diff --git a/CHANGELOG.md b/CHANGELOG.md
index c5fbf9478..86a8154c9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,11 @@ Fixed issues: <https://github.com/eclipse-lsp4j/lsp4j/milestone/37?closed=1>
 
 Breaking API changes:
 
+ * Type of `TextDocumentEdit.edits` changed from `List<TextEdit>` to `List<Either<TextEdit, SnippetTextEdit>>`
+ * Type of `Diagnostic.message` changed from `String` to `Either<String, MarkupContent>`
+ * Type of `DocumentFilter.pattern` changed from `String` to `Either<String, RelativePattern>`
+ * Type of `NotebookDocumentFilter.pattern` changed from `String` to `Either<String, RelativePattern>`
+
 japicmp report: <https://download.eclipse.org/lsp4j/builds/main/japicmp-report/>
 
 ### [v0.24.0 (Jan 2025)](https://github.com/eclipse-lsp4j/lsp4j/releases/tag/v0.24.0)
diff --git a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/ApplyKind.java b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/ApplyKind.java
new file mode 100644
index 000000000..6dbdad780
--- /dev/null
+++ b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/ApplyKind.java
@@ -0,0 +1,54 @@
+/******************************************************************************
+ * Copyright (c) 2025 1C-Soft LLC and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ ******************************************************************************/
+package org.eclipse.lsp4j;
+
+import org.eclipse.lsp4j.jsonrpc.Draft;
+
+/**
+ * Defines how values from a set of defaults and an individual item will be merged.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+public enum ApplyKind {
+	/**
+	 * The value from the individual item (if provided and not {@code null}) will be
+	 * used instead of the default.
+	 */
+	Replace(1),
+
+	/**
+	 * The value from the item will be merged with the default.
+	 * <p>
+	 * The specific rules for merging values are defined against each field
+	 * that supports merging.
+	 */
+	Merge(2);
+
+	private final int value;
+
+	ApplyKind(final int value) {
+		this.value = value;
+	}
+
+	public int getValue() {
+		return value;
+	}
+
+	public static ApplyKind forValue(final int value) {
+		ApplyKind[] allValues = ApplyKind.values();
+		if (value < 1 || value > allValues.length) {
+			throw new IllegalArgumentException("Illegal enum value: " + value);
+		}
+		return allValues[value - 1];
+	}
+}
diff --git a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/CodeActionTag.java b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/CodeActionTag.java
new file mode 100644
index 000000000..47e941143
--- /dev/null
+++ b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/CodeActionTag.java
@@ -0,0 +1,45 @@
+/******************************************************************************
+ * Copyright (c) 2025 1C-Soft LLC and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ ******************************************************************************/
+package org.eclipse.lsp4j;
+
+import org.eclipse.lsp4j.jsonrpc.Draft;
+
+/**
+ * Code action tags are extra annotations that tweak the behavior of a code action.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+public enum CodeActionTag {
+	/**
+	 * Marks the code action as LLM-generated.
+	 */
+	LLMGenerated(1);
+
+	private final int value;
+
+	CodeActionTag(int value) {
+		this.value = value;
+	}
+
+	public int getValue() {
+		return value;
+	}
+
+	public static CodeActionTag forValue(int value) {
+		CodeActionTag[] allValues = CodeActionTag.values();
+		if (value < 1 || value > allValues.length) {
+			throw new IllegalArgumentException("Illegal enum value: " + value);
+		}
+		return allValues[value - 1];
+	}
+}
diff --git a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/InlineCompletionTriggerKind.java b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/InlineCompletionTriggerKind.java
index 05f5d2a87..1fd137ead 100644
--- a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/InlineCompletionTriggerKind.java
+++ b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/InlineCompletionTriggerKind.java
@@ -16,7 +16,7 @@
 /**
  * Describes how an inline completion request was triggered.
  * <p>
- * @since 3.18.0
+ * Since 3.18.0
  */
 @Draft
 public enum InlineCompletionTriggerKind {
diff --git a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/MessageType.java b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/MessageType.java
index 1db3ac105..bf9967f1d 100644
--- a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/MessageType.java
+++ b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/MessageType.java
@@ -11,6 +11,8 @@
  ******************************************************************************/
 package org.eclipse.lsp4j;
 
+import org.eclipse.lsp4j.jsonrpc.Draft;
+
 public enum MessageType {
 	
 	/**
@@ -31,7 +33,15 @@ public enum MessageType {
 	/**
 	 * A log message.
 	 */
-	Log(4);
+	Log(4),
+	
+	/**
+	 * A debug message.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	Debug(5);
 	
 	private final int value;
 	
diff --git a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/Protocol.xtend b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/Protocol.xtend
index 8ea266bbd..59c9dc28a 100644
--- a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/Protocol.xtend
+++ b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/Protocol.xtend
@@ -25,6 +25,7 @@ import org.eclipse.lsp4j.adapters.InitializeParamsTypeAdapter
 import org.eclipse.lsp4j.adapters.ProgressNotificationAdapter
 import org.eclipse.lsp4j.adapters.ResourceOperationTypeAdapter
 import org.eclipse.lsp4j.adapters.SymbolInformationTypeAdapter
+import org.eclipse.lsp4j.adapters.TextEditListAdapter
 import org.eclipse.lsp4j.adapters.VersionedTextDocumentIdentifierTypeAdapter
 import org.eclipse.lsp4j.adapters.WorkspaceDocumentDiagnosticReportListAdapter
 import org.eclipse.lsp4j.adapters.WorkspaceSymbolLocationTypeAdapter
@@ -102,6 +103,22 @@ class WorkspaceEditCapabilities {
 	 */
 	WorkspaceEditChangeAnnotationSupportCapabilities changeAnnotationSupport
 
+	/**
+	 * Whether the client supports snippets as text edits.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	Boolean snippetEditSupport
+
+	/**
+	 * Whether the client supports {@link WorkspaceEditMetadata} in workspace edits.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	Boolean metadataSupport
+
 	new() {
 	}
 
