diff --git a/.github/workflows/actions.yaml b/.github/workflows/actions.yaml
new file mode 100644
index 0000000..4ceccc7
--- /dev/null
+++ b/.github/workflows/actions.yaml
@@ -0,0 +1,48 @@
+name: PHP Pipeline
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  lint:
+    name: PHP Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: PHP Lint
+        run: php -l src/
+
+  phpstan:
+    name: PHPStan
+    runs-on: ubuntu-latest
+    needs: lint
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Install Composer dependencies
+        run: composer install --prefer-dist --no-scripts --no-progress --no-suggest
+
+      - name: Run PHPStan
+        run: composer verify-code
+
+  cs-fixer:
+    name: PHP CS Fixer
+    runs-on: ubuntu-latest
+    needs: phpstan
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Install Composer dependencies
+        run: composer install --prefer-dist --no-scripts --no-progress --no-suggest
+
+      - name: Run PHP CS Fixer
+        run: vendor/bin/php-cs-fixer fix --dry-run --diff src
diff --git a/.gitignore b/.gitignore
index f196cdb..7d5d911 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,7 @@
 vendor/*
 .php_cs-fixer.cache
 .phpstan.cache/
-var/
\ No newline at end of file
+var/
+composer.lock
+.php-cs-fixer.cache
+phpstan.neon
diff --git a/README.md b/README.md
index 78ed134..85e64f0 100644
--- a/README.md
+++ b/README.md
@@ -73,7 +73,7 @@ $fileContent = $client->download([
 // Delete a file from a bucket. Returns true or false.
 $fileDelete = $client->deleteFileFromArray([
     'FileId' => $file->getId()
-    
+
     // Can also identify the file via bucket and path:
     // 'BucketName' => 'my-special-bucket',
     // 'FileName' => 'path/to/file'
@@ -84,7 +84,7 @@ $fileList = $client->listFilesFromArray([
     'BucketId' => '4d2dbbe08e1e983c5e6f0d12'
 ]);
 
-// Create a new access key
+// Create a new access key.
 $capabilities = new Capabilities()
 $key = $client->createKey($accountId, $name, new Capabilities(
     [Capabilities::DELETE_BUCKETS,
@@ -93,7 +93,14 @@ $key = $client->createKey($accountId, $name, new Capabilities(
 ));
 
 $keyId = $key->getKeyId();
-$applicationKetId = $key->getApplicationKey();
+$applicationKeyId = $key->getApplicationKey();
+
+// Delete an existing access key.
+try {
+    $client->deleteKey($keyId);
+} catch (RequestException $e) {
+    // $e->getCode()
+}
 ```
 
 ## Installation
diff --git a/src/Client.php b/src/Client.php
index 3dbc70f..fa06b60 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -2,6 +2,7 @@
 
 namespace obregonco\B2;
 
+use GuzzleHttp\Exception\RequestException;
 use Illuminate\Cache\CacheManager;
 use Illuminate\Container\Container;
 use Illuminate\Filesystem\Filesystem;
@@ -354,7 +355,7 @@ public function listFilesFromArray(array $options): array
 
         // B2 returns, at most, 1000 files per "page". Loop through the pages and compile an array of File objects.
         while (true) {
-            $response = $this->request('POST', '/b2_list_file_names', [
+            $response = $this->request('POST', '/b2_list_file_versions', [
                 'json' => [
                     'bucketId' => $options['BucketId'],
                     'prefix' => $prefix,
@@ -405,7 +406,7 @@ public function listFiles(
             if (!empty($delimiter)) {
                 $params['delimiter'] = $delimiter;
             }
-            $response = $this->request('POST', '/b2_list_file_names', [
+            $response = $this->request('POST', '/b2_list_file_versions', [
                 'json' => $params,
             ]);
 
@@ -859,6 +860,47 @@ public function createKey(string $name, Capabilities $capabilities, string $buck
         );
     }
 
+    /**
+     * Deletes the key having the provided $id from Backblaze.
+     *
+     * @throws RequestException
+     * @throws \InvalidArgumentException
+     */
+    public function deleteKey(string $id): void
+    {
+        if (empty($id)) {
+            throw new \InvalidArgumentException('The key ID is empty.');
+        }
+
+        $json = [
+            'applicationKeyId' => $id,
+        ];
+
+        $this->request('POST', '/b2_delete_key', [
+            'json' => $json,
+            true
+        ]);
+    }
+
+    /**
+     * @throws \RuntimeException
+     */
+    public function retrieveKeys(): array
+    {
+        $json = [
+            'accountId' => $this->accountId,
+            'maxKeyCount' => 10000
+        ];
+
+        /** @var array */
+        $response = $this->request('POST', '/b2_list_keys', [
+            "json" => $json,
+            true
+        ]);
+
+        return $response['keys'];
+    }
+
     /**
      * Authorize the B2 account in order to get an auth token and API/download URLs.
      */
diff --git a/src/File.php b/src/File.php
index abe7c07..2aa359e 100644
--- a/src/File.php
+++ b/src/File.php
@@ -109,7 +109,7 @@ public function getUploadTimestamp()
     /**
      * @return array
      */
-    public function jsonSerialize():mixed
+    public function jsonSerialize(): mixed
     {
         return $this->asArray();
     }
diff --git a/src/Http/Client.php b/src/Http/Client.php
index a17ea3c..23b49d5 100644
--- a/src/Http/Client.php
+++ b/src/Http/Client.php
@@ -9,6 +9,8 @@
 /**
  * Client wrapper around Guzzle.
  */
+// FIXME: Class obregonco\B2\Http\Client extends @final class GuzzleHttp\Client.
+// @phpstan-ignore-next-line
 class Client extends GuzzleClient
 {
     public $retryLimit = 10;
@@ -21,6 +23,9 @@ class Client extends GuzzleClient
      *
      * @return mixed|string
      */
+    // FIXME: PHPDoc tag @return with type mixed is not subtype of native type Psr\Http\Message\ResponseInterface.
+    // FIXME: Default value of the parameter #2 $uri (string) of method obregonco\B2\Http\Client::request() is incompatible with type null.
+    // @phpstan-ignore-next-line
     public function request(string $method, $uri = '', array $options = []): ResponseInterface
     {
         $response = parent::request($method, $uri, $options);