diff --git a/.formatter.exs b/.formatter.exs
new file mode 100644
index 0000000..d2cda26
--- /dev/null
+++ b/.formatter.exs
@@ -0,0 +1,4 @@
+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..6bd0e9a
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,100 @@
+name: Elixir Testing
+
+# Define workflow that runs when changes are pushed to the
+# `main` branch or pushed to a PR branch that targets the `main`
+# branch. Change the branch name if your project uses a
+# different name for the main branch like "master" or "production".
+on:
+  pull_request:
+    branches:
+      - main
+
+permissions:
+  contents: read
+  checks: write
+
+jobs:
+  test:
+    # Sets the ENV `MIX_ENV` to `test` for running tests
+    env:
+      MIX_ENV: test
+      RAILS_ENV: test
+
+    runs-on: ubuntu-22.04
+    name: Test on OTP ${{matrix.otp}} / Elixir ${{matrix.elixir}}
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Detect system info
+      uses: kenchan0130/actions-system-info@master
+      id: system-info
+
+    - name: Setup OTP/Elixir
+      uses: erlef/setup-beam@v1
+      id: setup-beam
+      with:
+        version-type: strict
+        version-file: .tool-versions
+
+    - name: Cache Elixir deps and build
+      uses: actions/cache@v4
+      with:
+        path: |
+          deps
+          _build
+        key: "mix-cache-\
+              ${{ steps.system-info.outputs.name }}-\
+              ${{ steps.system-info.outputs.release }}-\
+              ${{ steps.setup-beam.outputs.otp-version }}-\
+              elixir-${{ steps.setup-beam.outputs.elixir-version }}-\
+              mix.lock-${{ hashFiles('**/mix.lock') }}"
+
+    - name: Install Elixir dependencies
+      run: mix deps.get
+
+    - name: Compiles
+      run: mix compile
+
+    - name: Audit Deprecated dependencies
+      run: mix hex.audit
+
+    - name: Audit Elixir dependencies
+      run: mix deps.audit
+
+    - name: Check Formatting
+      run: |
+        mix format --check-formatted
+
+    - name: Analyze code with credo
+      run: mix credo
+
+    - name: Security check with Sobelow
+      run: mix sobelow --config
+
+    - name: Run tests
+      id: test_with_cover
+      run: |
+        mix test --cover 2>&1 | tee test.log
+        result_code=${PIPESTATUS[0]}
+        echo "coverage=$(cat test.log | grep '\[TOTAL\][[:space:]]\+[^%]\+' | sed 's/[^0-9\.]*//g')" >> "${GITHUB_OUTPUT}"
+        exit $result_code
+
+    # Create the directory where badges will be saved, if needed
+    - name: Create destination directory
+      run: mkdir -p doc
+
+    - name: Create or update coverage ishields json
+      run: |
+        result=${{ steps.test_with_cover.outputs.coverage }}
+        if [ "${result%.*}" -lt 90 ]; then color="orange"; else color="green"; fi
+        echo '{"schemaVersion": 1, "label": "Test coverage", "message": "'"${{ steps.test_with_cover.outputs.coverage }}"'%", "color": "'"${color}"'"}' > doc/coverage.json
+
+    - name: Archive code coverage results
+      uses: actions/upload-artifact@v4
+      with:
+        name: pr-${{ env.PR_NUMBER }}
+        path: doc
+      env:
+        PR_NUMBER: ${{ github.event.number }}
diff --git a/coveralls.json b/coveralls.json
new file mode 100644
index 0000000..174750d
--- /dev/null
+++ b/coveralls.json
@@ -0,0 +1,6 @@
+{
+  "skip_files": [
+    "lib/cyphi/(?!client)",
+    "lib/cyphi/client/adapter/req.ex"
+  ]
+}
diff --git a/lib/cyphi/client.ex b/lib/cyphi/client.ex
index 06c19b9..273857d 100644
--- a/lib/cyphi/client.ex
+++ b/lib/cyphi/client.ex
@@ -31,11 +31,11 @@ defmodule Cyphi.Client do
   end
 
