diff --git a/lib/sanbase/project/list/selector/project_list_selector.ex b/lib/sanbase/project/list/selector/project_list_selector.ex
index 35000f5d58..0fca0bfb18 100644
--- a/lib/sanbase/project/list/selector/project_list_selector.ex
+++ b/lib/sanbase/project/list/selector/project_list_selector.ex
@@ -91,6 +91,7 @@ defmodule Sanbase.Project.ListSelector do
     order_by = Transform.args_to_order_by(args)
     pagination = Transform.args_to_pagination(args)
     filters_combinator = Transform.args_to_filters_combinator(args)
+    include_hidden = Map.get(args, :include_hidden, false)
 
     base_slugs = base_slugs(base_projects_selector)
 
@@ -105,7 +106,8 @@ defmodule Sanbase.Project.ListSelector do
         pagination: pagination,
         min_volume: Map.get(args, :min_volume),
         included_slugs: included_slugs,
-        ordered_slugs: ordered_slugs
+        ordered_slugs: ordered_slugs,
+        include_hidden: include_hidden
       ]
 
       {:ok, opts}
diff --git a/lib/sanbase/project/project.ex b/lib/sanbase/project/project.ex
index dbfc878151..aabaed3b59 100644
--- a/lib/sanbase/project/project.ex
+++ b/lib/sanbase/project/project.ex
@@ -33,6 +33,8 @@ defmodule Sanbase.Project do
     field(:slug, :string)
     field(:coinmarketcap_id, :string)
     field(:is_hidden, :boolean, default: false)
+    field(:hidden_since, :utc_datetime)
+    field(:hidden_reason, :string)
 
     field(:description, :string)
     field(:long_description, :string)
@@ -123,6 +125,8 @@ defmodule Sanbase.Project do
       :github_link,
       :infrastructure_id,
       :is_hidden,
+      :hidden_since,
+      :hidden_reason,
       :linkedin_link,
       :logo_url,
       :long_description,
@@ -149,6 +153,22 @@ defmodule Sanbase.Project do
     |> cast_assoc(:market_segments)
     |> cast_assoc(:ecosystems)
     |> unique_constraint(:slug)
+    |> maybe_add_hidden_since()
+  end
+
+  defp maybe_add_hidden_since(changeset) do
+    case changeset.changes do
+      %{is_hidden: true} ->
+        changeset
+        |> put_change(:hidden_since, DateTime.utc_now() |> DateTime.truncate(:second))
+
+      %{is_hiden: false} ->
+        changeset
+        |> put_change(:hidden_since, nil)
+
+      _ ->
+        changeset
+    end
   end
 
   defdelegate roi_usd(project), to: Project.Roi
diff --git a/lib/sanbase_web/generic_admin/project.ex b/lib/sanbase_web/generic_admin/project.ex
index 4d60334478..c715335c8d 100644
--- a/lib/sanbase_web/generic_admin/project.ex
+++ b/lib/sanbase_web/generic_admin/project.ex
@@ -27,6 +27,7 @@ defmodule SanbaseWeb.GenericAdmin.Project do
         :infrastructure,
         :token_decimals,
         :is_hidden,
+        :hidden_reason,
         :telegram_chat_id,
         :logo_url,
         :dark_logo_url,
@@ -61,6 +62,7 @@ defmodule SanbaseWeb.GenericAdmin.Project do
         :infrastructure,
         :token_decimals,
         :is_hidden,
+        :hidden_reason,
         :telegram_chat_id,
         :logo_url,
         :dark_logo_url,
diff --git a/lib/sanbase_web/graphql/schema/queries/project_queries.ex b/lib/sanbase_web/graphql/schema/queries/project_queries.ex
index c40e3d2b7e..545bfad3ab 100644
--- a/lib/sanbase_web/graphql/schema/queries/project_queries.ex
+++ b/lib/sanbase_web/graphql/schema/queries/project_queries.ex
@@ -25,6 +25,8 @@ defmodule SanbaseWeb.Graphql.Schema.ProjectQueries do
       arg(:page_size, :integer)
       arg(:min_volume, :integer)
 
+      arg(:include_hidden, :boolean, default_value: false)
+
       middleware(ProjectPermissions)
       cache_resolve(&ProjectListResolver.all_projects/3)
     end
diff --git a/lib/sanbase_web/graphql/schema/types/project_types.ex b/lib/sanbase_web/graphql/schema/types/project_types.ex
index 8e884aa947..2ef9f84ee5 100644
--- a/lib/sanbase_web/graphql/schema/types/project_types.ex
+++ b/lib/sanbase_web/graphql/schema/types/project_types.ex
@@ -359,6 +359,32 @@ defmodule SanbaseWeb.Graphql.ProjectTypes do
     field(:long_description, :string)
     field(:token_decimals, :integer)
 
