diff --git a/.env.dev b/.env.dev
index 2b1dd6d..a833016 100644
--- a/.env.dev
+++ b/.env.dev
@@ -1,2 +1,3 @@
+export SUPABASE_LOCAL=1
 export SUPABASE_URL=http://127.0.0.1:54321
 export SUPABASE_KEY=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZS1kZW1vIiwicm9sZSI6InNlcnZpY2Vfcm9sZSIsImV4cCI6MTk4MzgxMjk5Nn0.EGIM96RAZx35lJzdJsyH-qQwv8Hdp7fsn3W0YpN81IU
diff --git a/.gitignore b/.gitignore
index 501f9c7..89e949a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,3 +25,5 @@ supabase_functions-*.tar
 /priv/plts/
 
 .env.dev
+/.claude/
+/.expert/
diff --git a/lib/supabase/functions.ex b/lib/supabase/functions.ex
index 0e6584d..e3865b4 100644
--- a/lib/supabase/functions.ex
+++ b/lib/supabase/functions.ex
@@ -77,6 +77,7 @@ defmodule Supabase.Functions do
     |> Request.with_headers(custom_headers)
     |> execute_request(opts[:on_response])
     |> maybe_decode_body()
+    |> handle_response()
   end
 
   defp maybe_define_region(req, nil), do: req
@@ -128,4 +129,20 @@ defmodule Supabase.Functions do
   defp decoder_from_content_type(_) do
     fn body -> {:ok, Function.identity(body)} end
   end
+
+  defp handle_response({:ok, %Response{} = resp}) do
+    if Response.get_header(resp, "x-relay-error") == "true" do
+      {:error,
+       Supabase.Error.new(
+         service: :functions,
+         code: :relay_error,
+         message: "Relay Error invoking the Edge Function",
+         metadata: resp
+       )}
+    else
+      {:ok, resp}
+    end
+  end
+
+  defp handle_response(other), do: other
 end
diff --git a/mix.exs b/mix.exs
index 373f39f..b5835ad 100644
--- a/mix.exs
+++ b/mix.exs
@@ -25,10 +25,18 @@ defmodule Supabase.Functions.MixProject do
     ]
   end
 
+  defp supabase_dep do
+    if System.get_env("SUPABASE_LOCAL") == "1" do
+      {:supabase_potion, path: "../supabase-ex"}
+    else
+      {:supabase_potion, "~> 0.6"}
+    end
+  end
+
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
-      {:supabase_potion, "~> 0.6"},
+      supabase_dep(),
       {:mox, "~> 1.0", only: :test},
       {:ex_doc, ">= 0.0.0", only: [:dev], runtime: false},
       {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
diff --git a/mix.lock b/mix.lock
index 1b7b1f7..4c86239 100644
--- a/mix.lock
+++ b/mix.lock
@@ -4,7 +4,7 @@
   "decimal": {:hex, :decimal, "2.3.0", "3ad6255aa77b4a3c4f818171b12d237500e63525c2fd056699967a3e7ea20f62", [:mix], [], "hexpm", "a4d66355cb29cb47c3cf30e71329e58361cfcb37c34235ef3bf1d7bf3773aeac"},
   "dialyxir": {:hex, :dialyxir, "1.4.5", "ca1571ac18e0f88d4ab245f0b60fa31ff1b12cbae2b11bd25d207f865e8ae78a", [:mix], [{:erlex, ">= 0.2.7", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "b0fb08bb8107c750db5c0b324fa2df5ceaa0f9307690ee3c1f6ba5b9eb5d35c3"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.44", "f20830dd6b5c77afe2b063777ddbbff09f9759396500cdbe7523efd58d7a339c", [:mix], [], "hexpm", "4778ac752b4701a5599215f7030989c989ffdc4f6df457c5f36938cc2d2a2750"},
-  "ecto": {:hex, :ecto, "3.13.2", "7d0c0863f3fc8d71d17fc3ad3b9424beae13f02712ad84191a826c7169484f01", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "669d9291370513ff56e7b7e7081b7af3283d02e046cf3d403053c557894a0b3e"},
+  "ecto": {:hex, :ecto, "3.13.5", "9d4a69700183f33bf97208294768e561f5c7f1ecf417e0fa1006e4a91713a834", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "df9efebf70cf94142739ba357499661ef5dbb559ef902b68ea1f3c1fabce36de"},
   "erlex": {:hex, :erlex, "0.2.7", "810e8725f96ab74d17aac676e748627a07bc87eb950d2b83acd29dc047a30595", [:mix], [], "hexpm", "3ed95f79d1a844c3f6bf0cea61e0d5612a42ce56da9c03f01df538685365efb0"},
   "ex_doc": {:hex, :ex_doc, "0.38.2", "504d25eef296b4dec3b8e33e810bc8b5344d565998cd83914ffe1b8503737c02", [:mix], [{:earmark_parser, "~> 1.4.44", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "732f2d972e42c116a70802f9898c51b54916e542cc50968ac6980512ec90f42b"},
   "file_system": {:hex, :file_system, "1.1.0", "08d232062284546c6c34426997dd7ef6ec9f8bbd090eb91780283c9016840e8f", [:mix], [], "hexpm", "bfcf81244f416871f2a2e15c1b515287faa5db9c6bcf290222206d120b3d43f6"},
diff --git a/test/supabase/functions_test.exs b/test/supabase/functions_test.exs
index 2fbd85c..d32c011 100644
--- a/test/supabase/functions_test.exs
+++ b/test/supabase/functions_test.exs
@@ -172,5 +172,21 @@ defmodule Supabase.FunctionsTest do
 
       assert response.body == %{"success" => true}
     end
+
+    test "handles relay errors", %{client: client} do
+      expect(@mock, :stream, fn _request, _ ->
+        {:ok,
+         %Finch.Response{
+           status: 200,
+           headers: %{"content-type" => "application/json", "x-relay-error" => "true"},
+           body: ~s({"error": "Relay Error"})
+         }}
+      end)
+
+      assert {:error, error} =
+               Functions.invoke(client, "test-function", http_client: @mock)
+
+      assert error.code == :relay_error
+    end
   end
 end