diff --git a/.github/workflows/phpstan-5.yaml b/.github/workflows/phpstan-5.yaml
deleted file mode 100644
index 2488785..0000000
--- a/.github/workflows/phpstan-5.yaml
+++ /dev/null
@@ -1,24 +0,0 @@
-name: PHPStan level 5
-on: push
-jobs:
-  phpstan:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - uses: actions/cache@v3
-        with:
-          path: '**/vendor'
-          key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-composer-
-      - uses: php-actions/composer@v6
-        with:
-          args: --prefer-dist
-          php_version: '8.2'
-
-      -   name: PHPStan
-          uses: php-actions/phpstan@v3
-          with:
-            path: src/
-            level: 5
-            php_version: '8.2'
diff --git a/.github/workflows/quality.yaml b/.github/workflows/quality.yaml
index c1791da..920b797 100644
--- a/.github/workflows/quality.yaml
+++ b/.github/workflows/quality.yaml
@@ -1,4 +1,4 @@
-name: Quality (PHPStan level 4)
+name: Quality (PHPStan level 5)
 on: push
 jobs:
   cs-fixer:
@@ -34,5 +34,5 @@ jobs:
         uses: php-actions/phpstan@v3
         with:
           path: src/
-          level: 4
+          level: 5
           php_version: '8.2'
diff --git a/composer.json b/composer.json
index 1f04273..37b91e1 100644
--- a/composer.json
+++ b/composer.json
@@ -34,7 +34,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-main": "0.4.x-dev"
+            "dev-main": "0.5.x-dev"
         }
     }
 }
diff --git a/src/ExtractingInterface.php b/src/ExtractingInterface.php
index 8f46007..383e8d2 100644
--- a/src/ExtractingInterface.php
+++ b/src/ExtractingInterface.php
@@ -12,8 +12,9 @@ interface ExtractingInterface
      * @param ExtractorInterface<Type> $extractor
      */
     public function extract(
+        StepCodeInterface $step,
         ExtractorInterface $extractor,
-        RejectionInterface $rejection,
-        StateInterface $state,
+        StepRejectionInterface $rejection,
+        StepStateInterface $state,
     ): self;
 }
diff --git a/src/LoadingInterface.php b/src/LoadingInterface.php
index 3dc720f..073c97b 100644
--- a/src/LoadingInterface.php
+++ b/src/LoadingInterface.php
@@ -12,8 +12,9 @@ interface LoadingInterface
      * @param LoaderInterface<Type> $loader
      */
     public function load(
+        StepCodeInterface $step,
         LoaderInterface $loader,
-        RejectionInterface $rejection,
-        StateInterface $state,
+        StepRejectionInterface $rejection,
+        StepStateInterface $state,
     ): self;
 }
diff --git a/src/NullRejection.php b/src/NullRejection.php
index bd5b239..111700a 100644
--- a/src/NullRejection.php
+++ b/src/NullRejection.php
@@ -11,8 +11,14 @@ public function initialize(): void
         // NOOP
     }
 
-    /** @param non-empty-array<mixed>|object $rejection */
-    public function reject(array|object $rejection, \Throwable $exception = null, string $reason = null): void
+    /** @param non-empty-array<array-key, mixed>|object $rejection */
+    public function reject(StepCodeInterface $step, array|object $rejection, \Throwable $exception = null, string $reason = null): void
+    {
+        // NOOP
+    }
+
+    /** @param non-empty-array<array-key, mixed>|object $rejection */
+    public function rejectWithReason(StepCodeInterface $step, array|object $rejection, string $reason, \Throwable $exception = null): void
     {
         // NOOP
     }
diff --git a/src/NullState.php b/src/NullState.php
index 437b6f9..c9b0970 100644
--- a/src/NullState.php
+++ b/src/NullState.php
@@ -11,17 +11,17 @@ public function initialize(int $start = 0): void
         // NOOP
     }
 
-    public function accept(int $step = 1): void
+    public function accept(StepCodeInterface $step, int $count = 1): void
     {
         // NOOP
     }
 
-    public function reject(int $step = 1): void
+    public function reject(StepCodeInterface $step, int $count = 1): void
     {
         // NOOP
     }
 
