Extension:ActivityWiki

**MediaWiki extensions manual**
ActivityWiki; Release status: stable
Implementation	Database
Description	Integrates a MediaWiki instance with the Fediverse via ActivityPub
Author(s)	Luca Mauri
Latest version	1.1.0
MediaWiki	1.41+
PHP	8.0+
Database changes	Yes
Composer	lucamauri/activitywiki
	Tables activitywiki_activities; ; activitywiki_followers; ; activitywiki_keys;
Licence	GNU General Public License 2.0 or later
Download	GitHub: project page; git repository URL; commit history; ; Note:; No localisation updates are; provided by translatewiki.net. ; https://github.com/lucamauri/ActivityWiki/blob/main/README.md

ActivityWiki is a MediaWiki extension that integrates a wiki installation with the Fediverse via the ActivityPub W3C protocol. The wiki presents itself as a Fediverse actor, similar to a Mastodon account: Mastodon users and other Fediverse participants can follow the wiki and receive notifications directly in their Fediverse timeline whenever pages are created, edited, or deleted.

Features

A fully-formed ActivityPub actor object, discoverable via WebFinger (RFC 7033)
HTTP Signature signing (draft-cavage-http-signatures-12) on all outbound requests, using a self-managed RSA key pair
Automatic federation of page creations, edits, deletions, and moves as Create/Update/Delete activities
A real, database-backed outbox and followers collection
Incoming Follow/Undo|Follow handling, with automatic Accept replies
Configurable per-namespace federation, excerpt length, and delivery retry behaviour
A maintenance script for manual key generation and rotation

All five ActivityPub-spec-required endpoints (actor, WebFinger, outbox, followers, inbox) are implemented and have been verified live against real Fediverse traffic (Mastodon).

Requirements

Requirement	Minimum version
MediaWiki	1.41
PHP	8.0
Database	MySQL / MariaDB
Web server	Apache or Nginx, with the ability to add a rewrite rule (required for WebFinger — see below)

Installation

Option A — Git

cd extensions/
git clone https://github.com/lucamauri/ActivityWiki.git ActivityWiki

Option B — Composer / Packagist

ActivityWiki is published on Packagist as lucamauri/activitywiki. If your MediaWiki installation is Composer-managed at the root, run this from the installation root (not the extensions/ directory):

composer require lucamauri/activitywiki

The package declares itself as a MediaWiki extension type, so the composer/installers plugin (bundled with MediaWiki core by default) places it directly into extensions/ActivityWiki/ automatically.

Common steps (either installation method)

Add to LocalSettings.php:

wfLoadExtension( 'ActivityWiki' );

Run the database update script:

php maintenance/run.php update.php

Set up WebFinger routing — this step is required; without it the wiki is invisible to Fediverse search even though every other endpoint functions correctly. See WebFinger routing below.

Configuration

All configuration variables are optional; defaults are shown below.

Variable	Default	Description
`$wgActivityWikiEnabled`	`true`	Master switch — disable to pause all federation without uninstalling.
`$wgActivityWikiActorName`	`null`	Display name shown on Mastodon and other Fediverse clients. Defaults to `$wgSitename`.
`$wgActivityWikiActorUsername`	`null`	The handle for the wiki actor (the part before `@domain`). Defaults to a slugified `$wgSitename`.
`$wgActivityWikiActorSummary`		Short bio shown on the Mastodon profile.
`$wgActivityWikiActorIcon`	`null`	Absolute URL to the wiki logo used as the actor avatar. Defaults to `$wgFavicon`.
`$wgActivityWikiKeySize`	`2048`	RSA key size in bits for HTTP Signature key generation. Minimum 2048, recommended 4096.
`$wgActivityWikiPublishNamespaces`	`[ NS_MAIN ]`	Array of namespace constants to federate.
`$wgActivityWikiPublishCreations`	`true`	Federate page creations as `Create` activities.
`$wgActivityWikiPublishEdits`	`true`	Federate page edits as `Update` activities.
`$wgActivityWikiPublishDeletions`	`true`	Federate page deletions as `Delete` activities.
`$wgActivityWikiPublishMoves`	`true`	Federate page moves/renames as `Update` activities.
`$wgActivityWikiPublishMinorEdits`	`false`	Whether minor edits are federated. Suppressed by default.
`$wgActivityWikiPublishProtections`	`false`	Whether page protection changes are federated.
`$wgActivityWikiExcerptLength`	`500`	Maximum plain-text excerpt length (characters) included in activities.
`$wgActivityWikiDeliveryRetries`	`3`	Retry attempts for failed HTTP deliveries (outbound activities and Accept replies).
`$wgActivityWikiOutboxLimit`	`20`	Maximum number of activities returned by the outbox endpoint (most recent first). Does not affect the reported `totalItems` count.
`$wgActivityWikiEnableUserActors`	`false`	Enable per-user ActivityPub actors. Post-MVP, not yet implemented — do not enable in production.
`$wgActivityWikiDebugLevel`	`0`	Debug logging level (0 = off, 1 = verbose).

To see ActivityWiki's debug log output, add a dedicated log channel:

$wgDebugLogGroups['ActivityWiki'] = '/path/to/your/logs/ActivityWiki.log';

WebFinger routing

The WebFinger protocol (RFC 7033) requires requests to be served from a fixed, well-known path at the root of your domain:

https://yourdomain.org/.well-known/webfinger?resource=acct:user@yourdomain.org

This path sits outside MediaWiki's normal URL space, so MediaWiki cannot serve it on its own. Two things are required: the bundled entry-point script, and a web-server rewrite rule pointing to it.

Why a separate entry-point file is needed

MediaWiki's REST router validates that every incoming REQUEST_URI starts with the REST base path. A plain web-server-level rewrite from /.well-known/webfinger straight to the REST path is not enough on its own, since the rewrite happens after PHP has already read $_SERVER['REQUEST_URI']. The bundled entry-points/webfinger.php corrects $_SERVER['REQUEST_URI'] itself before MediaWiki boots, then hands off to rest.php.

Apache

RewriteRule ^\.well-known/webfinger$ %{DOCUMENT_ROOT}/webfinger.php [QSA,L]

Do not anchor the pattern with a leading / — inside a <VirtualHost> block, Apache's RewriteRule matches the URL path without a leading slash.

Nginx

location = /.well-known/webfinger {
    fastcgi_param REQUEST_URI /your-script-path/rest.php/activitywiki/webfinger;
    fastcgi_param QUERY_STRING $query_string;
}

Full step-by-step instructions, including reverse-proxy notes (Anubis, Varnish, Cloudflare) and a troubleshooting table, are in the project README.

Key rotation

The RSA key pair used for HTTP Signature signing is generated automatically on first install. A maintenance script, maintenance/GenerateKeys.php, is available for manual generation and rotation:

# First-time generation / safe check (no existing key required):
php maintenance/run.php extensions/ActivityWiki/maintenance/GenerateKeys.php

# Deliberate rotation of an existing key (destructive, requires --force):
php maintenance/run.php extensions/ActivityWiki/maintenance/GenerateKeys.php --force

Rotating an existing key is gated behind --force since it immediately invalidates the previous key — remote servers with a cached copy of the old public key may continue rejecting signed requests until their cache expires.