@@ -391,10 +408,29 @@ class WorkspaceClientCapabilities {
 	 */
 	DiagnosticWorkspaceCapabilities diagnostics
 
+	/**
+	 * Client workspace capabilities specific to folding ranges.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	FoldingRangeWorkspaceCapabilities foldingRange
+
+	/**
+	 * Client capabilities for a text document content provider.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	TextDocumentContentCapabilities textDocumentContent
+
 	new() {
 	}
 }
 
+/**
+ * Defines which synchronization capabilities the client supports.
+ */
 @JsonRpcData
 class SynchronizationCapabilities extends DynamicRegistrationCapabilities {
 	/**
@@ -431,6 +467,23 @@ class SynchronizationCapabilities extends DynamicRegistrationCapabilities {
 	}
 }
 
+/**
+ * Defines which filters the client supports.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class FiltersCapabilities {
+	/**
+	 * The client supports relative patterns in document filters.
+	 */
+	Boolean relativePatternSupport
+
+	new() {
+	}
+}
+
 /**
  * The client supports the following {@link CompletionItem} specific capabilities.
  */
@@ -644,6 +697,22 @@ class CompletionListCapabilities {
 	 */
 	List<String> itemDefaults
 
+	/**
+	 * Specifies whether the client supports {@link CompletionList#applyKind} to
+	 * indicate how supported values from {@link CompletionList#itemDefaults}
+	 * and a completion will be combined.
+	 * <p>
+	 * If a client supports {@link CompletionList#applyKind} it must support it
+	 * for all fields that it supports that are listed in {@link CompletionApplyKind}.
+	 * This means when clients add support for new/future fields in completion items
+	 * they MUST also support merge for them if those fields are defined in
+	 * {@link CompletionApplyKind}.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	Boolean applyKindSupport
+
 	new() {
 	}
 
@@ -980,9 +1049,18 @@ class FormattingCapabilities extends DynamicRegistrationCapabilities {
 
 /**
  * Capabilities specific to the `textDocument/rangeFormatting`
+ * and `textDocument/rangesFormatting`
  */
 @JsonRpcData
 class RangeFormattingCapabilities extends DynamicRegistrationCapabilities {
+	/**
+	 * Whether the client supports formatting multiple ranges at once.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	Boolean rangesSupport
+
 	new() {
 	}
 
@@ -1169,6 +1247,30 @@ class CodeActionResolveSupportCapabilities {
 	}
 }
 
+/**
+ * Client supports the tag property on a code action. Clients
+ * supporting tags have to handle unknown tags gracefully.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class CodeActionTagSupportCapabilities {
+	/**
+	* The tags supported by the client.
+	*/
+	@NonNull
+	List<CodeActionTag> valueSet
+
+	new() {
+		this.valueSet = new ArrayList
+	}
+
+	new(@NonNull List<CodeActionTag> valueSet) {
+		this.valueSet = Preconditions.checkNotNull(valueSet, 'valueSet')
+	}
+}
+
 /**
  * Capabilities specific to the `textDocument/codeAction`
  */
@@ -1222,6 +1324,23 @@ class CodeActionCapabilities extends DynamicRegistrationCapabilities {
 	 */
 	Boolean honorsChangeAnnotations
 
+	/**
+	 * Whether the client supports documentation for a class of code actions.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	Boolean documentationSupport
+
+	/**
+	 * Client supports the tag property on a code action. Clients
+	 * supporting tags have to handle unknown tags gracefully.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	CodeActionTagSupportCapabilities tagSupport
+
 	new() {
 	}
 
@@ -1241,10 +1360,44 @@ class CodeActionCapabilities extends DynamicRegistrationCapabilities {
 }
 
 /**
- * Capabilities specific to the `textDocument/codeLens`
+ * Whether the client supports resolving additional code lens
+ * properties via a separate {@code codeLens/resolve} request.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class CodeLensResolveSupportCapabilities {
+	/**
+	 * The properties that a client can resolve lazily.
+	 */
+	@NonNull
+	List<String> properties
+
+	new() {
+		this.properties = new ArrayList
+	}
+
+	new(@NonNull List<String> properties) {
+		this.properties = Preconditions.checkNotNull(properties, 'properties')
+	}
+}
+
+/**
+ * Capabilities specific to the {@code textDocument/codeLens}
  */
 @JsonRpcData
 class CodeLensCapabilities extends DynamicRegistrationCapabilities {
+
+	/**
+	 * Whether the client supports resolving additional code lens
+	 * properties via a separate {@code codeLens/resolve} request.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	CodeLensResolveSupportCapabilities resolveSupport
+
 	new() {
 	}
 
@@ -1573,6 +1726,33 @@ class FoldingRangeCapabilities extends DynamicRegistrationCapabilities {
 	}
 }
 
+/**
+ * Client workspace capabilities specific to folding ranges.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class FoldingRangeWorkspaceCapabilities {
+	/**
+	 * Whether the client implementation supports a refresh request sent from the
+	 * server to the client.
+	 * <p>
+	 * Note that this event is global and will force the client to refresh all
+	 * folding ranges currently shown. It should be used with absolute care and is
+	 * useful for situations where a server, for example, detects a project-wide
+	 * change that requires such a calculation.
+	 */
+	Boolean refreshSupport
+
+	new() {
+	}
+
+	new(Boolean refreshSupport) {
+		this.refreshSupport = refreshSupport
+	}
+}
+
 /**
  * Capabilities specific to the {@code textDocument/prepareTypeHierarchy}.
  * <p>
@@ -2064,8 +2244,19 @@ class WorkspaceEditChangeAnnotationSupportCapabilities {
  */
 @JsonRpcData
 class TextDocumentClientCapabilities {
+	/**
+	 * Defines which synchronization capabilities the client supports.
+	 */
 	SynchronizationCapabilities synchronization
 
+	/**
+	 * Defines which filters the client supports.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	FiltersCapabilities filters
+
 	/**
 	 * Capabilities specific to the {@code textDocument/completion}
 	 */
@@ -2103,6 +2294,7 @@ class TextDocumentClientCapabilities {
 
