diff --git a/lib/travis/api/v3.rb b/lib/travis/api/v3.rb
index 221df59b..8c8be745 100644
--- a/lib/travis/api/v3.rb
+++ b/lib/travis/api/v3.rb
@@ -34,6 +34,7 @@ module Travis
       ServerError         = Error              .create(status: 500)
       NotImplemented      = ServerError        .create('request not (yet) implemented', status: 501)
       RequestLimitReached = ClientError        .create('request limit reached for resource', status: 429)
+      AlreadySyncing      = ClientError        .create('sync already in progress', status: 409)
     end
   end
 end
diff --git a/lib/travis/api/v3/access_control/generic.rb b/lib/travis/api/v3/access_control/generic.rb
index 0e31d723..c232f879 100644
--- a/lib/travis/api/v3/access_control/generic.rb
+++ b/lib/travis/api/v3/access_control/generic.rb
@@ -83,6 +83,10 @@ module Travis::API::V3
       unrestricted_api?
     end
 
+    def user_writable?(user)
+      self.user == user
+    end
+
     def repository_visible?(repository)
       return true if unrestricted_api? and not repository.private?
       private_repository_visible?(repository)
diff --git a/lib/travis/api/v3/queries/user.rb b/lib/travis/api/v3/queries/user.rb
index 47bd7f02..72db91a1 100644
--- a/lib/travis/api/v3/queries/user.rb
+++ b/lib/travis/api/v3/queries/user.rb
@@ -1,6 +1,7 @@
 module Travis::API::V3
   class Queries::User < Query
-    params :id, :login, :email, :github_id
+    setup_sidekiq(:user_sync, queue: :user_sync, class_name: "Travis::GithubSync::Workers::SyncUser")
+    params :id, :login, :email, :github_id, :is_syncing
 
     def find
       return Models::User.find_by_id(id) if id
@@ -17,5 +18,12 @@ module Travis::API::V3
         User.find_by_email(email)
       end
     end
+
+    def sync(user)
+      raise AlreadySyncing if user.is_syncing?
+      perform_async(:user_sync, user.id)
+      user.update_column(:is_syncing, true)
+      user
+    end
   end
 end
diff --git a/lib/travis/api/v3/query.rb b/lib/travis/api/v3/query.rb
index e4ea4f09..97d803ba 100644
--- a/lib/travis/api/v3/query.rb
+++ b/lib/travis/api/v3/query.rb
@@ -1,6 +1,18 @@
 module Travis::API::V3
   class Query
-    @@sidekiq_cache = Tool::ThreadLocal.new
+    @@sidekiq_queue = {}
+
+    def self.sidekiq_queue(identifier)
+      @@sidekiq_queue[identifier] ||= [
+        "Travis::Sidekiq::#{identifier.to_s.camelcase}".freeze,
+        identifier.to_s.pluralize.freeze
+      ]
+    end
+
+    def self.setup_sidekiq(identifier, queue: nil, class_name: nil)
+      sidekiq_queue(identifier)[0] = class_name if class_name
+      sidekiq_queue(identifier)[1] = queue      if queue
+    end
 
     # generate from eval to avoid additional string allocations on every params access
     @@params_accessor = <<-RUBY
@@ -90,11 +102,7 @@ module Travis::API::V3
     end
 
     def perform_async(identifier, *args)
-      class_name, queue = @@sidekiq_cache[identifier] ||= [
-        "Travis::Sidekiq::#{identifier.to_s.camelcase}".freeze,
-        identifier.to_s.pluralize.freeze
-      ]
-
+      class_name, queue = Query.sidekiq_queue(identifier)
       ::Sidekiq::Client.push('queue'.freeze => queue, 'class'.freeze => class_name, 'args'.freeze => args)
     end
 
diff --git a/lib/travis/api/v3/routes.rb b/lib/travis/api/v3/routes.rb
index 37eb7699..d58d8970 100644
--- a/lib/travis/api/v3/routes.rb
+++ b/lib/travis/api/v3/routes.rb
@@ -118,6 +118,7 @@ module Travis::API::V3
       route '/user'
       get :current
       get :find, '/{user.id}'
+      post :sync, '/{user.id}/sync'
     end
 
