diff --git a/lib/pleroma/upload.ex b/lib/pleroma/upload.ex
index 4aee9326f3..d36e5de445 100644
--- a/lib/pleroma/upload.ex
+++ b/lib/pleroma/upload.ex
@@ -174,7 +174,7 @@ defp prepare_upload(%Plug.Upload{} = file, opts) do
   defp prepare_upload(%{img: "data:image/" <> image_data}, opts) do
     parsed = Regex.named_captures(~r/(?<filetype>jpeg|png|gif);base64,(?<data>.*)/, image_data)
     data = Base.decode64!(parsed["data"], ignore: :whitespace)
-    hash = Base.encode16(:crypto.hash(:sha256, data), lower: true)
+    hash = Base.encode16(:crypto.hash(:sha256, data), case: :lower)
 
     with :ok <- check_binary_size(data, opts.size_limit),
          tmp_path <- tempfile_for_image(data),
diff --git a/lib/pleroma/web/api_spec/operations/instance_operation.ex b/lib/pleroma/web/api_spec/operations/instance_operation.ex
index 85a1cc7c6b..b26c5a7adc 100644
--- a/lib/pleroma/web/api_spec/operations/instance_operation.ex
+++ b/lib/pleroma/web/api_spec/operations/instance_operation.ex
@@ -57,6 +57,22 @@ def rules_operation do
     }
   end
 
+  def domain_blocks_operation do
+    %Operation{
+      tags: ["Instance"],
+      summary: "Retrieve instance domain blocks",
+      operationId: "InstanceController.domain_blocks",
+      responses: %{
+        200 =>
+          Operation.response(
+            "Array of domain blocks",
+            "application/json",
+            array_of_domain_blocks()
+          )
+      }
+    }
+  end
+
   defp instance do
     %Schema{
       type: :object,
@@ -425,4 +441,19 @@ defp array_of_rules do
       }
     }
   end
+
+  defp array_of_domain_blocks do
+    %Schema{
+      type: :array,
+      items: %Schema{
+        type: :object,
+        properties: %{
+          domain: %Schema{type: :string},
+          digest: %Schema{type: :string},
+          severity: %Schema{type: :string},
+          comment: %Schema{type: :string}
+        }
+      }
+    }
+  end
 end
diff --git a/lib/pleroma/web/mastodon_api/controllers/instance_controller.ex b/lib/pleroma/web/mastodon_api/controllers/instance_controller.ex
index 10293c990e..1e1e350c7a 100644
--- a/lib/pleroma/web/mastodon_api/controllers/instance_controller.ex
+++ b/lib/pleroma/web/mastodon_api/controllers/instance_controller.ex
@@ -30,4 +30,9 @@ def peers(conn, _params) do
   def rules(conn, _params) do
     render(conn, "rules.json")
   end
+
+  @doc "GET /api/v1/instance/domain_blocks"
+  def domain_blocks(conn, _params) do
+    render(conn, "domain_blocks.json")
+  end
 end
diff --git a/lib/pleroma/web/mastodon_api/views/instance_view.ex b/lib/pleroma/web/mastodon_api/views/instance_view.ex
index 3f8d82231e..a2b136a422 100644
--- a/lib/pleroma/web/mastodon_api/views/instance_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/instance_view.ex
@@ -12,6 +12,11 @@ defmodule Pleroma.Web.MastodonAPI.InstanceView do
 
   @mastodon_api_level "2.7.2"
 
+  @block_severities %{
+    federated_timeline_removal: "silence",
+    reject: "suspend"
+  }
+
   def render("show.json", _) do
     instance = Config.get(:instance)
 
@@ -100,6 +105,34 @@ def render("rule.json", %{rule: rule}) do
     }
   end
 
+  def render("domain_blocks.json", _) do
+    if Config.get([:mrf, :transparency]) do
+      exclusions = Config.get([:mrf, :transparency_exclusions]) |> MRF.instance_list_from_tuples()
+
+      domain_blocks =
+        Config.get(:mrf_simple)
+        |> Enum.map(fn {rule, instances} ->
+          MRF.normalize_instance_list(instances)
+          |> Enum.reject(fn {host, _} ->
+            host in exclusions or not Map.has_key?(@block_severities, rule)
+          end)
+          |> Enum.map(fn {host, reason} ->
+            %{
+              domain: host,
+              digest: :crypto.hash(:sha256, host) |> Base.encode16(case: :lower),
+              severity: Map.get(@block_severities, rule),
+              comment: reason
+            }
+          end)
+        end)
+        |> List.flatten()
+
+      domain_blocks
+    else
+      []
+    end
+  end
+
   def features do
     [
       "pleroma_api",
@@ -172,7 +205,7 @@ def federation do
     |> Map.put(:enabled, Config.get([:instance, :federating]))
   end
 
