diff --git a/lib/scopes/storage.ex b/lib/scopes/storage.ex
new file mode 100644
index 0000000..0ec722a
--- /dev/null
+++ b/lib/scopes/storage.ex
@@ -0,0 +1,104 @@
+defmodule Scopes.Storage do
+  @moduledoc """
+  The Storage context.
+  """
+
+  import Ecto.Query, warn: false
+  alias Scopes.Repo
+
+  alias Scopes.Storage.Concept
+
+  @doc """
+  Returns the list of concepts.
+
+  ## Examples
+
+      iex> list_concepts()
+      [%Concept{}, ...]
+
+  """
+  def list_concepts do
+    Repo.all(Concept)
+  end
+
+  @doc """
+  Gets a single concept.
+
+  Raises `Ecto.NoResultsError` if the Concept does not exist.
+
+  ## Examples
+
+      iex> get_concept!(123)
+      %Concept{}
+
+      iex> get_concept!(456)
+      ** (Ecto.NoResultsError)
+
+  """
+  def get_concept!(id), do: Repo.get!(Concept, id)
+
+  @doc """
+  Creates a concept.
+
+  ## Examples
+
+      iex> create_concept(%{field: value})
+      {:ok, %Concept{}}
+
+      iex> create_concept(%{field: bad_value})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def create_concept(attrs) do
+    %Concept{}
+    |> Concept.changeset(attrs)
+    |> Repo.insert()
+  end
+
+  @doc """
+  Updates a concept.
+
+  ## Examples
+
+      iex> update_concept(concept, %{field: new_value})
+      {:ok, %Concept{}}
+
+      iex> update_concept(concept, %{field: bad_value})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def update_concept(%Concept{} = concept, attrs) do
+    concept
+    |> Concept.changeset(attrs)
+    |> Repo.update()
+  end
+
+  @doc """
+  Deletes a concept.
+
+  ## Examples
+
+      iex> delete_concept(concept)
+      {:ok, %Concept{}}
+
+      iex> delete_concept(concept)
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def delete_concept(%Concept{} = concept) do
+    Repo.delete(concept)
+  end
+
+  @doc """
+  Returns an `%Ecto.Changeset{}` for tracking concept changes.
+
+  ## Examples
+
+      iex> change_concept(concept)
+      %Ecto.Changeset{data: %Concept{}}
+
+  """
+  def change_concept(%Concept{} = concept, attrs \\ %{}) do
+    Concept.changeset(concept, attrs)
+  end
+end
diff --git a/lib/scopes/storage/concept.ex b/lib/scopes/storage/concept.ex
new file mode 100644
index 0000000..88860f1
--- /dev/null
+++ b/lib/scopes/storage/concept.ex
@@ -0,0 +1,20 @@
+defmodule Scopes.Storage.Concept do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  schema "concepts" do
+    field :domain, :string
+    field :class, :string
+    field :item, :string
+    field :data, :map
+
+    timestamps(type: :utc_datetime)
+  end
+
+  @doc false
+  def changeset(concept, attrs) do
+    concept
+    |> cast(attrs, [:domain, :class, :item, :data])
+    |> validate_required([:domain, :class, :item])
+  end
+end
diff --git a/lib/scopes_web/controllers/changeset_json.ex b/lib/scopes_web/controllers/changeset_json.ex
new file mode 100644
index 0000000..e91a465
--- /dev/null
+++ b/lib/scopes_web/controllers/changeset_json.ex
@@ -0,0 +1,25 @@
+defmodule ScopesWeb.ChangesetJSON do
+  @doc """
+  Renders changeset errors.
+  """
+  def error(%{changeset: changeset}) do
+    # When encoded, the changeset returns its errors
+    # as a JSON object. So we just pass it forward.
