diff --git a/extensions/typescript-language-features/src/features/semanticColoring.ts b/extensions/typescript-language-features/src/features/semanticColoring.ts
index 171d4b5c8d1..950e8265f0c 100644
--- a/extensions/typescript-language-features/src/features/semanticColoring.ts
+++ b/extensions/typescript-language-features/src/features/semanticColoring.ts
@@ -112,47 +112,5 @@ export function register(
 	selector: vscode.DocumentSelector,
 	client: ITypeScriptServiceClient
 ) {
-	const provider = new SemanticColoringProvider(client);
-
-
-	const run = async () => {
-		const ed = vscode.window.activeTextEditor;
-		if (!ed) {
-			return;
-		}
-		// const doc = ed.document;
-		const cancellationTokenSource = new vscode.CancellationTokenSource();
-		provider.provideSemanticColoring(ed.document, cancellationTokenSource.token);
-		// const file = client.toOpenedFilePath(doc);
-		// if (!file) {
-		// 	return;
-		// }
-		// const args: ExperimentalProtocol.EncodedSemanticClassificationsRequestArgs = {
-		// 	file: file,
-		// 	start: 0,
-		// 	length: doc.getText().length,
-		// };
-
-		// const response = await client.execute('encodedSemanticClassifications-full', args, cancellationTokenSource.token);
-
-		// if (response.type !== 'response') {
-		// 	return;
-		// }
-		// if (!response.body) {
-		// 	return;
-		// }
-		// console.log(response.body);
-	};
-
-	vscode.window.onDidChangeActiveTextEditor(run);
-	run();
-
-	console.log(`I am running...`);
-
-	// return vscode.Disposable.from();
-	// return vscode.languages.registerRenameProvider(selector,
-	// 	new TypeScriptRenameProvider(client, fileConfigurationManager));
-
-	return vscode.languages.registerSemanticColoringProvider(selector, provider);
-	// return vscode.languages.registerSemanticColoringProvider(selector, )
+	return vscode.languages.registerSemanticColoringProvider(selector, new SemanticColoringProvider(client));
 }
diff --git a/src/vs/editor/common/core/lineTokens.ts b/src/vs/editor/common/core/lineTokens.ts
index ffc1f05f49e..51aa6a93ca8 100644
--- a/src/vs/editor/common/core/lineTokens.ts
+++ b/src/vs/editor/common/core/lineTokens.ts
@@ -67,6 +67,11 @@ export class LineTokens implements IViewLineTokens {
 		return 0;
 	}
 
+	public getMetadata(tokenIndex: number): number {
+		const metadata = this._tokens[(tokenIndex << 1) + 1];
+		return metadata;
+	}
+
 	public getLanguageId(tokenIndex: number): LanguageId {
 		const metadata = this._tokens[(tokenIndex << 1) + 1];
 		return TokenMetadata.getLanguageId(metadata);
@@ -132,8 +137,8 @@ export class LineTokens implements IViewLineTokens {
 
 		while (low < high) {
 
-			let mid = low + Math.floor((high - low) / 2);
-			let endOffset = tokens[(mid << 1)];
+			const mid = low + Math.floor((high - low) / 2);
+			const endOffset = tokens[(mid << 1)];
 
 			if (endOffset === desiredIndex) {
 				return mid + 1;
diff --git a/src/vs/editor/common/model.ts b/src/vs/editor/common/model.ts
index b73b57df96d..36189f3f378 100644
--- a/src/vs/editor/common/model.ts
+++ b/src/vs/editor/common/model.ts
@@ -14,7 +14,7 @@ import { IModelContentChange, IModelContentChangedEvent, IModelDecorationsChange
 import { SearchData } from 'vs/editor/common/model/textModelSearch';
 import { LanguageId, LanguageIdentifier, FormattingOptions } from 'vs/editor/common/modes';
 import { ThemeColor } from 'vs/platform/theme/common/themeService';
-import { MultilineTokens } from 'vs/editor/common/model/tokensStore';
+import { MultilineTokens, MultilineTokens2 } from 'vs/editor/common/model/tokensStore';
 
 /**
  * Vertical Lane in the overview ruler of the editor.
@@ -791,6 +791,11 @@ export interface ITextModel {
 	 */
 	setTokens(tokens: MultilineTokens[]): void;
 