 	/**
 	 * Capabilities specific to the {@code textDocument/rangeFormatting}
+	 * and {@code textDocument/rangesFormatting}
 	 */
 	RangeFormattingCapabilities rangeFormatting
 
@@ -2243,12 +2435,12 @@ class TextDocumentClientCapabilities {
 	DiagnosticCapabilities diagnostic
 
 	/**
-	 * Capabilities specific to the `textDocument/inlineCompletion` request.
+	 * Capabilities specific to the {@code textDocument/inlineCompletion} request.
 	 * <p>
-	 * @since 3.18.0
+	 * Since 3.18.0
 	 */
 	@Draft
-	InlineCompletionClientCapabilities inlineCompletion
+	InlineCompletionCapabilities inlineCompletion
 
 	new() {
 	}
@@ -2483,6 +2675,21 @@ final class CodeActionKind {
 	 */
 	public static val RefactorInline = 'refactor.inline'
 
+	/**
+	 * Base kind for refactoring move actions: "refactor.move"
+	 * <p>
+	 * Example move actions:
+	 * <ul>
+	 * <li>Move a function to a new file
+	 * <li>Move a property between classes
+	 * <li>Move method to base class
+	 * <li>...
+	 * </ul>
+	 * Since 3.18.0
+	 */
+	@Draft
+	public static val RefactorMove = 'refactor.move'
+
 	/**
 	 * Base kind for refactoring rewrite actions: "refactor.rewrite"
 	 * <p>
@@ -2519,6 +2726,15 @@ final class CodeActionKind {
 	 */
 	public static val SourceFixAll = 'source.fixAll'
 
+	/**
+	 * Base kind for all code actions applying to the entire notebook's scope.
+	 * Code action kinds using this should always begin with "notebook."
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	public static val Notebook = 'notebook'
+
 	private new() {}
 }
 
@@ -2600,6 +2816,14 @@ class CodeAction {
 	@JsonAdapter(JsonElementTypeAdapter.Factory)
 	Object data
 
+	/**
+	 * Tags for this code action.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	List<CodeActionTag> tags
+
 	new() {
 	}
 
@@ -2647,7 +2871,17 @@ class CodeActionDisabled {
 @JsonRpcData
 class CodeActionContext {
 	/**
-	 * An array of diagnostics.
+	 * An array of diagnostics known on the client side overlapping the range
+	 * provided to the {@code textDocument/codeAction} request. They are provided
+	 * so that the server knows which errors are currently presented to the user
+	 * for the given range. There is no guarantee that these accurately reflect the
+	 * error state of the resource. The primary parameter to compute code actions
+	 * is the provided range.
+	 * <p>
+	 * Note that the client should check the {@link DiagnosticServerCapabilities#markupMessageSupport}
+	 * server capability before sending diagnostics with markup messages to a server.
+	 * Diagnostics with markup messages should be excluded for servers that do not
+	 * support them.
 	 */
 	@NonNull
 	List<Diagnostic> diagnostics
@@ -2756,6 +2990,36 @@ class CodeLens {
 	}
 }
 
+/**
+ * Documentation for a class of code actions.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class CodeActionKindDocumentation {
+	/**
+	 * The kind of the code action being documented.
+	 * <p>
+	 * If the kind is generic, such as {@link CodeActionKind#Refactor}, the
+	 * documentation will be shown whenever any refactorings are returned. If
+	 * the kind is more specific, such as {@link CodeActionKind#RefactorExtract},
+	 * the documentation will only be shown when extract refactoring code actions
+	 * are returned.
+	 */
+	@NonNull
+	String kind
+
+	/**
+	 * Command that is used to display the documentation to the user.
+	 * <p>
+	 * The title of this documentation code action is taken
+	 * from {@link Command#title}.
+	 */
+	@NonNull
+	Command command
+}
+
 /**
  * Code Action options.
  */
@@ -2771,6 +3035,29 @@ class CodeActionOptions extends AbstractWorkDoneProgressOptions {
 	 */
 	List<String> codeActionKinds
 
+	/**
+	 * Static documentation for a class of code actions.
+	 * <p>
+	 * Documentation from the provider should be shown in the code actions
+	 * menu if either:
+	 * <ul>
+	 * <li>Code actions of {@code kind} are requested by the editor. In this case,
+	 * the editor will show the documentation that most closely matches the
+	 * requested code action kind. For example, if a provider has
+	 * documentation for both {@link CodeActionKind#Refactor} and
+	 * {@link CodeActionKind#RefactorExtract}, when the user requests
+	 * code actions for {@code RefactorExtract}, the editor will use
+	 * the documentation for {@code RefactorExtract} instead of the documentation
+	 * for {@code Refactor}.
+	 * <li>Any code actions of {@code kind} are returned by the provider.
+	 * </ul>
+	 * At most one documentation entry should be shown per provider.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	List<CodeActionKindDocumentation> documentation
+
 	/**
 	 * The server provides support to resolve additional
 	 * information for a code action.
@@ -2867,6 +3154,14 @@ class Command {
 	@NonNull
 	String title
 
+	/**
+	 * An optional tooltip.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	String tooltip
+
 	/**
 	 * The identifier of the actual command handler.
 	 */
@@ -3129,13 +3424,15 @@ class InsertReplaceRange {
 }
 
 /**
- * In many cases the items of an actual completion result share the same
+ * In many cases, the items of an actual completion result share the same
  * value for properties like {@link CompletionItem#commitCharacters} or the range of a text
  * edit. A completion list can therefore define item defaults which will
  * be used if a completion item itself doesn't specify the value.
  * <p>
  * If a completion list specifies a default value and a completion item
- * also specifies a corresponding value the one from the item is used.
+ * also specifies a corresponding value, the rules for combining these are
+ * defined by {@link CompletionList#applyKind} (if the client supports it),
+ * defaulting to {@link ApplyKind#Replace}.
  * <p>
  * Servers are only allowed to return default values if the client
  * signals support for this via the {@link CompletionListCapabilities#itemDefaults}
@@ -3176,6 +3473,71 @@ class CompletionItemDefaults {
 	}
 }
 
