diff --git a/config/config.exs b/config/config.exs
index b555247..50c5625 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -33,7 +33,7 @@ config :logger, level: :info
 # Example
 # config :graphql_relay,
 #   schema_module: GraphQL.Schema.Root,
-#   schema_json_path: "#{Path.dirname(__DIR__)}/priv/repo/graphql"
+#   schema_json_path: "#{Path.dirname(__DIR__)}/priv/graphql"
 
 # Import environment specific config. This must remain at the bottom
 # of this file so it overrides the configuration defined above.
diff --git a/examples/todo/config/config.exs b/examples/todo/config/config.exs
index dffd69f..4c61ef5 100644
--- a/examples/todo/config/config.exs
+++ b/examples/todo/config/config.exs
@@ -30,4 +30,4 @@ config :phoenix, :generators,
 
 config :graphql_relay,
   schema_module: Todo.GraphQL.Schema.Root,
-  schema_json_path: "#{Path.dirname(__DIR__)}/priv/repo/graphql"
+  schema_json_path: "#{Path.dirname(__DIR__)}/priv/graphql"
diff --git a/examples/todo/package.json b/examples/todo/package.json
index d11e811..249dbb5 100644
--- a/examples/todo/package.json
+++ b/examples/todo/package.json
@@ -29,7 +29,7 @@
   },
   "metadata": {
     "graphql": {
-      "schema": "./priv/repo/graphql/schema.json"
+      "schema": "./priv/graphql/schema.json"
     }
   }
 }
diff --git a/lib/graphql_relay.ex b/lib/graphql_relay.ex
index 3d383f2..90ab730 100644
--- a/lib/graphql_relay.ex
+++ b/lib/graphql_relay.ex
@@ -20,10 +20,10 @@ defmodule GraphQL.Relay do
     data_dir = Application.fetch_env!(:graphql_relay, :schema_json_path)
 
     File.mkdir_p!(data_dir)
-    File.write!(Path.join(data_dir, "schema.json"), introspection)
+    File.write!(Path.join(data_dir, "schema.json"), introspect)
   end
 
-  defp introspection do
+  def introspect do
     schema_module = Application.fetch_env!(:graphql_relay, :schema_module)
     {_, data} = GraphQL.execute(apply(schema_module, :schema, []), GraphQL.Type.Introspection.query)
     Poison.encode!(data, pretty: true)
diff --git a/lib/mix/tasks/graphql.gen.schema.ex b/lib/mix/tasks/graphql.gen.schema.ex
new file mode 100644
index 0000000..063c90a
--- /dev/null
+++ b/lib/mix/tasks/graphql.gen.schema.ex
@@ -0,0 +1,45 @@
+defmodule Mix.Tasks.Graphql.Gen.SchemaJson do
+  use Mix.Task
+
+  @shortdoc "Generates a `schema.json` file"
+
+  @moduledoc """
+  Creates/updates the GraphQL `schema.json` file.
+
+      mix graphql.gen.schema_json --build brunch
+
+  You can specify which build system you want to trigger a rebuild for.
+  If no build system is specified then no build is triggered.
+
+  ## Command line
+
+    * `--build` - Rebuild the JavaScript. Can be set to one of either:
+
+      * `brunch` - use Brunch. This is the Phoenix default build system.
+
+      * `webpack` - use Webpack
+
+  """
+
+  @doc false
+  @spec run(OptionParser.argv) :: :ok
+  def run(args) do
+    case OptionParser.parse!(args, strict: [build: :string]) do
+      {[], []} ->
+        GraphQL.Relay.generate_schema_json!
+      {[build: build_system], []} ->
+        case build_system do
+          "brunch"  ->
+            GraphQL.Relay.generate_schema_json!
+            System.cmd "brunch", ["build"]
+          "webpack" ->
+            GraphQL.Relay.generate_schema_json!
+            System.cmd "webpack", ["-p"]
+          _ ->
+            Mix.raise("`#{build_system}` is not currently supported.")
+        end
+      {_, _} ->
+        Mix.raise("Invalid options")
+    end
+  end
+end
diff --git a/mix.exs b/mix.exs
index 97ef358..11dfde9 100644
--- a/mix.exs
+++ b/mix.exs
@@ -25,7 +25,7 @@ defmodule GraphQL.Relay.Mixfile do
       applications: [:logger, :ecto],
       env: [
         schema_module: StarWars.Schema, # Module with a .schema function that returns your GraphQL schema
-        schema_json_path: "./schema.json"
+        schema_json_path: "./priv/graphql"
       ]
     ]
   end
diff --git a/test/mix/tasks/graphql.gen.schema_json_test.exs b/test/mix/tasks/graphql.gen.schema_json_test.exs
new file mode 100644
index 0000000..f4bb1f8
--- /dev/null
+++ b/test/mix/tasks/graphql.gen.schema_json_test.exs
@@ -0,0 +1,22 @@
+Code.require_file "../../support/star_wars/data.exs", __DIR__
+Code.require_file "../../support/star_wars/schema.exs", __DIR__
+
+defmodule Mix.Tasks.Graphql.Gen.SchemaJsonTest do
+  use ExUnit.Case, async: true
+
+  test "fails when invalid options given" do
+    assert_raise Mix.Error, "Invalid options", fn ->
+      Mix.Tasks.Graphql.Gen.SchemaJson.run(["invalid"])
+    end
+  end
+
+  test "generates schema.json" do
+    Mix.Tasks.Graphql.Gen.SchemaJson.run([])
+    assert File.read!("priv/graphql/schema.json") == GraphQL.Relay.introspect
+  end
+
+  # test "generates schema.json" do
+  #   Mix.Tasks.Graphql.Gen.SchemaJson.run([])
+  #   assert File.read!("priv/graphql/schema.json") == GraphQL.Relay.introspect
+  # end
+end