributors have not linked their GitHub and WordPress.org accounts: @gclapps0612-cmd.

Contributors, please read how to link your accounts to ensure your work is properly credited in WordPress releases.

Core Committers: Use this line as a base for the props when committing in SVN:

Props czarate, paulkevan, timothyblynjacobs, westonruter.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

westonruter · 2026-02-18T04:49:31Z

src/wp-includes/collaboration/class-wp-http-polling-sync-server.php

+
+			$entity_kind = $type_parts[0];
+			$entity_name = $object_parts[0];
+			$object_id   = isset( $object_parts[1] ) ? (int) $object_parts[1] : null;


Since the object ID is a string, right?

Suggested change

$object_id = isset( $object_parts[1] ) ? (int) $object_parts[1] : null;

$object_id = $object_parts[1] ?? null;

westonruter · 2026-02-18T04:51:48Z

src/wp-includes/collaboration/class-wp-http-polling-sync-server.php

+			if ( is_wp_error( $merged_awareness ) ) {
+				return $merged_awareness;
+			}


The process_awareness_update method never returns a WP_Error, yeah?

Suggested change

if ( is_wp_error( $merged_awareness ) ) {

return $merged_awareness;

}

westonruter · 2026-02-18T04:52:09Z

src/wp-includes/collaboration/class-wp-http-polling-sync-server.php

+				 * All updates are stored persistently.
+				 */
+				return $this->add_update( $room, $client_id, $type, $data );
+				break;


Suggested change

break;

westonruter · 2026-02-18T04:52:33Z

src/wp-includes/collaboration/class-wp-http-polling-sync-server.php

+	 * @param int    $client_id Client identifier.
+	 * @param string $type      Update type (sync_step1, sync_step2, update, compaction).
+	 * @param string $data      Base64-encoded update data.
+	 * @return bool|WP_Error True on success, WP_Error on storage failure.


Suggested change

* @return bool|WP_Error True on success, WP_Error on storage failure.

* @return true|WP_Error True on success, WP_Error on storage failure.

westonruter · 2026-02-18T04:55:14Z

src/wp-includes/collaboration/class-wp-http-polling-sync-server.php

+	 * @param int    $cursor       Return updates after this cursor.
+	 * @param bool   $is_compactor True if this client is nominated to perform compaction.
+	 * @return array{
+	 *   compaction_request: array|null,


This satisfies the following PHPStan issue:

phpstan: Method WP_HTTP_Polling_Sync_Server::get_updates() return type has no value type specified in iterable type array.

Suggested change

* compaction_request: array|null,

* compaction_request: mixed[]|null,

Actually, this is slightly better:

Suggested change

* compaction_request: array|null,

* compaction_request: array<int, mixed>|null,

It is more explicit, and it satisfies PhpStorm's static analysis complaint as well:

Can be replaced with 'array'

westonruter · 2026-02-18T04:56:00Z

src/wp-includes/collaboration/interface-wp-sync-storage.php

+	 *
+	 * @param string $room   Room identifier.
+	 * @param int    $cursor Return updates after this cursor.
+	 * @return array Sync updates.


This satisfies a PHPStan issue:

phpstan: Method WP_Sync_Storage::get_updates_after_cursor() return type has no value type specified in iterable type array.

Suggested change

* @return array Sync updates.

* @return mixed[] Sync updates.

Suggested change

* @return array Sync updates.

* @return array<int, mixed> Sync updates.

westonruter · 2026-02-18T04:57:07Z

src/wp-includes/collaboration/class-wp-sync-post-meta-storage.php

+	 *
+	 * @param string $room   Room identifier.
+	 * @param int    $cursor Return updates after this cursor.
+	 * @return array Sync updates.


This fixes a PHPStan complaint:

phpstan: Method WP_Sync_Post_Meta_Storage::get_updates_after_cursor() return type has no value type specified in iterable type array.

Suggested change

* @return array Sync updates.

* @return mixed[] Sync updates.

Suggested change

* @return array Sync updates.