+/**
+ * Specifies how fields from a completion item should be combined with those
+ * from {@link CompletionList#itemDefaults}.
+ * <p>
+ * If unspecified, all fields will be treated as {@link ApplyKind#Replace}.
+ * <p>
+ * If a field's value is {@link ApplyKind#Replace}, the value from a completion item
+ * (if provided and not {@code null}) will always be used instead of the value
+ * from {@link CompletionList#itemDefaults}.
+ * <p>
+ * If a field's value is {@link ApplyKind#Merge}, the values will be merged using
+ * the rules defined against each field in {@link CompletionApplyKind}.
+ * <p>
+ * Servers are only allowed to return {@link CompletionList#applyKind} if the client
+ * signals support for this via the {@link CompletionListCapabilities#applyKindSupport}
+ * capability.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class CompletionApplyKind {
+	/**
+	 * Specifies whether {@link CompletionItem#commitCharacters commitCharacters}
+	 * on a completion will replace or be merged with those in
+	 * {@link CompletionItemDefaults#commitCharacters}.
+	 * <p>
+	 * If {@link ApplyKind#Replace}, the commit characters from the completion item
+	 * will always be used unless not provided, in which case those from
+	 * {@link CompletionItemDefaults#commitCharacters} will be used. An
+	 * empty list can be used if a completion item does not have any commit
+	 * characters and also should not use those from
+	 * {@link CompletionItemDefaults#commitCharacters}.
+	 * <p>
+	 * If {@link ApplyKind#Merge}, the commit characters for the completion will be
+	 * the union of all values in both {@link CompletionItemDefaults#commitCharacters}
+	 * and the completion's own {@link CompletionItem#commitCharacters commitCharacters}.
+	 */
+	ApplyKind commitCharacters
+
+	/**
+	 * Specifies whether the {@link CompletionItem#data data} field on a completion
+	 * will replace or be merged with data from {@link CompletionItemDefaults#data}.
+	 * <p>
+	 * If {@link ApplyKind#Replace}, the data from the completion item will be used
+	 * if provided (and not {@code null}), otherwise {@link CompletionItemDefaults#data}
+	 * will be used. An empty object can be used if a completion item does not have
+	 * any data but also should not use the value from {@link CompletionItemDefaults#data}.
+	 * <p>
+	 * If {@link ApplyKind#Merge}, a shallow merge will be performed between
+	 * {@link CompletionItemDefaults#data} and the completion's own data
+	 * using the following rules:
+	 * <ul>
+	 * <li>If a completion's {@link CompletionItem#data data} field is not provided
+	 * (or {@code null}), the entire {@link CompletionItemDefaults#data} field will be
+	 * used as-is.
+	 * <li>If a completion's {@link CompletionItem#data data} field is provided,
+	 * each field will overwrite the field of the same name in
+	 * {@link CompletionItemDefaults#data}, but no merging of nested fields
+	 * within that value will occur.
+	 * </ul>
+	 */
+	ApplyKind data
+}
+
 /**
  * Represents a collection of completion items to be presented in the editor.
  */
@@ -3193,13 +3555,15 @@ class CompletionList {
 	List<CompletionItem> items
 
 	/**
-	 * In many cases the items of an actual completion result share the same
+	 * In many cases, the items of an actual completion result share the same
 	 * value for properties like {@link CompletionItem#commitCharacters} or the range of a text
 	 * edit. A completion list can therefore define item defaults which will
 	 * be used if a completion item itself doesn't specify the value.
 	 * <p>
 	 * If a completion list specifies a default value and a completion item
-	 * also specifies a corresponding value the one from the item is used.
+	 * also specifies a corresponding value, the rules for combining these are
+	 * defined by {@link CompletionList#applyKind} (if the client supports it),
+	 * defaulting to {@link ApplyKind#Replace}.
 	 * <p>
 	 * Servers are only allowed to return default values if the client
 	 * signals support for this via the {@link CompletionListCapabilities#itemDefaults}
@@ -3209,6 +3573,28 @@ class CompletionList {
 	 */
 	CompletionItemDefaults itemDefaults
 
+	/**
+	 * Specifies how fields from a completion item should be combined with those
+	 * from {@link CompletionList#itemDefaults}.
+	 * <p>
+	 * If unspecified, all fields will be treated as {@link ApplyKind#Replace}.
+	 * <p>
+	 * If a field's value is {@link ApplyKind#Replace}, the value from a completion item
+	 * (if provided and not {@code null}) will always be used instead of the value
+	 * from {@link CompletionList#itemDefaults}.
+	 * <p>
+	 * If a field's value is {@link ApplyKind#Merge}, the values will be merged using
+	 * the rules defined against each field in {@link CompletionApplyKind}.
+	 * <p>
+	 * Servers are only allowed to return {@link CompletionList#applyKind} if the client
+	 * signals support for this via the {@link CompletionListCapabilities#applyKindSupport}
+	 * capability.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	CompletionApplyKind applyKind
+
 	new() {
 		this(new ArrayList)
 	}
@@ -3330,9 +3716,14 @@ class Diagnostic {
 
 	/**
 	 * The diagnostic's message.
+	 * <p>
+	 * Since 3.18.0 - support for {@link MarkupContent}. This is guarded by the client
+	 * capability {@link DiagnosticCapabilities#markupMessageSupport}. If a client does not
+	 * signal this capability, servers should not send {@link MarkupContent} diagnostic messages
+	 * back to the client.
 	 */
 	@NonNull
-	String message
+	Either<String, MarkupContent> message
 
 	/**
 	 * Additional metadata about the diagnostic.
@@ -4121,11 +4512,61 @@ class DocumentRangeFormattingParams implements WorkDoneProgressParams {
 	}
 }
 