   defp valid_url?(url) do
-    case URI.parse(url) do
-      %URI{host: host, path: path} ->
-        path == "localhost" ||
-          (is_binary(host) and byte_size(host) > 0)
-
+    with true <- is_binary(url) and byte_size(url) > 0,
+         %URI{host: host, path: path} <- URI.parse(url) do
+      path == "localhost" ||
+        (is_binary(host) and byte_size(host) > 0)
+    else
       _ ->
         false
     end
diff --git a/lib/cyphi/client/adapter/req.ex b/lib/cyphi/client/adapter/req.ex
index 1cbe419..1907c92 100644
--- a/lib/cyphi/client/adapter/req.ex
+++ b/lib/cyphi/client/adapter/req.ex
@@ -1,4 +1,6 @@
 defmodule Cyphi.HttpAdapter.Req do
+  @moduledoc false
+
   @behaviour Cyphi.HttpAdapter
 
   @impl true
diff --git a/lib/cyphi/client/adapter/test.ex b/lib/cyphi/client/adapter/test.ex
index d6dcd6d..c3d370a 100644
--- a/lib/cyphi/client/adapter/test.ex
+++ b/lib/cyphi/client/adapter/test.ex
@@ -1,12 +1,17 @@
 defmodule Cyphi.HttpAdapter.Test do
+  @moduledoc false
+
   @behaviour Cyphi.HttpAdapter
 
   @impl true
   def send_request(_method, _url, _opts) do
     case Process.get(:http_response) do
-      nil -> raise "Missing http response process"
+      nil ->
+        raise "Missing http response process"
+
       response when is_map(response) ->
         {:ok, struct(Req.Response, response)}
+
       response ->
         response
     end
diff --git a/lib/cyphi/client/http_adapter.ex b/lib/cyphi/client/http_adapter.ex
index f5a8a1a..2b7a4e7 100644
--- a/lib/cyphi/client/http_adapter.ex
+++ b/lib/cyphi/client/http_adapter.ex
@@ -1,4 +1,12 @@
 defmodule Cyphi.HttpAdapter do
+  @moduledoc """
+  Defines the behaviour for HTTP adapters used by `Cyphi.Client`.
+
+  This contract allows the HTTP backend to be swapped or mocked (e.g., using `Req`
+  in production and a mock in tests). Implementing modules must handle the execution
+  of the network request and return a standard `Req.Response` struct or an error tuple.
+  """
+
   @doc "Contract for HTTP request adapters"
   @callback send_request(method :: atom(), url :: String.t(), opts :: keyword()) ::
               {:ok, Req.Response.t()} | {:error, term()}
diff --git a/lib/cyphi/client/request.ex b/lib/cyphi/client/request.ex
index ba3cdd0..4b2e04a 100644
--- a/lib/cyphi/client/request.ex
+++ b/lib/cyphi/client/request.ex
@@ -1,4 +1,13 @@
 defmodule Cyphi.Client.Request do
+  @moduledoc """
+  Prepares and encodes HTTP request options for the `Cyphi.Client`.
+
+  This module transforms high-level request maps into adapter-compatible keywords by:
+  * **Injecting Headers:** Adds default JSON content types, `Accept` headers, and the `x-api-key` for authentication.
+  * **Serializing Bodies:** Encodes payloads to JSON, ensuring maps and keyword lists are normalized into ordered objects.
+  * **Mapping Parameters:** Converts query parameters into the expected adapter format.
+  """
+
   @spec encode(map()) :: keyword()
   def encode(request) do
     Keyword.new()
@@ -56,7 +65,7 @@ defmodule Cyphi.Client.Request do
         Keyword.put(req_opts, :body, encoded)
 
       err ->
-        {:error,  "Invalid request body: #{inspect(err)}"}
+        {:error, "Invalid request body: #{inspect(err)}"}
     end
   end
 
