diff --git a/api/client-server/v2_alpha/tags.yaml b/api/client-server/v2_alpha/tags.yaml
new file mode 100644
index 00000000..91b81212
--- /dev/null
+++ b/api/client-server/v2_alpha/tags.yaml
@@ -0,0 +1,148 @@
+swagger: '2.0'
+info:
+  title: "Matrix Client-Server tag API"
+  version: "1.0.0"
+host: localhost:8008
+schemes:
+  - https
+  - http
+basePath: /_matrix/client/v2_alpha
+consumes:
+  - application/json
+produces:
+  - application/json
+securityDefinitions:
+  accessToken:
+    type: apiKey
+    description: The user_id or application service access_token
+    name: access_token
+    in: query
+paths:
+  "/user/{userId}/rooms/{roomId}/tags":
+    get:
+      summary: List the tags for a room.
+      description: |-
+        List the tags set by a user on a room.
+      security:
+        - accessToken: []
+      parameters:
+        - in: path
+          type: string
+          name: userId
+          required: true
+          description: |-
+            The id of the user to get tags for. The access token must be
+            authorized to make requests for this user id.
+          x-example: "@alice:example.com"
+        - in: path
+          type: string
+          name: roomId
+          required: true
+          description: |-
+            The id of the room to get tags for.
+          x-example: "!726s6s6q:example.com"
+      responses:
+        200:
+          description:
+            The list of tags for the user for the room.
+          schema:
+            type: object
+            properties:
+              tags:
+                type: array
+                items:
+                  type: string
+          examples:
+            application/json: |-
+              {
+                "tags": [
+                  "work",
+                  "pinned"
+                ]
+              }
+  "/user/{userId}/rooms/{roomId}/tags/{tag}":
+    put:
+      summary: Add a tag to a room.
+      description: |-
+        Add a tag to the room.
+      security:
+        - accessToken: []
+      parameters:
+        - in: path
+          type: string
+          name: userId
+          required: true
+          description: |-
+            The id of the user to add a tag for. The access token must be
+            authorized to make requests for this user id.
+          x-example: "@alice:example.com"
+        - in: path
+          type: string
+          name: roomId
+          required: true
+          description: |-
+            The id of the room to add a tag to.
+          x-example: "!726s6s6q:example.com"
+        - in: path
+          type: string
+          name: tag
+          required: true
+          description: |-
+            The tag to add.
+          x-example: "work"
+        - in: body
+          name: body
+          required: true
+          description: |-
+            An empty JSON object.
+          schema:
+            type: object
+            example: |-
+              {}
+      responses:
+        200:
+          description:
+            The tag was successfully added.
+          schema:
+            type: object
+          examples:
+            application/json: |-
+              {}
+    delete:
+      summary: Remove a tag from the room.
+      description: |-
+        Remove a tag from the room.
+      security:
+        - access_token: []
+      parameters:
+        - in: path
+          type: string
+          name: userId
+          required: true
+          description: |-
+            The id of the user to remove a tag for. The access token must be
+            authorized to make requests for this user id.
+          x-example: "@alice:example.com"
+        - in: path
+          type: string
+          name: roomId
+          required: true
+          description: |-
+            The id of the room to remove a tag from.
+          x-example: "!726s6s6q:example.com"
+        - in: path
+          type: string
+          name: tag
+          required: true
+          description: |-
+            The tag to remove.
+          x-example: "work"
+      responses:
+        200:
+          description:
+            The tag was successfully removed
+          schema:
+            type: object
+          examples:
+            application/json: |-
+              {}
diff --git a/event-schemas/examples/v1/m.tag b/event-schemas/examples/v1/m.tag
new file mode 100644
index 00000000..28431b73
--- /dev/null
+++ b/event-schemas/examples/v1/m.tag
@@ -0,0 +1,8 @@
+{
+  "type": "m.tag",
+  "content": {
+    "tags": [
+      "work"
+    ]
+  }
+}
diff --git a/event-schemas/schema/v1/m.tag b/event-schemas/schema/v1/m.tag
new file mode 100644
index 00000000..235d442d
--- /dev/null
+++ b/event-schemas/schema/v1/m.tag
@@ -0,0 +1,23 @@
+{
+  "type": "object",
+  "title": "Tag Event",
+  "description": "Informs the client of tags on a room.",
+  "properties": {
+    "type": {
+      "type": "string",
+      "enum": ["m.tag"]
+    },
+    "content": {
+      "type": "object",
+      "properties": {
+        "tags": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        }
+      }
+    }
+  },
+ "required": ["type", "content"]
+}
diff --git a/specification/modules/room_tagging.rst b/specification/modules/room_tagging.rst
new file mode 100644
index 00000000..76fff125
--- /dev/null
+++ b/specification/modules/room_tagging.rst
@@ -0,0 +1,21 @@
+Room Tagging
+============
+
+.. _module:tagging:
+
+Users can add tags to rooms. Tags are short strings used to label rooms, e.g.
+"work", "familly". A room may have multiple tags. Tags are only visible to the
+user that set them but are shared across all their devices.
+
+Events
+------
+
+The tags on a room are passed as single ``m.tag`` event in the ``ephemeral``
+section of a v2 room sync.
+
+{{m_tag_event}}
+
+Client Behaviour
+----------------
+
+{{v2_tags_http_api}}