+/**
+ * The document ranges formatting request is sent from the client to the server to format
+ * multiple ranges at once in a document.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class DocumentRangesFormattingParams implements WorkDoneProgressParams {
+	/**
+	 * An optional token that a server can use to report work done progress.
+	 */
+	Either<String, Integer> workDoneToken
+
+	/**
+	 * The document to format.
+	 */
+	@NonNull
+	TextDocumentIdentifier textDocument
+
+	/**
+	 * The format options.
+	 */
+	@NonNull
+	FormattingOptions options
+
+	/**
+	 * The ranges to format.
+	 */
+	@NonNull
+	List<Range> ranges
+
+	new() {
+		this.ranges = new ArrayList
+	}
+
+	new(@NonNull TextDocumentIdentifier textDocument, @NonNull FormattingOptions options, @NonNull List<Range> ranges) {
+		this.textDocument = Preconditions.checkNotNull(textDocument, 'textDocument')
+		this.options = Preconditions.checkNotNull(options, 'options')
+		this.ranges = Preconditions.checkNotNull(ranges, 'ranges')
+	}
+}
+
 /**
  * Document range formatting options.
  */
 @JsonRpcData
 class DocumentRangeFormattingOptions extends AbstractWorkDoneProgressOptions {
+	/**
+	 * Whether the server supports formatting multiple ranges at once.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	Boolean rangesSupport
 }
 
 /**
@@ -4133,6 +4574,13 @@ class DocumentRangeFormattingOptions extends AbstractWorkDoneProgressOptions {
  */
 @JsonRpcData
 class DocumentRangeFormattingRegistrationOptions extends AbstractTextDocumentRegistrationAndWorkDoneProgressOptions {
+	/**
+	 * Whether the server supports formatting multiple ranges at once.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	Boolean rangesSupport
 }
 
 /**
@@ -5699,6 +6147,12 @@ final class SemanticTokenTypes {
 	 */
 	public static val Decorator = 'decorator'
 
+	/**
+	 * Since 3.18.0
+	 */
+	@Draft
+	public static val Label = 'label'
+
 	private new() {
 	}
 }
@@ -6070,20 +6524,28 @@ class ServerCapabilities {
 	 */
 	Either<Boolean, InlineValueRegistrationOptions> inlineValueProvider
 
+	/**
+	 * The server has support for pull model diagnostics.
+	 * <p>
+	 * Since 3.17.0
+	 */
+	DiagnosticRegistrationOptions diagnosticProvider
+
 	/**
 	 * The server provides inline completions.
 	 * <p>
-	 * @since 3.18.0
+	 * Since 3.18.0
 	 */
 	@Draft
 	Either<Boolean, InlineCompletionRegistrationOptions> inlineCompletionProvider
 
 	/**
-	 * The server has support for pull model diagnostics.
+	 * Text document specific server capabilities.
 	 * <p>
-	 * Since 3.17.0
+	 * Since 3.18.0
 	 */
-	DiagnosticRegistrationOptions diagnosticProvider
+	@Draft
+	TextDocumentServerCapabilities textDocument
 
 	/**
 	 * Experimental server capabilities.
@@ -6111,6 +6573,14 @@ class WorkspaceServerCapabilities {
 	 */
 	FileOperationsServerCapabilities fileOperations
 
+	/**
+	 * Text document content provider options.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	TextDocumentContentRegistrationOptions textDocumentContent
+
 	new() {
 	}
 
@@ -6119,6 +6589,24 @@ class WorkspaceServerCapabilities {
 	}
 }
 
+/**
+ * Text document specific server capabilities.
+ * <p>
+ * Since 3.18.0.
+ */
+@Draft
+@JsonRpcData
+class TextDocumentServerCapabilities {
+
+	/**
+	 * Capabilities specific to the diagnostic pull model.
+	 */
+	DiagnosticServerCapabilities diagnostic
+
+	new() {
+	}
+}
+
 /**
  * The show message request is sent from a server to a client to ask the client to display a particular message in the
  * user class. In addition to the show message notification the request allows to pass actions and to wait for an
@@ -7217,15 +7705,21 @@ class TextDocumentEdit {
 	VersionedTextDocumentIdentifier textDocument
 
 	/**
-	 * The edits to be applied
+	 * The edits to be applied.
+	 * <p>
+	 * Since 3.18 - support for {@link SnippetTextEdit}. This is guarded by the
+	 * client capability {@link WorkspaceEditCapabilities#snippetEditSupport}.
+	 * If a client does not signal this capability, servers should not send
+	 * {@link SnippetTextEdit} snippets back to the client.
 	 */
 	@NonNull
-	List<TextEdit> edits
+	@JsonAdapter(TextEditListAdapter)
+	List<Either<TextEdit, SnippetTextEdit>> edits
 
 	new() {
 	}
 
-	new(@NonNull VersionedTextDocumentIdentifier textDocument, @NonNull List<TextEdit> edits) {
+	new(@NonNull VersionedTextDocumentIdentifier textDocument, @NonNull List<Either<TextEdit, SnippetTextEdit>> edits) {
 		this.textDocument = Preconditions.checkNotNull(textDocument, 'textDocument')
 		this.edits = Preconditions.checkNotNull(edits, 'edits')
 	}
@@ -7603,28 +8097,33 @@ class RegistrationParams {
 
 /**
  * A document filter denotes a document through properties like language, schema or pattern.
+ * <p>
+ * At least one of the properties {@link #language}, {@link #scheme}, or {@link #pattern} must be set.
  */
 @JsonRpcData
 class DocumentFilter {
 	/**
-	 * A language id, like `typescript`.
+	 * A language id, like {@code typescript}.
 	 */
 	String language
 
 	/**
-	 * A uri scheme, like `file` or `untitled`.
+	 * A uri scheme, like {@code file} or {@code untitled}.
 	 */
 	String scheme
 