diff --git a/lib/cyphi/client/response.ex b/lib/cyphi/client/response.ex
index 271bf98..0be8b23 100644
--- a/lib/cyphi/client/response.ex
+++ b/lib/cyphi/client/response.ex
@@ -1,5 +1,17 @@
 defmodule Cyphi.Client.Response do
-  @moduledoc false
+  @moduledoc """
+  Handles the decoding and casting of HTTP responses into Elixir structs.
+
+  This module serves as the final step in the request pipeline. It matches the
+  response status code against a provided `response_spec` (generated by the
+  OpenAPI client) to determine how to process the body.
+
+  ### Decoding Strategy
+  * **Structs (200/201):** Validates and casts raw JSON maps into typed Elixir structs using `Cyphi.Client.Caster`.
+  * **Lists:** Automatically handles lists of items by mapping the decoding logic over the collection.
+  * **Raw Bodies (202/204):** Returns the raw body for Accepted or No Content responses where no schema is strictly defined.
+  * **Errors:** Returns generic error tuples for unhandled status codes (e.g., 404, 500).
+  """
 
   alias Cyphi.Client.Caster
 
@@ -41,11 +53,11 @@ defmodule Cyphi.Client.Response do
     attrs =
       module.__fields__(type)
       |> Enum.reduce(%{}, fn {field, field_type}, acc ->
-           key = Atom.to_string(field)
-           value = Map.get(map, key)
+        key = Atom.to_string(field)
+        value = Map.get(map, key)
 
-           Map.put(acc, String.to_existing_atom(key), Caster.cast(value, field_type))
-         end)
+        Map.put(acc, String.to_existing_atom(key), Caster.cast(value, field_type))
+      end)
 
     struct(module, attrs)
   end
diff --git a/lib/cyphi/course.ex b/lib/cyphi/course.ex
index d76377d..92de285 100644
--- a/lib/cyphi/course.ex
+++ b/lib/cyphi/course.ex
@@ -54,6 +54,7 @@ defmodule Cyphi.Course do
           weights: String.t() | nil
         }
 
+  # credo:disable-for-next-line
   defstruct [
     :access_code,
     :allow_reenrollment,
diff --git a/lib/cyphi/course_template.ex b/lib/cyphi/course_template.ex
index f2aad0c..6be5673 100644
--- a/lib/cyphi/course_template.ex
+++ b/lib/cyphi/course_template.ex
@@ -45,6 +45,7 @@ defmodule Cyphi.CourseTemplate do
           weights: String.t() | nil
         }
 
+  # credo:disable-for-next-line
   defstruct [
     :allow_reenrollment,
     :allow_unenrollment,
diff --git a/lib/cyphi/learner.ex b/lib/cyphi/learner.ex
index 611bb1f..1ac2000 100644
--- a/lib/cyphi/learner.ex
+++ b/lib/cyphi/learner.ex
@@ -41,6 +41,7 @@ defmodule Cyphi.Learner do
           user_id: integer
         }
 
+  # credo:disable-for-next-line
   defstruct [
     :completed,
     :completed_at,
diff --git a/lib/cyphi/user.ex b/lib/cyphi/user.ex
index eb92837..2bde3ce 100644
--- a/lib/cyphi/user.ex
+++ b/lib/cyphi/user.ex
@@ -52,6 +52,7 @@ defmodule Cyphi.User do
           zip: String.t() | nil
         }
 
+  # credo:disable-for-next-line
   defstruct [
     :about,
     :added_by_id,
diff --git a/mix.exs b/mix.exs
index f5662a9..e876234 100644
--- a/mix.exs
+++ b/mix.exs
@@ -8,10 +8,23 @@ defmodule Cyphi.MixProject do
       elixir: "~> 1.17",
       elixirc_paths: elixirc_paths(Mix.env()),
       start_permanent: Mix.env() == :prod,
+      test_coverage: [tool: ExCoveralls],
       deps: deps()
     ]
   end
 
