diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 5a9a2a4..04f1099 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -13,17 +13,17 @@ jobs:
       matrix:
         include:
           - php: '7.4'
-            os: ubuntu-18.04
+            os: ubuntu-22.04
           - php: '8.0'
-            os: ubuntu-18.04
+            os: ubuntu-22.04
           - php: '8.1'
-            os: ubuntu-18.04
+            os: ubuntu-22.04
     steps:
       - uses: actions/checkout@v2
       - name: Setup Node.js
         uses: actions/setup-node@v2
         with:
-          node-version: '14.15.3' # renovate:keep-up-to-date
+          node-version: '16.14.2' # renovate:keep-up-to-date
       - name: Install npm dependencies
         run: npm ci
       - name: Setup PHP
@@ -32,6 +32,8 @@ jobs:
           php-version: ${{ matrix.php }}
           extensions: ${{ matrix.xdebug }}, ast
           tools: composer
+      - name: Php Lint
+        uses: michaelw90/PHP-Lint@2.1.0
       - name: Composer Install
         run: COMPOSER_ROOT_VERSION=dev-master composer install --prefer-dist --no-interaction
       - name: phpcs
@@ -55,7 +57,7 @@ jobs:
 #      - name: Setup Node.js
 #        uses: actions/setup-node@v2
 #        with:
-#          node-version: '14.15.3' # renovate:keep-up-to-date
+#          node-version: '16.14.2' # renovate:keep-up-to-date
 #      - name: Install npm dependencies
 #        run: npm ci
 #      - name: Build VS Code extension
diff --git a/src/CompletionItem.php b/src/CompletionItem.php
index 3e9757a..fcb3e1c 100644
--- a/src/CompletionItem.php
+++ b/src/CompletionItem.php
@@ -3,7 +3,9 @@
 
 namespace LanguageServerProtocol;
 
-class CompletionItem
+use JsonSerializable;
+
+class CompletionItem implements JsonSerializable
 {
     /**
      * The label of this completion item. By default
@@ -245,4 +247,18 @@ public function __construct(
         $this->data = $data;
         $this->insertTextFormat = $insertTextFormat;
     }
+
+    /**
+     * This is needed because VSCode Does not like nulls
+     * meaning if a null is sent then this will not compute
+     *
+     * @return mixed
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+        return array_filter(get_object_vars($this), function ($v) {
+            return $v !== null;
+        });
+    }
 }
diff --git a/src/Diagnostic.php b/src/Diagnostic.php
index d355127..464216c 100644
--- a/src/Diagnostic.php
+++ b/src/Diagnostic.php
@@ -2,11 +2,13 @@
 
 namespace LanguageServerProtocol;
 