 	/**
-	 * A glob pattern, like `*.{ts,js}`.
+	 * A glob pattern, like <code>*.{ts,js}</code>.
+	 * <p>
+	 * Since 3.18 - support for relative patterns, which depends on the
+	 * client capability {@link FiltersCapabilities#relativePatternSupport}.
 	 */
-	String pattern
+	Either<String, RelativePattern> pattern
 
 	new() {
 	}
 
-	new(String language, String scheme, String pattern) {
+	new(String language, String scheme, Either<String, RelativePattern> pattern) {
 		this.language = language
 		this.scheme = scheme
 		this.pattern = pattern
@@ -7912,6 +8411,23 @@ class ExecuteCommandParams implements WorkDoneProgressParams {
 class ExecuteCommandRegistrationOptions extends ExecuteCommandOptions {
 }
 
+/**
+ * Additional data about a workspace edit.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class WorkspaceEditMetadata {
+	/**
+	 * Signal to the editor that this edit is a refactoring.
+	 */
+	Boolean isRefactoring
+
+	new() {
+	}
+}
+
 /**
  * The workspace/applyEdit request is sent from the server to the client to modify resource on the client side.
  */
@@ -7930,6 +8446,14 @@ class ApplyWorkspaceEditParams {
 	 */
 	String label
 
+	/**
+	 * Additional data about the edit.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	WorkspaceEditMetadata metadata
+
 	new() {
 	}
 
@@ -10017,6 +10541,14 @@ class DiagnosticCapabilities extends DynamicRegistrationCapabilities {
 	 */
 	Boolean relatedDocumentSupport
 
+	/**
+	 * Whether the client supports {@link MarkupContent} in diagnostic messages.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	Boolean markupMessageSupport
+
 	new() {
 	}
 
@@ -10030,6 +10562,24 @@ class DiagnosticCapabilities extends DynamicRegistrationCapabilities {
 	}
 }
 
+/**
+ * Server capabilities specific to the diagnostic pull model.
+ * <p>
+ * Since 3.18.0.
+ */
+@Draft
+@JsonRpcData
+class DiagnosticServerCapabilities {
+
+	/**
+	 * Whether the server supports {@link MarkupContent} in diagnostic messages.
+	 */
+	Boolean markupMessageSupport
+
+	new() {
+	}
+}
+
 /**
  * Diagnostic registration options.
  * <p>
@@ -10709,7 +11259,7 @@ class NotebookDocumentFilter {
 	/**
 	 * A glob pattern.
 	 */
-	String pattern
+	Either<String, RelativePattern> pattern
 
 	new() {
 	}
@@ -11204,7 +11754,7 @@ final class StringValueKind {
  * the end of the snippet. Variables are defined with `$name` and
  * `${name:default value}`.
  * <p>
- * @since 3.18.0
+ * Since 3.18.0
  */
 @Draft
 @JsonRpcData
@@ -11235,11 +11785,11 @@ class StringValue {
 /**
  * Client capabilities specific to inline completions.
  * <p>
- * @since 3.18.0
+ * Since 3.18.0
  */
 @Draft
 @JsonRpcData
-class InlineCompletionClientCapabilities extends DynamicRegistrationCapabilities {
+class InlineCompletionCapabilities extends DynamicRegistrationCapabilities {
 	new() {
 	}
 