   end
diff --git a/lib/travis/api/v3/services/user/sync.rb b/lib/travis/api/v3/services/user/sync.rb
new file mode 100644
index 00000000..5ece301b
--- /dev/null
+++ b/lib/travis/api/v3/services/user/sync.rb
@@ -0,0 +1,12 @@
+module Travis::API::V3
+  class Services::User::Sync < Service
+
+    def run!
+      raise LoginRequired unless access_control.logged_in? or access_control.full_access?
+      raise NotFound      unless user = find(:user)
+      access_control.permissions(user).sync!
+
+      query.sync(user)
+    end
+  end
+end
diff --git a/spec/v3/services/user/sync_spec.rb b/spec/v3/services/user/sync_spec.rb
new file mode 100644
index 00000000..316d41f9
--- /dev/null
+++ b/spec/v3/services/user/sync_spec.rb
@@ -0,0 +1,110 @@
+require 'spec_helper'
+
+describe Travis::API::V3::Services::User::Sync do
+  let(:user)  { Travis::API::V3::Models::User.find_by_login('svenfuchs') }
+  let(:user2) { Travis::API::V3::Models::User.create(login: 'carlad', is_syncing: true) }
+  let(:sidekiq_payload) { JSON.load(Sidekiq::Client.last['args'].last.to_json) }
+  let(:sidekiq_params)  { Sidekiq::Client.last['args'].last.deep_symbolize_keys }
+
+  before do
+    user.update_attribute(:is_syncing, false)
+    Travis::Features.stubs(:owner_active?).returns(true)
+    @original_sidekiq = Sidekiq::Client
+    Sidekiq.send(:remove_const, :Client) # to avoid a warning
+    Sidekiq::Client = []
+  end
+
+  after do
+    Sidekiq.send(:remove_const, :Client) # to avoid a warning
+    Sidekiq::Client = @original_sidekiq
+  end
+
+  describe "not authenticated" do
+    before  { post("/v3/user/#{user.id}/sync") }
+    example { expect(last_response.status).to be == 403 }
+    example { expect(JSON.load(body)).to      be ==     {
+      "@type"         => "error",
+      "error_type"    => "login_required",
+      "error_message" => "login required"
+    }}
+  end
+
+  describe "missing user, authenticated" do
+    let(:token)   { Travis::Api::App::AccessToken.create(user: user, app_id: 1) }
+    let(:headers) {{ 'HTTP_AUTHORIZATION' => "token #{token}" }}
+    before        { post("/v3/user/9999999999/sync", {}, headers) }
+
+    example { expect(last_response.status).to be == 404 }
+    example { expect(JSON.load(body)).to      be ==     {
+      "@type"         => "error",
+      "error_type"    => "not_found",
+      "error_message" => "user not found (or insufficient access)",
+      "resource_type" => "user"
+    }}
+  end
+
+  describe "existing user, matches current user " do
+    let(:params)  {{}}
+    let(:token)   { Travis::Api::App::AccessToken.create(user: user, app_id: 1) }
+    let(:headers) {{ 'HTTP_AUTHORIZATION' => "token #{token}" }}
+    before        { Travis::API::V3::Models::Permission.create(user: user) }
+    before        { post("/v3/user/#{user.id}/sync", params, headers) }
+
+    example { expect(last_response.status).to be == 200 }
+    example { expect(JSON.load(body).to_s).to include(
+      "@type",
+      "user",
+      "@href",
+      "@representation",
+      "sync",
+      "is_syncing",
+      "id",
+      "true")
+    }
+
+    example { expect(sidekiq_payload).to be == user.id }
+
+    example { expect(Sidekiq::Client.last['queue']).to be == :user_sync                }
+    example { expect(Sidekiq::Client.last['class']).to be == 'Travis::GithubSync::Workers::SyncUser' }
+  end
+
+  describe "existing user, current user does not have sync access " do
+    let(:params)  {{}}
+    let(:token)   { Travis::Api::App::AccessToken.create(user: user, app_id: 1) }
+    let(:headers) {{ 'HTTP_AUTHORIZATION' => "token #{token}" }}
+    before        { Travis::API::V3::Models::Permission.create(user: user) }
+    before        { post("/v3/user/#{user2.id}/sync", params, headers) }
+
+    example { expect(last_response.status).to be == 403 }
+    example { expect(JSON.load(body)).to be == {
+      "@type"         => "error",
+      "error_type"    => "insufficient_access",
+      "error_message" => "operation requires sync access to user",
+      "resource_type" => "user",
+      "permission"    => "sync",
+      "user"          => {
+        "@type"       => "user",
+        "@href"       => "/user/#{user2.id}",
+        "@representation"=> "minimal",
+        "id"          => user2.id,
+        "login"       => "carlad"
+      }
+    }}
+  end
+
+  describe "existing user, authorized, user already syncing " do
+    let(:params)  {{}}
+    let(:token)   { Travis::Api::App::AccessToken.create(user: user2, app_id: 1) }
+    let(:headers) {{ 'HTTP_AUTHORIZATION' => "token #{token}" }}
+    before        { Travis::API::V3::Models::Permission.create(user: user) }
+    before        { post("/v3/user/#{user2.id}/sync", params, headers) }
+
+    example { expect(last_response.status).to be == 409 }
+    example { expect(JSON.load(body)).to be == {
+      "@type"         => "error",
+      "error_type"    => "already_syncing",
+      "error_message" => "sync already in progress"
+      }
+    }
+  end
+end