diff --git a/src/activity-vocabulary.lisp b/src/activity-vocabulary.lisp
new file mode 100644
index 0000000..9194e38
--- /dev/null
+++ b/src/activity-vocabulary.lisp
@@ -0,0 +1,81 @@
+;;;; activity-vocabulary: Classes for ActivityVocabulary types.
+
+;; Copyright © 2024 Jaidyn Ann <jadedctrl@posteo.at>
+;;
+;; This program is free software: you can redistribute it and/or
+;; modify it under the terms of the GNU General Public License as
+;; published by the Free Software Foundation, either version 3 of
+;; the License, or (at your option) any later version.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+(defpackage #:activitypub-servist/activity-vocabulary
+  (:use #:cl)
+  (:nicknames "AP-S/AV" "AV"))
+
+(in-package #:activitypub-servist/activity-vocabulary)
+
+
+;;; Macros
+;;; ————————————————————————————————————————
+(defmacro defclass-w-accessors (name direct-superclasses slots &rest options)
+  `(defclass ,name ,direct-superclasses
+     ,(mapcar
+       (lambda (slot)
+         (typecase slot
+           (list slot)
+           (t (list slot :accessor slot :initarg (intern (symbol-name slot) "KEYWORD")))))
+       slots)
+     ,@options))
+
+
+
+;;; Core types
+;;; ————————————————————————————————————————
+;; https://www.w3.org/ns/activitystreams#Object
+(defclass-w-accessors av-object ()
+  (
+   attachment attributed-to audience bcc bto cc content context
+   duration end-time generator icon image in-reply-to location
+   media-type name preview published replies start-time summary
+   tag to updated url))
+
+;; https://www.w3.org/ns/activitystreams#Link
+(defclass-w-accessors av-link ()
+  (height href hreflang media-type name preview rel width))
+
+;; https://www.w3.org/ns/activitystreams#Activity
+(defclass-w-accessors av-activity (av-object)
+  (actor instrument object origin result target))
+
+;; Should be ordinary Activity, sans `object`.
+;; https://www.w3.org/ns/activitystreams#IntransitiveActivity
+(defclass av-intransitive-activity (av-activity) ())
+
+;; https://www.w3.org/ns/activitystreams#Collection
+(defclass-w-accessors av-collection (av-object)
+  (current first items last total-items))
+
+;; https://www.w3.org/ns/activitystreams#OrderedCollection
+(defclass av-ordered-collection (av-collection) ())
+
+;; https://www.w3.org/ns/activitystreams#CollectionPage
+(defclass-w-accessors av-collection-page (av-collection)
+   (next part-of prev))
+
+;; https://www.w3.org/ns/activitystreams#OrderedCollectionPage
+(defclass-w-accessors av-ordered-collection-page (av-collection-page)
+  (startIndex))
+
+
+
+
+;;; Extended Activity types
+;;; ————————————————————————————————————————
+(defclass-w-accessors av-