+    @desc ~s"""
+    Shows if a project is marked as hidden.
+
+    Hidden projects are excluded from lists of projects
+    like allProjects and screeners that are filtered by a condition.
+
+    Hidden projects can be accessed when directly queried via project or projectBySlug,
+    or by passing the `includeHiddenProjects: true` flag to `allProjects`.
+    """
+    field(:is_hidden, non_null(:boolean))
+
+    @desc ~s"""
+    If the project is hidden, this field shows the datetime since which the project
+    is hidden.
+
+    Not all hidden projects have a hidden_since field. The projects that are hidden
+    before August 2024 don't have their hidden_since stored.
+    """
+    field(:hidden_since, :datetime)
+
+    @desc ~s"""
+    If the project is hidden, this field can contain the reason why the project is
+    hidden.
+    """
+    field(:hidden_reason, :string)
+
     @desc ~s"""
     A full list of all the ecosystem this project contributes to
     in one or more ways:
diff --git a/priv/repo/migrations/20240809122904_extend_projects_table_hidden_info.exs b/priv/repo/migrations/20240809122904_extend_projects_table_hidden_info.exs
new file mode 100644
index 0000000000..5e2618396b
--- /dev/null
+++ b/priv/repo/migrations/20240809122904_extend_projects_table_hidden_info.exs
@@ -0,0 +1,10 @@
+defmodule Sanbase.Repo.Migrations.ExtendProjectsTableHiddenInfo do
+  use Ecto.Migration
+
+  def change do
+    alter table(:project) do
+      add(:hidden_since, :utc_datetime)
+      add(:hidden_reason, :text)
+    end
+  end
+end
diff --git a/priv/repo/structure.sql b/priv/repo/structure.sql
index 2791645e4c..b7f72f80c1 100644
--- a/priv/repo/structure.sql
+++ b/priv/repo/structure.sql
@@ -2902,7 +2902,9 @@ CREATE TABLE public.project (
     ecosystem character varying(255),
     ecosystem_full_path character varying(255),
     multichain_project_group_key character varying(255) DEFAULT NULL::character varying,
-    deployed_on_ecosystem_id bigint
+    deployed_on_ecosystem_id bigint,
+    hidden_since timestamp(0) without time zone,
+    hidden_reason text
 );
 
 
@@ -9559,3 +9561,4 @@ INSERT INTO public."schema_migrations" (version) VALUES (20240531121027);
 INSERT INTO public."schema_migrations" (version) VALUES (20240723122118);
 INSERT INTO public."schema_migrations" (version) VALUES (20240725122924);
 INSERT INTO public."schema_migrations" (version) VALUES (20240805115620);
+INSERT INTO public."schema_migrations" (version) VALUES (20240809122904);
diff --git a/test/sanbase_web/graphql/projects/project_hidden_api_test.exs b/test/sanbase_web/graphql/projects/project_hidden_api_test.exs
new file mode 100644
index 0000000000..5fb4f0aeb5
--- /dev/null
+++ b/test/sanbase_web/graphql/projects/project_hidden_api_test.exs
@@ -0,0 +1,119 @@
+defmodule SanbaseWeb.Graphql.ProjectHiddenApiTest do
+  use SanbaseWeb.ConnCase, async: false
+
+  import Sanbase.Factory
+  import SanbaseWeb.Graphql.TestHelpers
+
+  test "all projects", %{conn: conn} do
+    p1 = insert(:random_erc20_project)
+    p2 = insert(:random_erc20_project)
+    p3 = insert(:random_erc20_project, is_hidden: true)
+
+    # Without includeHidden flag.
+    projects = all_projects(conn)
+    assert length(projects) == 2
+
+    slugs = projects |> Enum.map(& &1["slug"])
+
+    assert p1.slug in slugs
+    assert p2.slug in slugs
+    refute p3.slug in slugs
+
+    # With includeHidden: true flag
+    projects = all_projects_including_hidden(conn)
+    assert length(projects) == 3
+
+    slugs = projects |> Enum.map(& &1["slug"])
+    assert p1.slug in slugs
+    assert p2.slug in slugs
+    assert p3.slug in slugs
+  end
+
+  test "project by slug", %{conn: conn} do
+    p1 = insert(:random_erc20_project)
+    p2 = insert(:random_erc20_project)
+
+    assert {:ok, _} =
+             Sanbase.Project.changeset(p2, %{is_hidden: true, hidden_reason: "duplicate"})
+             |> Sanbase.Repo.update()
+
+    # not a hidden project
+    project = project_by_slug(conn, %{slug: p1.slug})
+
+    assert project == %{
+             "hiddenReason" => nil,
+             "hiddenSince" => nil,
+             "isHidden" => false,
+             "slug" => p1.slug
+           }
+
+    # hidden project
+    project = project_by_slug(conn, %{slug: p2.slug})
+
+    assert %{
+             "hiddenReason" => "duplicate",
+             "hiddenSince" => dt,
+             "isHidden" => true,
+             "slug" => slug
+           } = project
+
+    assert slug == p2.slug
+
+    assert Sanbase.TestUtils.datetime_close_to(
+             DateTime.utc_now(),
+             Sanbase.DateTimeUtils.from_iso8601!(dt),
+             1,
+             :seconds
+           )
+  end
+
+  defp project_by_slug(conn, args) do
+    query = """
+    {
+      projectBySlug(#{map_to_args(args)}){
+        slug
+        isHidden
+        hiddenSince
+        hiddenReason
+      }
+    }
+    """
+
+    conn
+    |> post("/graphql", query_skeleton(query))
+    |> json_response(200)
+    |> get_in(["data", "projectBySlug"])
+  end
+
+  defp all_projects(conn) do
+    query = """
+    {
+      allProjects{
+        slug
+        isHidden
+      }
+    }
+    """
+
+    conn
+    |> post("/graphql", query_skeleton(query))
+    |> json_response(200)
+    |> get_in(["data", "allProjects"])
+  end
+
+  defp all_projects_including_hidden(conn) do
+    query = """
+    {
+      allProjects(includeHidden: true){
+        slug
+        isHidden
+      }
+    }
+    """
+
+    conn
+    |> post("/graphql", query_skeleton(query))
+    |> json_response(200)
+    |> get_in(["data", "allProjects"])
+  end
+end