* @return array<int, mixed> Sync updates.

pkevan · 2026-02-18T08:36:38Z

src/wp-admin/includes/schema.php

 		'wp_notes_notify'                 => 1,
+
+		// 7.0.0
+		'enable_real_time_collaboration'  => 0,


Suggested change

'enable_real_time_collaboration' => 0,

'enable_real_time_collaboration' => 1,

switch on for beta1

pkevan · 2026-02-18T09:54:37Z

src/wp-includes/option.php

+			'type'              => 'boolean',
+			'description'       => __( 'Enable Real-Time Collaboration' ),
+			'sanitize_callback' => 'rest_sanitize_boolean',
+			'default'           => false,


Suggested change

'default' => false,

'default' => true,

pkevan · 2026-02-18T09:55:58Z

tests/qunit/fixtures/wp-api-generated.js

    "use_smilies": true,
    "default_category": 1,
    "default_post_format": "0",
+    "enable_real_time_collaboration": false,


Suggested change

"enable_real_time_collaboration": false,

"enable_real_time_collaboration": true,

pkevan reviewed Feb 10, 2026

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TimothyBJacobs requested changes Feb 10, 2026

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chriszarate mentioned this pull request Feb 13, 2026

Real-time collaboration: Move PHP code to compat / backports directory WordPress/gutenberg#75366

Merged

github-actions bot mentioned this pull request Feb 13, 2026

PHP backports for WP 7.0 WordPress/gutenberg#74043

Open

chriszarate force-pushed the add/collaboration-functionality branch from 9e5cf96 to 2db6675 Compare February 13, 2026 19:12

ellatrix requested review from TimothyBJacobs and westonruter February 16, 2026 10:48

westonruter requested changes Feb 16, 2026

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pkevan mentioned this pull request Feb 17, 2026

Tests: Add enable_real_time_collaboration to REST settings test #10956

Closed

chriszarate added 4 commits February 17, 2026 09:36

Add setting to enable real-time collaboration

e2105fa

Register collaboration post meta

9922bd4

Add sync provider endpoints

2355a82

Bugfix: When collaboration is enabled, always target autosave revision

9a8cf68

chriszarate force-pushed the add/collaboration-functionality branch from fb2d847 to 92152e8 Compare February 17, 2026 14:49

chriszarate and others added 9 commits February 17, 2026 21:19

Move post meta registration to wp_create_initial_post_meta

663c99c

Move post type registration to create_initial_post_types

479372a

Update REST namespace to match convention

596d70f

Add localization

2bd07db

Use array property notation instead of get_param

331777a

Miscellaneous type fixes

47d473a

Update storage mechanism

59e6316

Fix type hint

47f2f88

chriszarate added 15 commits February 17, 2026 21:19

Type hint and annotation updates

7eee5e2

Add missing label

d004a4a

Improve room input validation

a373cb2

Change const name to remove unit

bd325a9

Add static keyword

c01dc5a

Remove object coercion

1eb9ff8

Return boolean from storage class methods that mutate data

40a5ee8

Improve entity handling around object IDs

2cf1fcd

Account for empty awareness array

13f087b

Simplify timestamp sort

3b1e425

Add missing @SInCE markers

43c5045

Remove unused storage initializer

ce774d2

Update test mocks

b2edf87

Improve return types

65c51f6

Add unit tests

f83467c

chriszarate force-pushed the add/collaboration-functionality branch from 92152e8 to f83467c Compare February 18, 2026 02:21

Guard setAccessible()

db3746e

chriszarate marked this pull request as ready for review February 18, 2026 03:47

chriszarate requested a review from westonruter February 18, 2026 03:56

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pkevan reviewed Feb 18, 2026

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	$object_id = isset( $object_parts[1] ) ? (int) $object_parts[1] : null;
	$object_id = $object_parts[1] ?? null;

	if ( is_wp_error( $merged_awareness ) ) {
	return $merged_awareness;
	}

	* @return bool\|WP_Error True on success, WP_Error on storage failure.
	* @return true\|WP_Error True on success, WP_Error on storage failure.

	* compaction_request: array\|null,
	* compaction_request: mixed[]\|null,

	* compaction_request: array\|null,
	* compaction_request: array<int, mixed>\|null,

	* @return array Sync updates.
	* @return mixed[] Sync updates.

	* @return array Sync updates.
	* @return array<int, mixed> Sync updates.

	'enable_real_time_collaboration' => 0,
	'enable_real_time_collaboration' => 1,

	"enable_real_time_collaboration": false,
	"enable_real_time_collaboration": true,

Conversation

chriszarate commented Feb 10, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Description

Testing instructions

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github-actions bot commented Feb 10, 2026

Test using WordPress Playground

Some things to be aware of

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chriszarate commented Feb 10, 2026 •

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