+    %{errors: Ecto.Changeset.traverse_errors(changeset, &translate_error/1)}
+  end
+
+  defp translate_error({msg, opts}) do
+    # You can make use of gettext to translate error messages by
+    # uncommenting and adjusting the following code:
+
+    # if count = opts[:count] do
+    #   Gettext.dngettext(ScopesWeb.Gettext, "errors", msg, msg, count, opts)
+    # else
+    #   Gettext.dgettext(ScopesWeb.Gettext, "errors", msg, opts)
+    # end
+
+    Enum.reduce(opts, msg, fn {key, value}, acc ->
+      String.replace(acc, "%{#{key}}", fn _ -> to_string(value) end)
+    end)
+  end
+end
diff --git a/lib/scopes_web/controllers/concept_controller.ex b/lib/scopes_web/controllers/concept_controller.ex
new file mode 100644
index 0000000..2f60c15
--- /dev/null
+++ b/lib/scopes_web/controllers/concept_controller.ex
@@ -0,0 +1,43 @@
+defmodule ScopesWeb.ConceptController do
+  use ScopesWeb, :controller
+
+  alias Scopes.Storage
+  alias Scopes.Storage.Concept
+
+  action_fallback ScopesWeb.FallbackController
+
+  def index(conn, _params) do
+    concepts = Storage.list_concepts()
+    render(conn, :index, concepts: concepts)
+  end
+
+  def create(conn, %{"concept" => concept_params}) do
+    with {:ok, %Concept{} = concept} <- Storage.create_concept(concept_params) do
+      conn
+      |> put_status(:created)
+      |> put_resp_header("location", ~p"/api/concepts/#{concept}")
+      |> render(:show, concept: concept)
+    end
+  end
+
+  def show(conn, %{"id" => id}) do
+    concept = Storage.get_concept!(id)
+    render(conn, :show, concept: concept)
+  end
+
+  def update(conn, %{"id" => id, "concept" => concept_params}) do
+    concept = Storage.get_concept!(id)
+
+    with {:ok, %Concept{} = concept} <- Storage.update_concept(concept, concept_params) do
+      render(conn, :show, concept: concept)
+    end
+  end
+
+  def delete(conn, %{"id" => id}) do
+    concept = Storage.get_concept!(id)
+
+    with {:ok, %Concept{}} <- Storage.delete_concept(concept) do
+      send_resp(conn, :no_content, "")
+    end
+  end
+end
diff --git a/lib/scopes_web/controllers/concept_json.ex b/lib/scopes_web/controllers/concept_json.ex
new file mode 100644
index 0000000..3f0273a
--- /dev/null
+++ b/lib/scopes_web/controllers/concept_json.ex
@@ -0,0 +1,27 @@
+defmodule ScopesWeb.ConceptJSON do
+  alias Scopes.Storage.Concept
+
+  @doc """
+  Renders a list of concepts.
+  """
+  def index(%{concepts: concepts}) do
+    %{data: for(concept <- concepts, do: data(concept))}
+  end
+
+  @doc """
+  Renders a single concept.
+  """
+  def show(%{concept: concept}) do
+    %{data: data(concept)}
+  end
+
+  defp data(%Concept{} = concept) do
+    %{
+      id: concept.id,
+      domain: concept.domain,
+      class: concept.class,
+      item: concept.item,
+      data: concept.data
+    }
+  end
+end
diff --git a/lib/scopes_web/controllers/fallback_controller.ex b/lib/scopes_web/controllers/fallback_controller.ex
new file mode 100644
index 0000000..e5c1d49
--- /dev/null
+++ b/lib/scopes_web/controllers/fallback_controller.ex
@@ -0,0 +1,24 @@
+defmodule ScopesWeb.FallbackController do
+  @moduledoc """
+  Translates controller action results into valid `Plug.Conn` responses.
+
+  See `Phoenix.Controller.action_fallback/1` for more details.
+  """
+  use ScopesWeb, :controller
+
+  # This clause handles errors returned by Ecto's insert/update/delete.
+  def call(conn, {:error, %Ecto.Changeset{} = changeset}) do
+    conn
+    |> put_status(:unprocessable_entity)
+    |> put_view(json: ScopesWeb.ChangesetJSON)
+    |> render(:error, changeset: changeset)
+  end
+
+  # This clause is an example of how to handle resources that cannot be found.
