diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
new file mode 100644
index 00000000..455d0d32
--- /dev/null
+++ b/.github/workflows/CI.yml
@@ -0,0 +1,39 @@
+name: CI
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  CI:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        toolchain: ['stable', 'nightly']
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install task command
+        run:  sh -c "$(curl --location https://taskfile.dev/install.sh)" -- -d -b /usr/local/bin
+
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.toolchain }}
+          profile:   minimal
+          override:  true
+
+      - name: Cache cargo tools
+        id:   cache_cargo_tools
+        uses: actions/cache@v3
+        with:
+          key:  ${{ runner.os }}-cargo-install
+          path: ~/.cargo/bin
+      - name: Install cargo tools
+        if:   ${{ steps.cache_cargo_tools.outputs.cache-hit != 'true' }}
+        run:  cargo install sqlx-cli --no-default-features --features native-tls,postgres
+      
+      - name: Run tasks
+        run:  task test check ${{ matrix.toolchain == 'nightly' && 'bench' || '' }}
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
deleted file mode 100644
index 3318f107..00000000
--- a/.github/workflows/check.yml
+++ /dev/null
@@ -1,54 +0,0 @@
-name: check
-on:
-  pull_request:
-  push:
-    branches:
-      - main
-
-jobs:
-  Check:
-    runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        rt:            ['tokio', 'async-std']
-        toolchain:     ['stable', 'nightly']
-        custom-header: [true, false]
-
-    steps:
-      - uses: actions/checkout@v4
-
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: ${{ matrix.toolchain }}
-          profile:   minimal
-          override:  true
-
-      - name: Check ohkami's buildability
-        run:  cargo check --features rt_${{ matrix.rt }}${{ matrix.custom-header && ',custom-header' || '' }}
-        
-      - name: Check ohkami's buildability without default features except fot `utils`
-        run:  cargo check --no-default-features --features utils,rt_${{ matrix.rt }}${{ matrix.custom-header && ',custom-header' || '' }}
-      
-      - name: Check ohkami's buildability without default features except fot `testing`
-        run:  cargo check --no-default-features --features testing,rt_${{ matrix.rt }}${{ matrix.custom-header && ',custom-header' || '' }}
-      
-      - name: Check ohkami's buildability without default features
-        run:  cargo check --no-default-features --features rt_${{ matrix.rt }}${{ matrix.custom-header && ',custom-header' || '' }}
-      
-      - name: Cache cargo tools
-        id:   cache_cargo_tools
-        uses: actions/cache@v3
-        with:
-          key:  ${{ runner.os }}-cargo-install
-          path: ~/.cargo/bin
-      - name: Install cargo tools
-        if:   ${{ steps.cache_cargo_tools.outputs.cache-hit != 'true' }}
-        run:  |
-          cargo install sqlx-cli --no-default-features --features native-tls,postgres
-      - name: Check examples' buildablity
-        working-directory: examples
-        run: |
-          docker-compose -f ./realworld/docker-compose.yml up -d
-          cd ./realworld && sqlx migrate run
-          cargo check
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
deleted file mode 100644
index f8084f60..00000000
--- a/.github/workflows/test.yml
+++ /dev/null
@@ -1,63 +0,0 @@
-name: test
-on:
-  pull_request:
-  push:
-    branches:
-      - main
-
-jobs:
-  Test:
-    runs-on: ubuntu-latest
-
-    strategy:
-      matrix:
-        rt:            ['tokio', 'async-std']
-        toolchain:     ['stable', 'nightly']
-        custom-header: [true, false]
-
-    steps:
-      - uses: actions/checkout@v4
-
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: ${{ matrix.toolchain }}
-          profile:   minimal
-          override:  true
-
-      - name: Run ohkami's doc tests
-        if:   matrix.rt == 'tokio'
-        run:  cargo test --doc --features rt_${{ matrix.rt }},DEBUG${{ matrix.custom-header && ',custom-header' || '' }}
-
-      - name: Run ohkami's lib tests
-        run:  cargo test --lib --features rt_${{ matrix.rt }},DEBUG${{ matrix.custom-header && ',custom-header' || '' }}
-
-      - name: Run ohkami's lib tests without default features except fot `utils`
-        run:  cargo test --lib --no-default-features --features utils,rt_${{ matrix.rt }},DEBUG${{ matrix.custom-header && ',custom-header' || '' }}
-      
-      - name: Run ohkami's lib tests without default features except fot `testing`
-        run:  cargo test --lib --no-default-features --features testing,rt_${{ matrix.rt }},DEBUG${{ matrix.custom-header && ',custom-header' || '' }}
-      
-      - name: Run ohkami's lib tests without default features
-        run:  cargo test --lib --no-default-features --features rt_${{ matrix.rt }},DEBUG${{ matrix.custom-header && ',custom-header' || '' }}
-
-      - name: Run ohkami's benchmark
-        if:   matrix.toolchain == 'nightly'
-        working-directory: benches
-        run:  cargo bench
-      
-      - name: Cache cargo tools
-        id:   cache_cargo_tools
-        uses: actions/cache@v3
-        with:
-          key:  ${{ runner.os }}-cargo-install
-          path: ~/.cargo/bin
-      - name: Install cargo tools
-        if:   ${{ steps.cache_cargo_tools.outputs.cache-hit != 'true' }}
-        run:  |
-          cargo install sqlx-cli --no-default-features --features native-tls,postgres
-      - name: Run tests of examples
-        working-directory: examples
-        run: |
-          docker-compose -f ./realworld/docker-compose.yml up -d
-          cd ./realworld && sqlx migrate run
-          cargo test 
diff --git a/README.md b/README.md
index 91c8f72c..38bd0835 100644
--- a/README.md
+++ b/README.md
@@ -9,8 +9,7 @@
 - *multi runtime* support：`tokio`, `async-std`
 