-    public function error(int $step = 1): void
+    public function error(StepCodeInterface $step, int $count = 1): void
     {
         // NOOP
     }
diff --git a/src/PipelineRunnerInterface.php b/src/PipelineRunnerInterface.php
index 83618e9..b652778 100644
--- a/src/PipelineRunnerInterface.php
+++ b/src/PipelineRunnerInterface.php
@@ -12,7 +12,7 @@
 interface PipelineRunnerInterface
 {
     /**
-     * @param \Iterator<array|object>                                    $source
+     * @param \Iterator<int, array|object>                               $source
      * @param \Generator<mixed, Type, ResultBucketInterface<Type>, void> $async
      *
      * @return \Iterator<array|object>
diff --git a/src/RejectionInterface.php b/src/RejectionInterface.php
index a11fdab..eaa3409 100644
--- a/src/RejectionInterface.php
+++ b/src/RejectionInterface.php
@@ -8,8 +8,11 @@ interface RejectionInterface
 {
     public function initialize(): void;
 
-    /** @param non-empty-array<mixed>|object $rejection */
-    public function reject(array|object $rejection, \Throwable $exception = null, string $reason = null): void;
+    /** @param non-empty-array<array-key, mixed>|object $rejection */
+    public function reject(StepCodeInterface $step, array|object $rejection, \Throwable $exception = null): void;
+
+    /** @param non-empty-array<array-key, mixed>|object $rejection */
+    public function rejectWithReason(StepCodeInterface $step, array|object $rejection, string $reason, \Throwable $exception = null): void;
 
     public function teardown(): void;
 }
diff --git a/src/RejectionWithReasonInterface.php b/src/RejectionWithReasonInterface.php
deleted file mode 100644
index a8aedf7..0000000
--- a/src/RejectionWithReasonInterface.php
+++ /dev/null
@@ -1,10 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Kiboko\Contract\Pipeline;
-
-interface RejectionWithReasonInterface extends RejectionInterface
-{
-    public function rejectWithReason(object|array $rejection, string $reason, null|\Throwable $exception = null): void;
-}
diff --git a/src/StateInterface.php b/src/StateInterface.php
index 9d7b5aa..a8f0551 100644
--- a/src/StateInterface.php
+++ b/src/StateInterface.php
@@ -8,11 +8,11 @@ interface StateInterface
 {
     public function initialize(int $start = 0): void;
 
-    public function accept(int $step = 1): void;
+    public function accept(StepCodeInterface $step, int $count = 1): void;
 
-    public function reject(int $step = 1): void;
+    public function reject(StepCodeInterface $step, int $count = 1): void;
 
-    public function error(int $step = 1): void;
+    public function error(StepCodeInterface $step, int $count = 1): void;
 
     public function teardown(): void;
 }
diff --git a/src/StepCodeInterface.php b/src/StepCodeInterface.php
new file mode 100644
index 0000000..a5c48b0
--- /dev/null
+++ b/src/StepCodeInterface.php
@@ -0,0 +1,7 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kiboko\Contract\Pipeline;
+
+interface StepCodeInterface extends \Stringable {}
diff --git a/src/StepRejectionInterface.php b/src/StepRejectionInterface.php
new file mode 100644
index 0000000..bc58834
--- /dev/null
+++ b/src/StepRejectionInterface.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kiboko\Contract\Pipeline;
+
+interface StepRejectionInterface
+{
+    public function initialize(): void;
+
+    /** @param non-empty-array<mixed>|object $rejection */
+    public function reject(array|object $rejection, \Throwable $exception = null): void;
+
+    public function rejectWithReason(array|object $rejection, string $reason, \Throwable $exception = null): void;
+
+    public function teardown(): void;
+}
diff --git a/src/StepStateInterface.php b/src/StepStateInterface.php
new file mode 100644
index 0000000..00f42b1
--- /dev/null
+++ b/src/StepStateInterface.php
@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Kiboko\Contract\Pipeline;
+
+interface StepStateInterface
+{
+    public function accept(StepCodeInterface $step, int $count = 1): void;
+
+    public function reject(StepCodeInterface $step, int $count = 1): void;
+
+    public function error(StepCodeInterface $step, int $count = 1): void;
+}
diff --git a/src/TransformingInterface.php b/src/TransformingInterface.php
index 55a2ee5..c381f3b 100644
--- a/src/TransformingInterface.php
+++ b/src/TransformingInterface.php
@@ -12,8 +12,9 @@ interface TransformingInterface
      * @param TransformerInterface<Type> $transformer
      */
     public function transform(
+        StepCodeInterface $step,
         TransformerInterface $transformer,
-        RejectionInterface $rejection,
-        StateInterface $state,
+        StepRejectionInterface $rejection,
+        StepStateInterface $state,
     ): self;
 }