+  def call(conn, {:error, :not_found}) do
+    conn
+    |> put_status(:not_found)
+    |> put_view(html: ScopesWeb.ErrorHTML, json: ScopesWeb.ErrorJSON)
+    |> render(:"404")
+  end
+end
diff --git a/lib/scopes_web/router.ex b/lib/scopes_web/router.ex
index 31d4e8f..5446905 100644
--- a/lib/scopes_web/router.ex
+++ b/lib/scopes_web/router.ex
@@ -26,9 +26,10 @@ defmodule ScopesWeb.Router do
   end
 
   # Other scopes may use custom stacks.
-  # scope "/api", ScopesWeb do
-  #   pipe_through :api
-  # end
+    scope "/api", ScopesWeb do
+      pipe_through :api
+      resources "/concepts", ConceptController, except: [:new, :edit]
+    end
 
   # Enable LiveDashboard and Swoosh mailbox preview in development
   if Application.compile_env(:scopes, :dev_routes) do
diff --git a/priv/repo/migrations/20260530121444_create_concepts.exs b/priv/repo/migrations/20260530121444_create_concepts.exs
new file mode 100644
index 0000000..4e0904d
--- /dev/null
+++ b/priv/repo/migrations/20260530121444_create_concepts.exs
@@ -0,0 +1,14 @@
+defmodule Scopes.Repo.Migrations.CreateConcepts do
+  use Ecto.Migration
+
+  def change do
+    create table(:concepts) do
+      add :domain, :string
+      add :class, :string
+      add :item, :string
+      add :data, :map
+
+      timestamps(type: :utc_datetime)
+    end
+  end
+end
diff --git a/test/scopes/storage_test.exs b/test/scopes/storage_test.exs
new file mode 100644
index 0000000..8b5066f
--- /dev/null
+++ b/test/scopes/storage_test.exs
@@ -0,0 +1,65 @@
+defmodule Scopes.StorageTest do
+  use Scopes.DataCase
+
+  alias Scopes.Storage
+
+  describe "concepts" do
+    alias Scopes.Storage.Concept
+
+    import Scopes.StorageFixtures
+
+    @invalid_attrs %{data: nil, domain: nil, item: nil, class: nil}
+
+    test "list_concepts/0 returns all concepts" do
+      concept = concept_fixture()
+      assert Storage.list_concepts() == [concept]
+    end
+
+    test "get_concept!/1 returns the concept with given id" do
+      concept = concept_fixture()
+      assert Storage.get_concept!(concept.id) == concept
+    end
+
+    test "create_concept/1 with valid data creates a concept" do
+      valid_attrs = %{data: %{}, domain: "some domain", item: "some item", class: "some class"}
+
+      assert {:ok, %Concept{} = concept} = Storage.create_concept(valid_attrs)
+      assert concept.data == %{}
+      assert concept.domain == "some domain"
+      assert concept.item == "some item"
+      assert concept.class == "some class"
+    end
+
+    test "create_concept/1 with invalid data returns error changeset" do
+      assert {:error, %Ecto.Changeset{}} = Storage.create_concept(@invalid_attrs)
+    end
+
+    test "update_concept/2 with valid data updates the concept" do
+      concept = concept_fixture()
+      update_attrs = %{data: %{}, domain: "some updated domain", item: "some updated item", class: "some updated class"}
+
+      assert {:ok, %Concept{} = concept} = Storage.update_concept(concept, update_attrs)
+      assert concept.data == %{}
+      assert concept.domain == "some updated domain"
+      assert concept.item == "some updated item"
+      assert concept.class == "some updated class"
+    end
+
+    test "update_concept/2 with invalid data returns error changeset" do
+      concept = concept_fixture()
+      assert {:error, %Ecto.Changeset{}} = Storage.update_concept(concept, @invalid_attrs)
+      assert concept == Storage.get_concept!(concept.id)
+    end
+
+    test "delete_concept/1 deletes the concept" do
+      concept = concept_fixture()
+      assert {:ok, %Concept{}} = Storage.delete_concept(concept)
+      assert_raise Ecto.NoResultsError, fn -> Storage.get_concept!(concept.id) end
+    end
+
+    test "change_concept/1 returns a concept changeset" do
+      concept = concept_fixture()
+      assert %Ecto.Changeset{} = Storage.change_concept(concept)
