diff --git a/CHANGELOG.md b/CHANGELOG.md
index 032aa9b..8d0badf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+## 0.3.8 - 2024-08-03
+- Implementing the `applyField()` method
+
 ## 0.3.7 - 2024-07-28
 - Implementing the `forEach()` method
 
diff --git a/README.md b/README.md
index 49936d6..e537b75 100644
--- a/README.md
+++ b/README.md
@@ -193,7 +193,17 @@ The `set()` method supports keys with the dot (or custom) notation for setting v
 If a key doesn't exist, the `set()` method creates one and sets the value.
 If a key already exists, the `set()` method will replace the value related to the key.
 
-For example:
+#### Parameters
+
+- `key` (int|string): The key to which the value should be assigned. If a string is provided, you can use dot notation to set nested values.
+- `value` (mixed): The value to be assigned to the specified key.
+- `charNestedKey` (string, optional): The character used for dot notation in nested keys. Defaults to `.`.
+
+#### Returns
+
+- `self`: Returns the instance of the class for method chaining.
+
+#### Example Usage
 
 ```php
 $articleText = "Some words as a sample sentence";
@@ -614,7 +624,7 @@ $posts = Block::fromJsonUrl($url) // Load the Block from the remote URL
 // $posts->get("0.tags"); // 3
 ```
 
-## Validating Data 🆕
+## Validating Data
 
 You can validate the data in the Block object with JSON schema.
 JSON Schema is a vocabulary used to annotate and validate JSON documents.
@@ -723,6 +733,34 @@ $data->validateJsonWithSchema(
 );
 ```
 
+## Applying functions
+
+The `applyField()` method applies a callable function to the value of a specified field and sets the result to another field. This method supports method chaining.
+
+### Parameters
+
+- `key` (string|int): The key of the field whose value will be processed.
+- `targetKey` (string|int): The key where the result of the callable function should be stored.
+- `callable` (callable): The function to apply to the field value. This function should accept a single argument (the value of the field) and return the processed value.
+
+### Returns
+
+- `self`: Returns the instance of the class for method chaining.
+
+### Example Usage
+
+```php
+<?php
+
+// Assuming $object is an instance of the class that contains the applyField method
+$object
+    ->set('name', 'John Doe')
+    ->applyField('name', 'uppercase_name', function($value) {
+        return strtoupper($value);
+    });
+
+echo $object->get('uppercase_name'); // Outputs: JOHN DOE
+
 ## Testing
 
 ```bash
diff --git a/src/Block.php b/src/Block.php
index a35b050..43806d1 100644
--- a/src/Block.php
+++ b/src/Block.php
@@ -146,7 +146,7 @@ public function getBlockNullable(mixed $key, mixed $defaultValue = null, string
      * You can use the dot notation for setting a nested value.
      * @param non-empty-string $charNestedKey
      */
-    public function set(int|string $key, mixed $value, string $charNestedKey = "."): void
+    public function set(int|string $key, mixed $value, string $charNestedKey = "."): self
     {
         if (is_string($key)) {
             $array = &$this->data;
@@ -165,9 +165,10 @@ public function set(int|string $key, mixed $value, string $charNestedKey = "."):
             }
 
             $array[array_shift($keys)] = $value;
-            return;
+            return $this;
         }
         $this->data[$key] = $value;
+        return $this;
     }
 
 
@@ -223,6 +224,24 @@ public function hasKey(string|int $key): bool
         return in_array($key, $keys);
     }
 
+    /**
+     * Applies a callable function to a field and sets the result to a target field.
+     *
+     * @param string|int $key The key of the field to be processed.
+     * @param string|int $targetKey The key where the result should be stored.
+     * @param callable $callable The function to apply to the field value.
+     *
+     * @return self Returns the instance of the class for method chaining.
+     */
+    public function applyField(
+        string|int $key,
+        string|int $targetKey,
+        callable $callable,
+    ): self {
+        $this->set($targetKey, $callable($this->get($key)));
+        return $this;
+    }
+
 
 
 
diff --git a/tests/Unit/BidimensionalTest.php b/tests/Unit/BidimensionalTest.php
index d825dfd..59f6c00 100644
--- a/tests/Unit/BidimensionalTest.php
+++ b/tests/Unit/BidimensionalTest.php
@@ -185,3 +185,35 @@ function (): void {
         expect($rel->get("0"))->toHaveCount(2);
     },
 );
+
+test(
+    'Apply field',
+    function (): void {
+        $table = Block::make(
+            [
+                "title" => "Title",
+                "number" => 11,
+            ],
+        );
+        $table->applyField(
+            "number",
+            "newfield",
+            fn($value): int|float => $value * 2,
+        );
+        expect($table)->toHaveCount(3);
+        expect($table->get("newfield"))->toBe(22);
+        expect($table->get("number"))->toBe(11);
+    },
+);
+
+test(
+    'Apply field2',
+    function (): void {
+        $object = Block::make();
+        $object->set('name', 'John Doe')
+            ->applyField('name', 'uppercase_name', fn($value): string => strtoupper((string) $value));
+        expect($object)->toHaveCount(2);
+        expect($object->get("uppercase_name"))->toBe("JOHN DOE");
+        expect($object->get("name"))->toBe('John Doe');
+    },
+);