-  def fields_limits do
+  defp fields_limits do
     %{
       max_fields: Config.get([:instance, :max_account_fields]),
       max_remote_fields: Config.get([:instance, :max_remote_account_fields]),
@@ -181,7 +214,7 @@ def fields_limits do
     }
   end
 
-  def configuration do
+  defp configuration do
     %{
       statuses: %{
         max_characters: Config.get([:instance, :limit]),
@@ -200,7 +233,7 @@ def configuration do
     }
   end
 
-  def configuration2 do
+  defp configuration2 do
     configuration()
     |> Map.merge(%{
       urls: %{streaming: Pleroma.Web.Endpoint.websocket_url()},
diff --git a/lib/pleroma/web/router.ex b/lib/pleroma/web/router.ex
index ba6642d4b0..a07ba912f8 100644
--- a/lib/pleroma/web/router.ex
+++ b/lib/pleroma/web/router.ex
@@ -661,6 +661,7 @@ defmodule Pleroma.Web.Router do
     get("/instance", InstanceController, :show)
     get("/instance/peers", InstanceController, :peers)
     get("/instance/rules", InstanceController, :rules)
+    get("/instance/domain_blocks", InstanceController, :domain_blocks)
 
     get("/statuses", StatusController, :index)
     get("/statuses/:id", StatusController, :show)
diff --git a/lib/pleroma/webhook.ex b/lib/pleroma/webhook.ex
index 6cf47fd687..5579b24118 100644
--- a/lib/pleroma/webhook.ex
+++ b/lib/pleroma/webhook.ex
@@ -94,7 +94,6 @@ defp put_secret(changeset) do
   end
 
   defp generate_secret do
-    Base.encode16(:crypto.strong_rand_bytes(20))
-    |> String.downcase()
+    Base.encode16(:crypto.strong_rand_bytes(20), case: :lower)
   end
 end
diff --git a/lib/pleroma/webhook/notify.ex b/lib/pleroma/webhook/notify.ex
index ec84b89ef5..e805dee8f7 100644
--- a/lib/pleroma/webhook/notify.ex
+++ b/lib/pleroma/webhook/notify.ex
@@ -67,6 +67,6 @@ defp deliver(%Webhook{url: url, secret: secret}, object, type) do
   end
 
   defp signature(body, secret) do
-    :crypto.mac(:hmac, :sha256, secret, body) |> Base.encode16()
+    :crypto.mac(:hmac, :sha256, secret, body) |> Base.encode16(case: :lower)
   end
 end
diff --git a/test/pleroma/web/mastodon_api/controllers/instance_controller_test.exs b/test/pleroma/web/mastodon_api/controllers/instance_controller_test.exs
index 6abd021fee..0697820c3d 100644
--- a/test/pleroma/web/mastodon_api/controllers/instance_controller_test.exs
+++ b/test/pleroma/web/mastodon_api/controllers/instance_controller_test.exs
@@ -154,4 +154,31 @@ test "get instance information v2", %{conn: conn} do
     assert get(conn, "/api/v2/instance")
            |> json_response_and_validate_schema(200)
   end
+
+  describe "instance domain blocks" do
+    setup do
+      clear_config([:mrf_simple, :reject], [{"fediverse.pl", "uses Soapbox"}])
+    end
+
+    test "get instance domain blocks", %{conn: conn} do
+      conn = get(conn, "/api/v1/instance/domain_blocks")
+
+      assert [
+               %{
+                 "comment" => "uses Soapbox",
+                 "digest" => "55e3f44aefe7eb022d3b1daaf7396cabf7f181bf6093c8ea841e30c9fc7d8226",
+                 "domain" => "fediverse.pl",
+                 "severity" => "suspend"
+               }
+             ] == json_response_and_validate_schema(conn, 200)
+    end
+
+    test "returns empty array if mrf transparency is disabled", %{conn: conn} do
+      clear_config([:mrf, :transparency], false)
+
+      conn = get(conn, "/api/v1/instance/domain_blocks")
+
+      assert [] == json_response_and_validate_schema(conn, 200)
+    end
+  end
 end