@@ -11251,7 +11801,7 @@ class InlineCompletionClientCapabilities extends DynamicRegistrationCapabilities
 /**
  * Inline completion options used during static or dynamic registration.
  * <p>
- * @since 3.18.0
+ * Since 3.18.0
  */
 @Draft
 @JsonRpcData
@@ -11273,7 +11823,7 @@ class InlineCompletionRegistrationOptions extends AbstractTextDocumentRegistrati
 /**
  * A parameter literal used in inline completion requests.
  * <p>
- * @since 3.18.0
+ * Since 3.18.0
  */
 @Draft
 @JsonRpcData
@@ -11298,7 +11848,7 @@ class InlineCompletionParams extends TextDocumentPositionAndWorkDoneProgressPara
  * Provides information about the context in which an inline completion was
  * requested.
  * <p>
- * @since 3.18.0
+ * Since 3.18.0
  */
 @Draft
 @JsonRpcData
@@ -11341,7 +11891,7 @@ class InlineCompletionContext {
 /**
  * Describes the currently selected completion item.
  * <p>
- * @since 3.18.0
+ * Since 3.18.0
  */
 @Draft
 @JsonRpcData
@@ -11371,7 +11921,7 @@ class SelectedCompletionInfo {
 /**
  * Represents a collection of {@link InlineCompletionItem} to be presented in the editor.
  * <p>
- * @since 3.18.0
+ * Since 3.18.0
  */
 @Draft
 @JsonRpcData
@@ -11394,7 +11944,7 @@ class InlineCompletionList {
  * An inline completion item represents a text snippet that is proposed inline
  * to complete text that is being typed.
  * <p>
- * @since 3.18.0
+ * Since 3.18.0
  */
 @Draft
 @JsonRpcData
@@ -11438,3 +11988,154 @@ class InlineCompletionItem {
 		this.insertText = Preconditions.checkNotNull(insertText, 'insertText')
 	}
 }
+
+/**
+ * An interactive text edit.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class SnippetTextEdit {
+
+	/**
+	 * The range of the text document to be manipulated.
+	 */
+	@NonNull
+	Range range
+
+	/**
+	 * The snippet to be inserted.
+	 */
+	@NonNull
+	StringValue snippet
+
+	/**
+	 * The actual identifier of the snippet edit.
+	 */
+	String annotationId
+
+	new() {
+	}
+
+	new(@NonNull Range range, @NonNull StringValue snippet) {
+		this.range = Preconditions.checkNotNull(range, 'range')
+		this.snippet = Preconditions.checkNotNull(snippet, 'snippet')
+	}
+
+	new(@NonNull Range range, @NonNull StringValue snippet, String annotationId) {
+		this(range, snippet)
+		this.annotationId = annotationId
+	}
+}
+
+/**
+ * Client capabilities for a text document content provider.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class TextDocumentContentCapabilities extends DynamicRegistrationCapabilities {
+	new() {
+	}
+
+	new(Boolean dynamicRegistration) {
+		super(dynamicRegistration)
+	}
+}
+
+/**
+ * Text document content provider registration options.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class TextDocumentContentRegistrationOptions {
+	/**
+	 * The id used to register the request. The id can be used to deregister
+	 * the request again. See also {@link Registration#id}.
+	 */
+	String id
+
+	@NonNull
+	List<String> schemes
+
+	new() {
+		this.schemes = new ArrayList
+	}
+
+	new(@NonNull List<String> schemes) {
+		this.schemes = Preconditions.checkNotNull(schemes, 'schemes')
+	}
+}
+
+/**
+ * Parameters for the {@code workspace/textDocumentContent} request.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class TextDocumentContentParams {
+	/**
+	 * The uri of the text document.
+	 */
+	@NonNull
+	String uri
+
+	new() {
+	}
+
+	new(@NonNull String uri) {
+		this.uri = Preconditions.checkNotNull(uri, 'uri')
+	}
+}
+
+/**
+ * Result of the {@code workspace/textDocumentContent} request.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class TextDocumentContentResult {
+	/**
+	 * The text content of the text document. Please note, that the content of
+	 * any subsequent open notifications for the text document might differ
+	 * from the returned content due to whitespace and line ending
+	 * normalizations done on the client.
+	 */
+	@NonNull
+	String text
+
+	new() {
+	}
+
+	new(@NonNull String text) {
+		this.text = Preconditions.checkNotNull(text, 'text')
+	}
+}
+
+/**
+ * Parameters for the {@code workspace/textDocumentContent/refresh} request.
+ * <p>
+ * Since 3.18.0
+ */
+@Draft
+@JsonRpcData
+class TextDocumentContentRefreshParams {
+	/**
+	 * The uri of the text document to refresh.
+	 */
+	@NonNull
+	String uri
+
+	new() {
+	}
+
+	new(@NonNull String uri) {
+		this.uri = Preconditions.checkNotNull(uri, 'uri')
+	}
+}
diff --git a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/adapters/TextEditListAdapter.java b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/adapters/TextEditListAdapter.java
new file mode 100644
index 000000000..cfc606f0d
--- /dev/null
+++ b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/adapters/TextEditListAdapter.java
@@ -0,0 +1,40 @@
+/******************************************************************************
+ * Copyright (c) 2025 1C-Soft LLC and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ ******************************************************************************/
+package org.eclipse.lsp4j.adapters;
+
+import java.util.ArrayList;
+
+import org.eclipse.lsp4j.SnippetTextEdit;
+import org.eclipse.lsp4j.TextEdit;
+import org.eclipse.lsp4j.jsonrpc.json.adapters.CollectionTypeAdapter;
+import org.eclipse.lsp4j.jsonrpc.json.adapters.EitherTypeAdapter;
+import org.eclipse.lsp4j.jsonrpc.json.adapters.EitherTypeAdapter.PropertyChecker;
+import org.eclipse.lsp4j.jsonrpc.messages.Either;
+
+import com.google.gson.Gson;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+
+public class TextEditListAdapter implements TypeAdapterFactory {
+
+	private static final TypeToken<Either<TextEdit, SnippetTextEdit>> ELEMENT_TYPE = new TypeToken<>() {};
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
+		final var leftChecker = new PropertyChecker("newText");
+		final var rightChecker = new PropertyChecker("snippet");
+		final var elementTypeAdapter = new EitherTypeAdapter<>(gson, ELEMENT_TYPE, leftChecker, rightChecker);
+		return (TypeAdapter<T>) new CollectionTypeAdapter<>(gson, ELEMENT_TYPE.getType(), elementTypeAdapter, ArrayList::new);
+	}
+}
diff --git a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/LanguageClient.java b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/LanguageClient.java
index ee907cc96..de0e97e25 100644
--- a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/LanguageClient.java
+++ b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/LanguageClient.java
@@ -26,9 +26,11 @@
 import org.eclipse.lsp4j.ShowDocumentParams;
 import org.eclipse.lsp4j.ShowDocumentResult;
 import org.eclipse.lsp4j.ShowMessageRequestParams;
+import org.eclipse.lsp4j.TextDocumentContentRefreshParams;
 import org.eclipse.lsp4j.UnregistrationParams;
 import org.eclipse.lsp4j.WorkDoneProgressCreateParams;
 import org.eclipse.lsp4j.WorkspaceFolder;
+import org.eclipse.lsp4j.jsonrpc.Draft;
 import org.eclipse.lsp4j.jsonrpc.services.JsonNotification;
 import org.eclipse.lsp4j.jsonrpc.services.JsonRequest;
 
@@ -250,4 +252,32 @@ default CompletableFuture<Void> refreshInlineValues() {
 	default CompletableFuture<Void> refreshDiagnostics() {
 		throw new UnsupportedOperationException();
 	}
+
+	/**
+	 * The {@code workspace/foldingRange/refresh} request is sent from the server to the client.
+	 * Servers can use it to ask clients to refresh the folding ranges currently shown in editors.
+	 * As a result the client should ask the server to recompute the folding ranges for these editors.
+	 * This is useful if a server detects a configuration change which requires a re-calculation of
+	 * all folding ranges. Note that the client still has the freedom to delay the re-calculation of
+	 * the folding ranges if, for example, an editor is currently not visible.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	@JsonRequest("workspace/foldingRange/refresh")
+	default CompletableFuture<Void> refreshFoldingRanges() {
+		throw new UnsupportedOperationException();
+	}
+
+	/**
+	 * The {@code workspace/textDocumentContent/refresh} request is sent from the server to the client
+	 * to refresh the content of a specific text document.
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	@JsonRequest("workspace/textDocumentContent/refresh")
+	default CompletableFuture<Void> refreshTextDocumentContent(TextDocumentContentRefreshParams params) {
+		throw new UnsupportedOperationException();
+	}
 }
diff --git a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/TextDocumentService.java b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/TextDocumentService.java
index 6086787e8..2f876426f 100644
--- a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/TextDocumentService.java
+++ b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/TextDocumentService.java
@@ -47,6 +47,7 @@
 import org.eclipse.lsp4j.DocumentLinkParams;
 import org.eclipse.lsp4j.DocumentOnTypeFormattingParams;
 import org.eclipse.lsp4j.DocumentRangeFormattingParams;
+import org.eclipse.lsp4j.DocumentRangesFormattingParams;
 import org.eclipse.lsp4j.DocumentSymbol;
 import org.eclipse.lsp4j.DocumentSymbolCapabilities;
 import org.eclipse.lsp4j.DocumentSymbolParams;
@@ -322,6 +323,20 @@ default CompletableFuture<List<? extends TextEdit>> rangeFormatting(DocumentRang
 		throw new UnsupportedOperationException();
 	}
 