+  def cli do
+    [
+      preferred_envs: [
+        coveralls: :test,
+        "coveralls.detail": :test,
+        "coveralls.post": :test,
+        "coveralls.html": :test,
+        "coveralls.cobertura": :test
+      ]
+    ]
+  end
+
   # Run "mix help compile.app" to learn about applications.
   def application do
     [
@@ -26,10 +39,12 @@ defmodule Cyphi.MixProject do
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
+      {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
+      {:excoveralls, "~> 0.18", only: :test},
+      {:mix_audit, "~> 2.1", only: [:dev, :test], runtime: false},
+      {:oapi_generator, "~> 0.4", only: :dev, runtime: false},
       {:req, "~> 0.5"},
-      {:oapi_generator, "~> 0.4", only: :dev, runtime: false}
-      # {:dep_from_hexpm, "~> 0.3.0"},
-      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
+      {:sobelow, "~> 0.13", only: [:dev, :test], runtime: false}
     ]
   end
 end
diff --git a/mix.lock b/mix.lock
index 9a1a923..9eefe64 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,13 +1,19 @@
 %{
+  "bunt": {:hex, :bunt, "1.0.0", "081c2c665f086849e6d57900292b3a161727ab40431219529f13c4ddcf3e7a44", [:mix], [], "hexpm", "dc5f86aa08a5f6fa6b8096f0735c4e76d54ae5c9fa2c143e5a1fc7c1cd9bb6b5"},
+  "credo": {:hex, :credo, "1.7.14", "c7e75216cea8d978ba8c60ed9dede4cc79a1c99a266c34b3600dd2c33b96bc92", [:mix], [{:bunt, "~> 0.2.1 or ~> 1.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2 or ~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "12a97d6bb98c277e4fb1dff45aaf5c137287416009d214fb46e68147bd9e0203"},
+  "excoveralls": {:hex, :excoveralls, "0.18.5", "e229d0a65982613332ec30f07940038fe451a2e5b29bce2a5022165f0c9b157e", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "523fe8a15603f86d64852aab2abe8ddbd78e68579c8525ae765facc5eae01562"},
+  "file_system": {:hex, :file_system, "1.1.1", "31864f4685b0148f25bd3fbef2b1228457c0c89024ad67f7a81a3ffbc0bbad3a", [:mix], [], "hexpm", "7a15ff97dfe526aeefb090a7a9d3d03aa907e100e262a0f8f7746b78f8f87a5d"},
   "finch": {:hex, :finch, "0.20.0", "5330aefb6b010f424dcbbc4615d914e9e3deae40095e73ab0c1bb0968933cadf", [:mix], [{:mime, "~> 1.0 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:mint, "~> 1.6.2 or ~> 1.7", [hex: :mint, repo: "hexpm", optional: false]}, {:nimble_options, "~> 0.4 or ~> 1.0", [hex: :nimble_options, repo: "hexpm", optional: false]}, {:nimble_pool, "~> 1.1", [hex: :nimble_pool, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "2658131a74d051aabfcba936093c903b8e89da9a1b63e430bee62045fa9b2ee2"},
   "hpax": {:hex, :hpax, "1.0.3", "ed67ef51ad4df91e75cc6a1494f851850c0bd98ebc0be6e81b026e765ee535aa", [:mix], [], "hexpm", "8eab6e1cfa8d5918c2ce4ba43588e894af35dbd8e91e6e55c817bca5847df34a"},
   "jason": {:hex, :jason, "1.4.4", "b9226785a9aa77b6857ca22832cffa5d5011a667207eb2a0ad56adb5db443b8a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "c5eb0cab91f094599f94d55bc63409236a8ec69a21a67814529e8d5f6cc90b3b"},
   "mime": {:hex, :mime, "2.0.7", "b8d739037be7cd402aee1ba0306edfdef982687ee7e9859bee6198c1e7e2f128", [:mix], [], "hexpm", "6171188e399ee16023ffc5b76ce445eb6d9672e2e241d2df6050f3c771e80ccd"},