 <div align="right">
-    <img alt="build check status of ohkami" src="https://github.com/kana-rus/ohkami/actions/workflows/check.yml/badge.svg"/>
-    <img alt="test status of ohkami" src="https://github.com/kana-rus/ohkami/actions/workflows/test.yml/badge.svg"/>
+    <img alt="build check status of ohkami" src="https://github.com/kana-rus/ohkami/actions/workflows/CI.yml/badge.svg"/>
 </div>
 
 <br>
@@ -243,7 +242,5 @@ async fn test_my_ohkami() {
 ## MSRV (Minimum Supported Rust Version)
 Latest stable.
 
-<br>
-
 ## License
 `ohkami` is licensed under MIT LICENSE ([LICENSE-MIT](https://github.com/kana-rus/ohkami/blob/main/LICENSE-MIT) or [https://opensource.org/licenses/MIT](https://opensource.org/licenses/MIT)).
diff --git a/Taskfile.yaml b/Taskfile.yaml
index 3fae42e0..7979e7b6 100644
--- a/Taskfile.yaml
+++ b/Taskfile.yaml
@@ -1,23 +1,93 @@
 version: '3'
 
 tasks:
-  test_rt_async-std:
+  test:
+    deps:
+      - test_doc
+      - test_rt_tokio
+      - test_rt_tokio_with_custom-header
+      - test_rt_async-std
+      - test_rt_async-std_with_custom-header
+      - test_examples
+
+  check:
+    deps:
+      - check_rt_tokio
+      - check_rt_async-std
+
+  bench:
+    dir: benches
+    cmds:
+      - cargo bench
+
+#### tests ####
+  test_doc:
+    dir: ohkami
     cmds:
-      - cargo test --no-default-features --features rt_tokio
-      - cargo test --no-default-features --features rt_tokio,utils
-      - cargo test --no-default-features --features rt_tokio,testing
-      - cargo test --no-default-features --features rt_tokio,utils,testing
-      - cargo test --no-default-features --features custom-header,rt_tokio
-      - cargo test --no-default-features --features custom-header,rt_tokio,utils
-      - cargo test --no-default-features --features custom-header,rt_tokio,testing
-      - cargo test --no-default-features --features custom-header,rt_tokio,utils,testing
+      - cargo test --doc --features DEBUG,rt_tokio
+      - cargo test --doc --features DEBUG,rt_tokio,custom-header
+
+  test_rt_tokio:
+    dir: ohkami
+    cmds:
+      - cargo test --lib --no-default-features --features DEBUG,rt_tokio
+      - cargo test --lib --no-default-features --features DEBUG,rt_tokio,utils
+      - cargo test --lib --no-default-features --features DEBUG,rt_tokio,testing
+      - cargo test --lib --no-default-features --features DEBUG,rt_tokio,utils,testing
+  test_rt_tokio_with_custom-header:
+    dir: ohkami
+    cmds:
+      - cargo test --lib --no-default-features --features DEBUG,custom-header,rt_tokio
+      - cargo test --lib --no-default-features --features DEBUG,custom-header,rt_tokio,utils
+      - cargo test --lib --no-default-features --features DEBUG,custom-header,rt_tokio,testing
+      - cargo test --lib --no-default-features --features DEBUG,custom-header,rt_tokio,utils,testing
+
   test_rt_async-std:
+    dir: ohkami
+    cmds:
+      - cargo test --lib --no-default-features --features DEBUG,rt_async-std
+      - cargo test --lib --no-default-features --features DEBUG,rt_async-std,utils
+      - cargo test --lib --no-default-features --features DEBUG,rt_async-std,testing
+      - cargo test --lib --no-default-features --features DEBUG,rt_async-std,utils,testing
+  test_rt_async-std_with_custom-header:
+    dir: ohkami
+    cmds:
+      - cargo test --lib --no-default-features --features DEBUG,custom-header,rt_async-std
+      - cargo test --lib --no-default-features --features DEBUG,custom-header,rt_async-std,utils
+      - cargo test --lib --no-default-features --features DEBUG,custom-header,rt_async-std,testing
+      - cargo test --lib --no-default-features --features DEBUG,custom-header,rt_async-std,utils,testing
+
+  test_examples:
+    dir: examples
+    cmds:
+      - docker compose -f ./realworld/docker-compose.yml up -d
+      - cd ./realworld && sleep 5 && sqlx migrate run
+      - cargo test
+      - docker compose -f ./realworld/docker-compose.yml down
+
+#### checks ####
+  # Assure buildability without "DEBUG" feature
+
+  check_rt_tokio:
+    dir: ohkami
+    cmds:
+      - cargo check --lib --no-default-features --features rt_tokio
+      - cargo check --lib --no-default-features --features rt_tokio,utils
+      - cargo check --lib --no-default-features --features rt_tokio,testing
+      - cargo check --lib --no-default-features --features rt_tokio,utils,testing
+      - cargo check --lib --no-default-features --features custom-header,rt_tokio
+      - cargo check --lib --no-default-features --features custom-header,rt_tokio,utils
+      - cargo check --lib --no-default-features --features custom-header,rt_tokio,testing
+      - cargo check --lib --no-default-features --features custom-header,rt_tokio,utils,testing
+
+  check_rt_async-std:
+    dir: ohkami
     cmds:
-      - cargo test --no-default-features --features rt_async-std
-      - cargo test --no-default-features --features rt_async-std,utils
-      - cargo test --no-default-features --features rt_async-std,testing
-      - cargo test --no-default-features --features rt_async-std,utils,testing
-      - cargo test --no-default-features --features custom-header,rt_async-std
-      - cargo test --no-default-features --features custom-header,rt_async-std,utils
-      - cargo test --no-default-features --features custom-header,rt_async-std,testing
-      - cargo test --no-default-features --features custom-header,rt_async-std,utils,testing
\ No newline at end of file
+      - cargo check --lib --no-default-features --features rt_async-std
+      - cargo check --lib --no-default-features --features rt_async-std,utils
+      - cargo check --lib --no-default-features --features rt_async-std,testing
+      - cargo check --lib --no-default-features --features rt_async-std,utils,testing
+      - cargo check --lib --no-default-features --features custom-header,rt_async-std
+      - cargo check --lib --no-default-features --features custom-header,rt_async-std,utils
+      - cargo check --lib --no-default-features --features custom-header,rt_async-std,testing
+      - cargo check --lib --no-default-features --features custom-header,rt_async-std,utils,testing
diff --git a/ohkami/Cargo.toml b/ohkami/Cargo.toml
index 0bfca8ef..bca85933 100644
--- a/ohkami/Cargo.toml
+++ b/ohkami/Cargo.toml
@@ -21,7 +21,7 @@ ohkami_macros = { version = "=0.5.1", path = "../ohkami_macros" }
 tokio         = { version = "1", optional = true, features = ["net", "rt", "io-util", "sync"] }
 async-std     = { version = "1", optional = true }
 byte_reader   = { version = "2.0.0", features = ["text"] }
-serde         = "1.0"
+serde         = { version = "1.0",   features = ["derive"] }
 serde_json    = "1.0"
 sha1          = { version = "=0.11.0-pre.0", optional = true, default-features = false }
 sha2          = { version = "=0.11.0-pre.0", default-features = false }
@@ -40,7 +40,6 @@ custom-header = ["dep:rustc-hash"]
 
 ##### DEBUG #####
 DEBUG = [
-    "serde/derive",
     "tokio?/macros",
     "tokio?/rt-multi-thread",
     "async-std?/attributes",
diff --git a/ohkami/src/response/mod.rs b/ohkami/src/response/mod.rs
index 674a4c3e..5080ca92 100644
--- a/ohkami/src/response/mod.rs
+++ b/ohkami/src/response/mod.rs
@@ -2,7 +2,9 @@ mod status;
 pub use status::Status;
 
 mod headers;
-pub use headers::{Headers as ResponseHeaders, Header as ResponseHeader};
+pub use headers::{Headers as ResponseHeaders};
+#[cfg(any(feature="testing", feature="DEBUG"))]
+pub use headers::Header as ResponseHeader;
 
 mod into_response;
 pub use into_response::IntoResponse;