+	/**
+	 * The document ranges formatting request is sent from the client to the
+	 * server to format multiple ranges at once in a document.
+	 * <p>
+	 * Registration Options: {@link org.eclipse.lsp4j.DocumentRangeFormattingRegistrationOptions}
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	@JsonRequest
+	default CompletableFuture<List<? extends TextEdit>> rangesFormatting(DocumentRangesFormattingParams params) {
+		throw new UnsupportedOperationException();
+	}
+
 	/**
 	 * The document on type formatting request is sent from the client to the
 	 * server to format parts of the document during typing.
diff --git a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/WorkspaceService.java b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/WorkspaceService.java
index 34dba7e15..fb92a645c 100644
--- a/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/WorkspaceService.java
+++ b/org.eclipse.lsp4j/src/main/java/org/eclipse/lsp4j/services/WorkspaceService.java
@@ -22,12 +22,15 @@
 import org.eclipse.lsp4j.ExecuteCommandParams;
 import org.eclipse.lsp4j.RenameFilesParams;
 import org.eclipse.lsp4j.SymbolInformation;
+import org.eclipse.lsp4j.TextDocumentContentParams;
+import org.eclipse.lsp4j.TextDocumentContentResult;
 import org.eclipse.lsp4j.WorkspaceDiagnosticParams;
 import org.eclipse.lsp4j.WorkspaceDiagnosticReport;
 import org.eclipse.lsp4j.WorkspaceEdit;
 import org.eclipse.lsp4j.WorkspaceSymbol;
 import org.eclipse.lsp4j.WorkspaceSymbolParams;
 import org.eclipse.lsp4j.adapters.WorkspaceSymbolResponseAdapter;
+import org.eclipse.lsp4j.jsonrpc.Draft;
 import org.eclipse.lsp4j.jsonrpc.json.ResponseJsonAdapter;
 import org.eclipse.lsp4j.jsonrpc.messages.Either;
 import org.eclipse.lsp4j.jsonrpc.services.JsonNotification;
@@ -193,4 +196,18 @@ default void didDeleteFiles(DeleteFilesParams params) {
 	default CompletableFuture<WorkspaceDiagnosticReport> diagnostic(WorkspaceDiagnosticParams params) {
 		throw new UnsupportedOperationException();
 	}
+
+	/**
+	 * The {@code workspace/textDocumentContent} request is sent from the client to the server to dynamically fetch
+	 * the content of a text document. Clients should treat the content returned from this request as read-only.
+	 * <p>
+	 * Registration Options: {@link org.eclipse.lsp4j.TextDocumentContentRegistrationOptions}
+	 * <p>
+	 * Since 3.18.0
+	 */
+	@Draft
+	@JsonRequest
+	default CompletableFuture<TextDocumentContentResult> textDocumentContent(TextDocumentContentParams params) {
+		throw new UnsupportedOperationException();
+	}
 }
diff --git a/org.eclipse.lsp4j/src/test/java/org/eclipse/lsp4j/test/services/JsonParseTest.xtend b/org.eclipse.lsp4j/src/test/java/org/eclipse/lsp4j/test/services/JsonParseTest.xtend
index 3c8d8e532..5d260da5b 100644
--- a/org.eclipse.lsp4j/src/test/java/org/eclipse/lsp4j/test/services/JsonParseTest.xtend
+++ b/org.eclipse.lsp4j/src/test/java/org/eclipse/lsp4j/test/services/JsonParseTest.xtend
@@ -76,6 +76,8 @@ import org.eclipse.lsp4j.SignatureHelp
 import org.eclipse.lsp4j.SignatureHelpCapabilities
 import org.eclipse.lsp4j.SignatureInformation
 import org.eclipse.lsp4j.SignatureInformationCapabilities
+import org.eclipse.lsp4j.SnippetTextEdit
+import org.eclipse.lsp4j.StringValue
 import org.eclipse.lsp4j.SymbolInformation
 import org.eclipse.lsp4j.SymbolKind
 import org.eclipse.lsp4j.SymbolKindCapabilities
@@ -855,6 +857,22 @@ class JsonParseTest {
 										}
 									},
 									"newText": "asdfqweryxcv"
+								},
+								{
+									"range": {
+										"start": {
+											"character": 33,
+											"line": 5
+										},
+										"end": {
+											"character": 37,
+											"line": 5
+										}
+									},
+									"snippet": {
+										"kind": "snippet",
+										"value": "abra$0cadabra"
+									}
 								}
 							]
 						}
@@ -883,13 +901,23 @@ class JsonParseTest {
 					Either.forLeft(new TextDocumentEdit => [
 						textDocument = new VersionedTextDocumentIdentifier("file:/baz.txt", 17)
 						edits = newArrayList(
-							new TextEdit => [
+							Either.forLeft(new TextEdit => [
 								range = new Range => [
 									start = new Position(3, 32)
 									end = new Position(3, 35)
 								]
 								newText = "asdfqweryxcv"
-							]
+							]),
+							Either.forRight(new SnippetTextEdit => [
+								range = new Range => [
+									start = new Position(5, 33)
+									end = new Position(5, 37)
+								]
+								snippet = new StringValue => [
+									kind = "snippet"
+									value = "abra$0cadabra"
+								]
+							])
 						)
 					])
 				)