+    end
+  end
+end
diff --git a/test/scopes_web/controllers/concept_controller_test.exs b/test/scopes_web/controllers/concept_controller_test.exs
new file mode 100644
index 0000000..a4ee868
--- /dev/null
+++ b/test/scopes_web/controllers/concept_controller_test.exs
@@ -0,0 +1,96 @@
+defmodule ScopesWeb.ConceptControllerTest do
+  use ScopesWeb.ConnCase
+
+  import Scopes.StorageFixtures
+  alias Scopes.Storage.Concept
+
+  @create_attrs %{
+    data: %{},
+    domain: "some domain",
+    item: "some item",
+    class: "some class"
+  }
+  @update_attrs %{
+    data: %{},
+    domain: "some updated domain",
+    item: "some updated item",
+    class: "some updated class"
+  }
+  @invalid_attrs %{data: nil, domain: nil, item: nil, class: nil}
+
+  setup %{conn: conn} do
+    {:ok, conn: put_req_header(conn, "accept", "application/json")}
+  end
+
+  describe "index" do
+    test "lists all concepts", %{conn: conn} do
+      conn = get(conn, ~p"/api/concepts")
+      assert json_response(conn, 200)["data"] == []
+    end
+  end
+
+  describe "create concept" do
+    test "renders concept when data is valid", %{conn: conn} do
+      conn = post(conn, ~p"/api/concepts", concept: @create_attrs)
+      assert %{"id" => id} = json_response(conn, 201)["data"]
+
+      conn = get(conn, ~p"/api/concepts/#{id}")
+
+      assert %{
+               "id" => ^id,
+               "class" => "some class",
+               "data" => %{},
+               "domain" => "some domain",
+               "item" => "some item"
+             } = json_response(conn, 200)["data"]
+    end
+
+    test "renders errors when data is invalid", %{conn: conn} do
+      conn = post(conn, ~p"/api/concepts", concept: @invalid_attrs)
+      assert json_response(conn, 422)["errors"] != %{}
+    end
+  end
+
+  describe "update concept" do
+    setup [:create_concept]
+
+    test "renders concept when data is valid", %{conn: conn, concept: %Concept{id: id} = concept} do
+      conn = put(conn, ~p"/api/concepts/#{concept}", concept: @update_attrs)
+      assert %{"id" => ^id} = json_response(conn, 200)["data"]
+
+      conn = get(conn, ~p"/api/concepts/#{id}")
+
+      assert %{
+               "id" => ^id,
+               "class" => "some updated class",
+               "data" => %{},
+               "domain" => "some updated domain",
+               "item" => "some updated item"
+             } = json_response(conn, 200)["data"]
+    end
+
+    test "renders errors when data is invalid", %{conn: conn, concept: concept} do
+      conn = put(conn, ~p"/api/concepts/#{concept}", concept: @invalid_attrs)
+      assert json_response(conn, 422)["errors"] != %{}
+    end
+  end
+
+  describe "delete concept" do
+    setup [:create_concept]
+
+    test "deletes chosen concept", %{conn: conn, concept: concept} do
+      conn = delete(conn, ~p"/api/concepts/#{concept}")
+      assert response(conn, 204)
+
+      assert_error_sent 404, fn ->
+        get(conn, ~p"/api/concepts/#{concept}")
+      end
+    end
+  end
+
+  defp create_concept(_) do
+    concept = concept_fixture()
+
+    %{concept: concept}
+  end
+end
diff --git a/test/support/fixtures/storage_fixtures.ex b/test/support/fixtures/storage_fixtures.ex
new file mode 100644
index 0000000..ff0ddf7
--- /dev/null
+++ b/test/support/fixtures/storage_fixtures.ex
@@ -0,0 +1,23 @@
+defmodule Scopes.StorageFixtures do
+  @moduledoc """
+  This module defines test helpers for creating
+  entities via the `Scopes.Storage` context.
+  """
+
+  @doc """
+  Generate a concept.
+  """
+  def concept_fixture(attrs \\ %{}) do
+    {:ok, concept} =
+      attrs
+      |> Enum.into(%{
+        class: "some class",
+        data: %{},
+        domain: "some domain",
+        item: "some item"
+      })
+      |> Scopes.Storage.create_concept()
+
+    concept
+  end
+end