   "mint": {:hex, :mint, "1.7.1", "113fdb2b2f3b59e47c7955971854641c61f378549d73e829e1768de90fc1abf1", [:mix], [{:castore, "~> 0.1.0 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:hpax, "~> 0.1.1 or ~> 0.2.0 or ~> 1.0", [hex: :hpax, repo: "hexpm", optional: false]}], "hexpm", "fceba0a4d0f24301ddee3024ae116df1c3f4bb7a563a731f45fdfeb9d39a231b"},
+  "mix_audit": {:hex, :mix_audit, "2.1.5", "c0f77cee6b4ef9d97e37772359a187a166c7a1e0e08b50edf5bf6959dfe5a016", [:make, :mix], [{:jason, "~> 1.4", [hex: :jason, repo: "hexpm", optional: false]}, {:yaml_elixir, "~> 2.11", [hex: :yaml_elixir, repo: "hexpm", optional: false]}], "hexpm", "87f9298e21da32f697af535475860dc1d3617a010e0b418d2ec6142bc8b42d69"},
   "nimble_options": {:hex, :nimble_options, "1.1.1", "e3a492d54d85fc3fd7c5baf411d9d2852922f66e69476317787a7b2bb000a61b", [:mix], [], "hexpm", "821b2470ca9442c4b6984882fe9bb0389371b8ddec4d45a9504f00a66f650b44"},
   "nimble_pool": {:hex, :nimble_pool, "1.1.0", "bf9c29fbdcba3564a8b800d1eeb5a3c58f36e1e11d7b7fb2e084a643f645f06b", [:mix], [], "hexpm", "af2e4e6b34197db81f7aad230c1118eac993acc0dae6bc83bac0126d4ae0813a"},
   "oapi_generator": {:hex, :oapi_generator, "0.4.0", "6e4bdee4c87549e223a8adb046276aa924e6c76756909978d05ae61305858791", [:mix], [{:yaml_elixir, "~> 2.9", [hex: :yaml_elixir, repo: "hexpm", optional: false]}], "hexpm", "381d8fce6d1dd16a9407b620bdc31f370a9536590a066f3dd47becaec9ce9b3e"},
   "req": {:hex, :req, "0.5.16", "99ba6a36b014458e52a8b9a0543bfa752cb0344b2a9d756651db1281d4ba4450", [:mix], [{:brotli, "~> 0.3.1", [hex: :brotli, repo: "hexpm", optional: true]}, {:ezstd, "~> 1.0", [hex: :ezstd, repo: "hexpm", optional: true]}, {:finch, "~> 0.17", [hex: :finch, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}, {:mime, "~> 2.0.6 or ~> 2.1", [hex: :mime, repo: "hexpm", optional: false]}, {:nimble_csv, "~> 1.0", [hex: :nimble_csv, repo: "hexpm", optional: true]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: true]}], "hexpm", "974a7a27982b9b791df84e8f6687d21483795882a7840e8309abdbe08bb06f09"},
+  "sobelow": {:hex, :sobelow, "0.14.1", "2f81e8632f15574cba2402bcddff5497b413c01e6f094bc0ab94e83c2f74db81", [:mix], [{:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "8fac9a2bd90fdc4b15d6fca6e1608efb7f7c600fa75800813b794ee9364c87f2"},
   "telemetry": {:hex, :telemetry, "1.3.0", "fedebbae410d715cf8e7062c96a1ef32ec22e764197f70cda73d82778d61e7a2", [:rebar3], [], "hexpm", "7015fc8919dbe63764f4b4b87a95b7c0996bd539e0d499be6ec9d7f3875b79e6"},
   "yamerl": {:hex, :yamerl, "0.10.0", "4ff81fee2f1f6a46f1700c0d880b24d193ddb74bd14ef42cb0bcf46e81ef2f8e", [:rebar3], [], "hexpm", "346adb2963f1051dc837a2364e4acf6eb7d80097c0f53cbdc3046ec8ec4b4e6e"},
   "yaml_elixir": {:hex, :yaml_elixir, "2.12.0", "30343ff5018637a64b1b7de1ed2a3ca03bc641410c1f311a4dbdc1ffbbf449c7", [:mix], [{:yamerl, "~> 0.10", [hex: :yamerl, repo: "hexpm", optional: false]}], "hexpm", "ca6bacae7bac917a7155dca0ab6149088aa7bc800c94d0fe18c5238f53b313c6"},
diff --git a/test/cyphi/client/caster_test.exs b/test/cyphi/client/caster_test.exs
index 30cbab8..9f22811 100644
--- a/test/cyphi/client/caster_test.exs
+++ b/test/cyphi/client/caster_test.exs
@@ -41,8 +41,8 @@ defmodule Cyphi.Client.CasterTest do
     end
 