+use JsonSerializable;
+
 /**
  * Represents a diagnostic, such as a compiler error or warning. Diagnostic objects are only valid in the scope of a
  * resource.
  */
-class Diagnostic
+class Diagnostic implements JsonSerializable
 {
     /**
      * The range at which the message applies.
@@ -118,4 +120,18 @@ public function __construct(
         $this->relatedInformation = $relatedInformation;
         $this->data = $data;
     }
+
+    /**
+     * This is needed because VSCode Does not like nulls
+     * meaning if a null is sent then this will not compute
+     *
+     * @return mixed
+     */
+    #[\ReturnTypeWillChange]
+    public function jsonSerialize()
+    {
+        return array_filter(get_object_vars($this), function ($v) {
+            return $v !== null;
+        });
+    }
 }
diff --git a/src/InlineValueClientCapabilities.php b/src/InlineValueClientCapabilities.php
new file mode 100644
index 0000000..1f9c41a
--- /dev/null
+++ b/src/InlineValueClientCapabilities.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace LanguageServerProtocol;
+
+class InlineValueClientCapabilities
+{
+
+    /**
+     * Whether implementation supports dynamic registration for inline value providers.
+     *
+     * @var bool|null
+     */
+    public $dynamicRegistration;
+
+    public function __construct(
+        ?bool $dynamicRegistration = null
+    ) {
+        $this->dynamicRegistration = $dynamicRegistration;
+    }
+}
diff --git a/src/InlineValueContext.php b/src/InlineValueContext.php
new file mode 100644
index 0000000..8a7dbb1
--- /dev/null
+++ b/src/InlineValueContext.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace LanguageServerProtocol;
+
+/**
+ * @since 3.17.0
+ */
+class InlineValueContext
+{
+    /**
+     * The stack frame (as a DAP Id) where the execution has stopped.
+     *
+     * @var int|null
+     */
+    public $frameId;
+
+    /**
+     * The document range where execution has stopped.
+     * Typically the end position of the range denotes the line where the
+     * inline values are shown.
+     *
+     * @var Range|null
+     */
+    public $stoppedLocation;
+
+    /**
+     * @param int|null $frameId stack frame Id
+     * @param Range|null $stoppedLocation Range
+     */
+    public function __construct(?int $frameId = null, ?\LanguageServerProtocol\Range $stoppedLocation = null)
+    {
+        /** @psalm-suppress PossiblyNullPropertyAssignmentValue */
+        $this->frameId = $frameId;
+        /** @psalm-suppress PossiblyNullPropertyAssignmentValue */
+        $this->stoppedLocation = $stoppedLocation;
+    }
+}
diff --git a/src/InlineValueEvaluatableExpression.php b/src/InlineValueEvaluatableExpression.php
new file mode 100644
index 0000000..21e8250
--- /dev/null
+++ b/src/InlineValueEvaluatableExpression.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace LanguageServerProtocol;
+
+/**
+ * Provide an inline value through an expression evaluation.
+ *
+ * If only a range is specified, the expression will be extracted from the
+ * underlying document.
+ *
+ * An optional expression can be used to override the extracted expression.
+ *
+ * @since 3.17.0
+ */
+class InlineValueEvaluatableExpression
+{
+    /**
+     * The document range for which the inline value applies.
+     * The range is used to extract the evaluatable expression from the
+     * underlying document.
+     *
+     * @var Range|null
+     */
+    public $range;
+
+    /**
+     * If specified the expression overrides the extracted expression.
+     *
+     * @var string|null
+     */
+    public $expression;
+
+    /**
+     * @param Range|null $range Range
+     * @param string|null $expression expression
+     */
+    public function __construct(?\LanguageServerProtocol\Range $range = null, ?string $expression = null)
+    {
+        /** @psalm-suppress PossiblyNullPropertyAssignmentValue */
+        $this->range = $range;
+        $this->expression = $expression;
+    }
+}
diff --git a/src/InlineValueText.php b/src/InlineValueText.php
new file mode 100644
index 0000000..ccf8f0b
--- /dev/null
+++ b/src/InlineValueText.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace LanguageServerProtocol;
+
+/**
+ * Provide inline value as text.
+ *
+ * @since 3.17.0
+ */
+class InlineValueText
+{
+    /**
+     * The document range for which the inline value applies.
+     *
+     * @var Range|null
+     */
+    public $range;
+
+    /**
+     * The text of the inline value.
+     *
+     * @var string|null
+     */
+    public $text;
+
+    /**
+     * @param Range|null $range Range
+     * @param string|null $text Text
+     */
+    public function __construct(?\LanguageServerProtocol\Range $range = null, ?string $text = null)
+    {
+        /** @psalm-suppress PossiblyNullPropertyAssignmentValue */
+        $this->range = $range;
+        /** @psalm-suppress PossiblyNullPropertyAssignmentValue */
+        $this->text = $text;
+    }
+}
diff --git a/src/InlineValueVariableLookup.php b/src/InlineValueVariableLookup.php
new file mode 100644
index 0000000..5c4b04e
--- /dev/null
+++ b/src/InlineValueVariableLookup.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace LanguageServerProtocol;
+
+/**
+ * Provide inline value through a variable lookup.
+ *
+ * If only a range is specified, the variable name will be extracted from
+ * the underlying document.
+ *
+ * An optional variable name can be used to override the extracted name.
+ *
+ * @since 3.17.0
+ */
+class InlineValueVariableLookup
+{
+    /**
+     * The document range for which the inline value applies.
+     * The range is used to extract the variable name from the underlying
+     * document.
+     *
+     * @var Range|null
+     */
+    public $range;
+
+    /**
+     * If specified the name of the variable to look up.
+     *
+     * @var string|null
+     */
+    public $variableName;
+
+    /**
+     *  How to perform the lookup.
+     *
+     * @var bool|null
+     */
+    public $caseSensitiveLookup;
+
+    /**
+     * @param Range|null $range Range
+     * @param string|null $variableName variableName
+     * @param bool|null $caseSensitiveLookup caseSensitiveLookup
+     */
+    public function __construct(
+        ?\LanguageServerProtocol\Range $range = null,
+        ?string $variableName = null,
+        ?bool $caseSensitiveLookup = null
+    ) {
+        /** @psalm-suppress PossiblyNullPropertyAssignmentValue */
+        $this->range = $range;
+        $this->variableName = $variableName;
+        /** @psalm-suppress PossiblyNullPropertyAssignmentValue */
+        $this->caseSensitiveLookup = $caseSensitiveLookup;
+    }
+}
diff --git a/src/TextDocumentClientCapabilities.php b/src/TextDocumentClientCapabilities.php
index 790243b..1713268 100644
--- a/src/TextDocumentClientCapabilities.php
+++ b/src/TextDocumentClientCapabilities.php
@@ -207,6 +207,15 @@ class TextDocumentClientCapabilities
      */
     public $moniker;
 
+    /**
+     * Capabilities specific to the `textDocument/inlineValue` request.
+     *
+     * @since 3.17.0
+     *
+     * @var InlineValueClientCapabilities|null
+     */
+    public $inlineValue;
+
     public function __construct(
         ?\LanguageServerProtocol\TextDocumentSyncClientCapabilities $synchronization = null,
         ?\LanguageServerProtocol\CompletionClientCapabilities $completion = null,
@@ -233,7 +242,8 @@ public function __construct(
         ?\LanguageServerProtocol\LinkedEditingRangeClientCapabilities $linkedEditingRange = null,
         ?\LanguageServerProtocol\CallHierarchyClientCapabilities $callHierarchy = null,
         ?\LanguageServerProtocol\SemanticTokensClientCapabilities $semanticTokens = null,
-        ?\LanguageServerProtocol\MonikerClientCapabilities $moniker = null
+        ?\LanguageServerProtocol\MonikerClientCapabilities $moniker = null,
+        ?\LanguageServerProtocol\InlineValueClientCapabilities $inlineValue = null
     ) {
         $this->synchronization = $synchronization;
         $this->completion = $completion;
@@ -261,5 +271,6 @@ public function __construct(
         $this->callHierarchy = $callHierarchy;
         $this->semanticTokens = $semanticTokens;
         $this->moniker = $moniker;
+        $this->inlineValue = $inlineValue;
     }
 }