diff --git a/doc/specs/schemas/UserActivity.yaml b/doc/specs/schemas/UserActivity.yaml
new file mode 100644
index 0000000..81b4c24
--- /dev/null
+++ b/doc/specs/schemas/UserActivity.yaml
@@ -0,0 +1,203 @@
+type: object
+
+properties:
+  interval:
+    type: object
+    required:
+      - start
+      - end
+    properties:
+      start:
+        type: number
+      end:
+        type: number
+  games:
+    type: object
+    properties:
+      chess960:
+        $ref: './UserActivityScore.yaml'
+      atomic:
+        $ref: './UserActivityScore.yaml'
+      racingKings:
+        $ref: './UserActivityScore.yaml'
+      ultraBullet:
+        $ref: './UserActivityScore.yaml'
+      blitz:
+        $ref: './UserActivityScore.yaml'
+      kingOfTheHill:
+        $ref: './UserActivityScore.yaml'
+      bullet:
+        $ref: './UserActivityScore.yaml'
+      correspondence:
+        $ref: './UserActivityScore.yaml'
+      horde:
+        $ref: './UserActivityScore.yaml'
+      puzzle:
+        $ref: './UserActivityScore.yaml'
+      classical:
+        $ref: './UserActivityScore.yaml'
+      rapid:
+        $ref: './UserActivityScore.yaml'
+
+  puzzles:
+    type: object
+    properties:
+      score:
+        $ref: './UserActivityScore.yaml'
+
+  storm:
+    type: object
+    properties:
+      runs:
+        type: number
+      score:
+        type: number
+  racer:
+    type: object
+    properties:
+      runs:
+        type: number
+      score:
+        type: number
+  streak:
+    type: object
+    properties:
+      runs:
+        type: number
+      score:
+        type: number
+  tournaments:
+    type: object
+    properties:
+      nb:
+        type: number
+      best:
+        type: array
+        items:
+          type: object
+          required:
+            - tournament
+            - nbGames
+            - score
+            - rank
+            - rankPercent
+          properties:
+            tournament:
+              type: object
+              required:
+                - id
+                - name
+              properties:
+                id:
+                  type: string
+                name:
+                  type: string
+            nbGames:
+              type: number
+            score:
+              type: number
+            rank:
+              type: number
+            rankPercent:
+              type: number
+  practice:
+    type: array
+    items:
+      type: object
+      required:
+        - url
+        - name
+        - nbPositions
+      properties:
+        url:
+          type: string
+        name:
+          type: string
+        nbPositions:
+          type: number
+  simuls:
+    type: array
+    items:
+      type: string
+  correspondenceMoves:
+    type: object
+    required:
+      - nb
+      - games
+    properties:
+      nb:
+        type: number
+      games:
+        type: array
+        items:
+          $ref: './UserActivityCorrespondenceGame.yaml'
+  correspondenceEnds:
+    type: object
+    required:
+      - score
+      - games
+    properties:
+      score:
+        $ref: './UserActivityScore.yaml'
+      games:
+        type: array
+        items:
+          $ref: './UserActivityCorrespondenceGame.yaml'
+  follows:
+    type: object
+    properties:
+      in:
+        $ref: './UserActivityFollowList.yaml'
+      out:
+        $ref: './UserActivityFollowList.yaml'
+  studies:
+    type: object
+  teams:
+    type: array
+    items:
+      type: object
+      required:
+        - url
+        - name
+      properties:
+        url:
+          type: string
+        name:
+          type: string
+  posts:
+    type: array
+    items:
+      type: object
+      required:
+        - topicUrl
+        - topicName
+        - posts
+      properties:
+        topicUrl:
+          type: string
+        topicName:
+          type: string
+        posts:
+          type: array
+          items:
+            type: object
+            required:
+              - url
+              - text
+            properties:
+              url:
+                type: string
+              text:
+                type: string
+  patron:
+    type: object
+    required:
+      - months
+    properties:
+      months:
+        type: number
+  stream:
+    type: boolean
+
+required:
+  - interval
diff --git a/doc/specs/schemas/UserActivityCorrespondenceGame.yaml b/doc/specs/schemas/UserActivityCorrespondenceGame.yaml
new file mode 100644
index 0000000..568ca73
--- /dev/null
+++ b/doc/specs/schemas/UserActivityCorrespondenceGame.yaml
@@ -0,0 +1,40 @@
+type: object
+
+properties:
+  id:
+    type: string
+  color:
+    type: string
+    enum: ['white', 'black']
+  url:
+    type: string
+  variant:
+    $ref: './VariantKey.yaml'
+  speed:
+    type: string
+    const: correspondence
+  perf:
+    type: string
+    const: correspondence
+  rated:
+    type: boolean
+  opponent:
+    type: object
+    required:
+      - user
+      - rating
+    properties:
+      user:
+        type: string
+      rating:
+        type: number
+
+required:
+  - id
+  - color
+  - url
+  - variant
+  - speed
+  - perf
+  - rated
+  - opponent
diff --git a/doc/specs/schemas/UserActivityFollowList.yaml b/doc/specs/schemas/UserActivityFollowList.yaml
new file mode 100644
index 0000000..65104cf
--- /dev/null
+++ b/doc/specs/schemas/UserActivityFollowList.yaml
@@ -0,0 +1,12 @@
+type: object
+
+properties:
+  ids:
+    type: array
+    items:
+      type: string
+  nb:
+    type: number
+
+required:
+  - ids
diff --git a/doc/specs/schemas/UserActivityScore.yaml b/doc/specs/schemas/UserActivityScore.yaml
new file mode 100644
index 0000000..9fbff48
--- /dev/null
+++ b/doc/specs/schemas/UserActivityScore.yaml
@@ -0,0 +1,22 @@
+type: object
+
+properties:
+  win:
+    type: number
+  loss:
+    type: number
+  draw:
+    type: number
+  rp:
+    type: object
+    properties:
+      before:
+        type: number
+      after:
+        type: number
+
+required:
+  - win
+  - loss
+  - draw
+  - rp
diff --git a/doc/specs/tags/users/api-user-username-activity.yaml b/doc/specs/tags/users/api-user-username-activity.yaml
index 8750bdf..23e0ab6 100644
--- a/doc/specs/tags/users/api-user-username-activity.yaml
+++ b/doc/specs/tags/users/api-user-username-activity.yaml
@@ -13,7 +13,7 @@ get:
         type: string
       required: true
   responses:
-    "200":
+    '200':
       description: The activity feed of the user.
       headers:
         Access-Control-Allow-Origin:
@@ -22,5 +22,6 @@ get:
             default: "'*'"
       content:
         application/json:
-          example:
-            https://gist.github.com/ornicar/0ee2d2427cb74ed1a35e86f5ba09fabc
+          schema:
+            $ref: '../../schemas/UserActivity.yaml'
+            example: 'https://gist.github.com/ornicar/0ee2d2427cb74ed1a35e86f5ba09fabc'