diff --git a/app/models/user_api_key_scope.rb b/app/models/user_api_key_scope.rb
index c4f99975009..60a4ca72dcb 100644
--- a/app/models/user_api_key_scope.rb
+++ b/app/models/user_api_key_scope.rb
@@ -12,7 +12,8 @@ class UserApiKeyScope < ActiveRecord::Base
       RouteMatcher.new(methods: :get, actions: 'notifications#index'),
       RouteMatcher.new(methods: :put, actions: 'notifications#mark_read')
     ],
-    session_info: [ RouteMatcher.new(methods: :get, actions: 'session#current') ]
+    session_info: [ RouteMatcher.new(methods: :get, actions: 'session#current') ],
+    bookmarks_calendar: [ RouteMatcher.new(methods: :get, actions: 'users#bookmarks', formats: :ics, params: %i[username]) ]
   }
 
   def self.all_scopes
@@ -20,7 +21,7 @@ class UserApiKeyScope < ActiveRecord::Base
   end
 
   def permits?(env)
-    matchers.any? { |m| m.match?(env: env) }
+    matchers.any? { |m| m.with_allowed_param_values(allowed_parameters).match?(env: env) }
   end
 
   private
@@ -35,11 +36,12 @@ end
 #
 # Table name: user_api_key_scopes
 #
-#  id              :bigint           not null, primary key
-#  user_api_key_id :integer          not null
-#  name            :string           not null
-#  created_at      :datetime         not null
-#  updated_at      :datetime         not null
+#  id                 :bigint           not null, primary key
+#  user_api_key_id    :integer          not null
+#  name               :string           not null
+#  created_at         :datetime         not null
+#  updated_at         :datetime         not null
+#  allowed_parameters :jsonb
 #
 # Indexes
 #
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index a15abb7c68a..786519aa456 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -1049,6 +1049,7 @@ en:
       read: "Read all"
       write: "Write all"
       one_time_password: "Create a one-time login token"
+      bookmarks_calendar: "Read bookmark reminders"
     invalid_public_key: "Sorry, the public key is invalid."
     invalid_auth_redirect: "Sorry, this auth_redirect host is not allowed."
     invalid_token: "Missing, invalid or expired token."
diff --git a/db/migrate/20201008105539_add_allowed_parameters_to_user_api_key_scope.rb b/db/migrate/20201008105539_add_allowed_parameters_to_user_api_key_scope.rb
new file mode 100644
index 00000000000..23c2fae2989
--- /dev/null
+++ b/db/migrate/20201008105539_add_allowed_parameters_to_user_api_key_scope.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddAllowedParametersToUserApiKeyScope < ActiveRecord::Migration[6.0]
+  def change
+    add_column :user_api_key_scopes, :allowed_parameters, :jsonb
+  end
+end
diff --git a/spec/fabricators/user_api_key_fabricator.rb b/spec/fabricators/user_api_key_fabricator.rb
index c6614b95bf9..5d9fe484398 100644
--- a/spec/fabricators/user_api_key_fabricator.rb
+++ b/spec/fabricators/user_api_key_fabricator.rb
@@ -8,3 +8,10 @@ Fabricator(:readonly_user_api_key, from: :user_api_key) do
   client_id { SecureRandom.hex }
   application_name 'some app'
 end
+
+Fabricator(:bookmarks_calendar_user_api_key, from: :user_api_key) do
+  user
+  scopes { [Fabricate.build(:user_api_key_scope, name: 'bookmarks_calendar')] }
+  client_id { SecureRandom.hex }
+  application_name 'some app'
+end
diff --git a/spec/integration/api_keys_spec.rb b/spec/integration/api_keys_spec.rb
index d74378c7e45..db6d9052b9c 100644
--- a/spec/integration/api_keys_spec.rb
+++ b/spec/integration/api_keys_spec.rb
@@ -99,4 +99,33 @@ describe 'user api keys' do
     expect(response.status).to eq(302)
   end
 
+  it "can restrict scopes by parameters" do
+    admin = Fabricate(:admin)
+
+    calendar_key = Fabricate(:bookmarks_calendar_user_api_key, user: admin)
+
+    get "/u/#{user.username}/bookmarks.json", headers: {
+      HTTP_USER_API_KEY: calendar_key.key,
+    }
+    expect(response.status).to eq(403) # Does not allow json
+
+    get "/u/#{user.username}/bookmarks.ics", headers: {
+      HTTP_USER_API_KEY: calendar_key.key,
+    }
+    expect(response.status).to eq(200) # Allows ICS
+
+    # Now restrict the key
+    calendar_key.scopes.first.update(allowed_parameters: { username: admin.username })
+
+    get "/u/#{user.username}/bookmarks.ics", headers: {
+      HTTP_USER_API_KEY: calendar_key.key,
+    }
+    expect(response.status).to eq(403) # Cannot access another users calendar
+
+    get "/u/#{admin.username}/bookmarks.ics", headers: {
+      HTTP_USER_API_KEY: calendar_key.key,
+    }
+    expect(response.status).to eq(200) # Can access own calendar
+  end
+
 end