     test "returns nil for invalid date strings (soft failure)" do
-      assert Caster.cast("not a date" , {:string, "date-time"}) == nil
-      assert Caster.cast("00-01-01 10:22:00" , {:string, "date-time"}) == nil
+      assert Caster.cast("not a date", {:string, "date-time"}) == nil
+      assert Caster.cast("00-01-01 10:22:00", {:string, "date-time"}) == nil
     end
   end
 
diff --git a/test/cyphi/client/request_test.exs b/test/cyphi/client/request_test.exs
index 6e5319f..d46daff 100644
--- a/test/cyphi/client/request_test.exs
+++ b/test/cyphi/client/request_test.exs
@@ -94,5 +94,11 @@ defmodule Cyphi.Client.RequestTest do
       assert msg =~ "Invalid request body:"
       assert msg =~ "Jason.Encoder"
     end
+
+    test "normalize simple values body" do
+      request = Request.encode(%{body: 10})
+
+      assert request[:body] == "10"
+    end
   end
 end
diff --git a/test/cyphi/client/response_test.exs b/test/cyphi/client/response_test.exs
index 1361396..5ec1af3 100644
--- a/test/cyphi/client/response_test.exs
+++ b/test/cyphi/client/response_test.exs
@@ -9,8 +9,7 @@ defmodule Cyphi.Client.ResponseTest do
      req_success: %Req.Response{status: 200, body: %{}},
      req_created: %Req.Response{status: 201, body: %{}},
      req_accepted: %Req.Response{status: 202, body: %{}},
-     req_error: %Req.Response{status: 404, body: "Not Found"}
-    }
+     req_error: %Req.Response{status: 404, body: "Not Found"}}
   end
 
   describe "decode/2 with Adapter Error" do
@@ -56,6 +55,7 @@ defmodule Cyphi.Client.ResponseTest do
         %{"first_name" => "A", "id" => 1},
         %{"first_name" => "B", "id" => 2}
       ]
+
       req = %Req.Response{status: 200, body: body}
       opts = %{response: [{200, [{Cyphi.User, :t}]}]}
 
diff --git a/test/cyphi/client_test.exs b/test/cyphi/client_test.exs
index 34454ee..7f95f3e 100644
--- a/test/cyphi/client_test.exs
+++ b/test/cyphi/client_test.exs
@@ -110,5 +110,14 @@ defmodule Cyphi.ClientTest do
         end)
       end)
     end
+
+    test "Invalid nil response" do
+      assert_raise RuntimeError, "Missing http response process", fn ->
+        with_response(nil, fn ->
+          opts = %{method: :get, url: "/", response: []}
+          assert {:ok, _resp} = Client.request(opts)
+        end)
+      end
+    end
   end
 end
diff --git a/test/support/client_api_helper.ex b/test/support/client_api_helper.ex
index 52684fb..7004a28 100644
--- a/test/support/client_api_helper.ex
+++ b/test/support/client_api_helper.ex
@@ -1,4 +1,6 @@
 defmodule Cyphi.ClientApiHelper do
+  @moduledoc false
+
   def with_api_url(url, fun) do
     original_url = Application.get_env(:cyphi, :api_url)
     Application.put_env(:cyphi, :api_url, url)