+	/**
+	 * @internal
+	 */
+	setSemanticTokens(tokens: MultilineTokens2[]): void;
+
 	/**
 	 * Flush all tokenization state.
 	 * @internal
diff --git a/src/vs/editor/common/model/textModel.ts b/src/vs/editor/common/model/textModel.ts
index 8545d94bd51..85112a1ed67 100644
--- a/src/vs/editor/common/model/textModel.ts
+++ b/src/vs/editor/common/model/textModel.ts
@@ -32,7 +32,7 @@ import { BracketsUtils, RichEditBracket, RichEditBrackets } from 'vs/editor/comm
 import { ITheme, ThemeColor } from 'vs/platform/theme/common/themeService';
 import { withUndefinedAsNull } from 'vs/base/common/types';
 import { VSBufferReadableStream, VSBuffer } from 'vs/base/common/buffer';
-import { TokensStore, MultilineTokens, countEOL } from 'vs/editor/common/model/tokensStore';
+import { TokensStore, MultilineTokens, countEOL, MultilineTokens2, TokensStore2 } from 'vs/editor/common/model/tokensStore';
 import { Color } from 'vs/base/common/color';
 
 function createTextBufferBuilder() {
@@ -276,7 +276,7 @@ export class TextModel extends Disposable implements model.ITextModel {
 	private _languageIdentifier: LanguageIdentifier;
 	private readonly _languageRegistryListener: IDisposable;
 	private readonly _tokens: TokensStore;
-	private readonly _tokens2: TokensStore;
+	private readonly _tokens2: TokensStore2;
 	private readonly _tokenization: TextModelTokenization;
 	//#endregion
 
@@ -340,7 +340,7 @@ export class TextModel extends Disposable implements model.ITextModel {
 		this._trimAutoWhitespaceLines = null;
 
 		this._tokens = new TokensStore();
-		this._tokens2 = new TokensStore();
+		this._tokens2 = new TokensStore2();
 		this._tokenization = new TextModelTokenization(this);
 	}
 
@@ -1721,8 +1721,14 @@ export class TextModel extends Disposable implements model.ITextModel {
 		});
 	}
 
-	public setSemanticTokens(tokens: MultilineTokens[]): void {
-		
+	public setSemanticTokens(tokens: MultilineTokens2[]): void {
+		this._tokens2.set(tokens);
+
+		// TODO@semantic: could we reduce the event here?
+		this._emitModelTokensChangedEvent({
+			tokenizationSupportChanged: false,
+			ranges: [{ fromLineNumber: 1, toLineNumber: this.getLineCount() }]
+		});
 	}
 
 	public tokenizeViewport(startLineNumber: number, endLineNumber: number): void {
@@ -1785,7 +1791,8 @@ export class TextModel extends Disposable implements model.ITextModel {
 
 	private _getLineTokens(lineNumber: number): LineTokens {
 		const lineText = this.getLineContent(lineNumber);
-		return this._tokens.getTokens(this._languageIdentifier.id, lineNumber - 1, lineText);
+		const syntacticTokens = this._tokens.getTokens(this._languageIdentifier.id, lineNumber - 1, lineText);
+		return this._tokens2.addSemanticTokens(lineNumber, syntacticTokens);
 	}
 
 	public getLanguageIdentifier(): LanguageIdentifier {
diff --git a/src/vs/editor/common/model/tokensStore.ts b/src/vs/editor/common/model/tokensStore.ts
index d965bcf8937..03ebcffeb39 100644
--- a/src/vs/editor/common/model/tokensStore.ts
+++ b/src/vs/editor/common/model/tokensStore.ts
@@ -109,6 +109,205 @@ export class MultilineTokensBuilder {
 	}
 }
 
+export interface IEncodedTokens {
+	empty(): IEncodedTokens;
+	getTokenCount(): number;
+	getDeltaLine(tokenIndex: number): number;
+	getMaxDeltaLine(): number;
+	getStartCharacter(tokenIndex: number): number;
+	getEndCharacter(tokenIndex: number): number;
+	getMetadata(tokenIndex: number): number;
+
+	delete(startDeltaLine: number, startCharacter: number, endDeltaLine: number, endCharacter: number): IEncodedTokens;
+}
+
+export class SparseEncodedTokens implements IEncodedTokens {
+	/**
+	 * The encoding of tokens is:
+	 *  4*i    deltaLine (from `startLineNumber`)
+	 *  4*i+1  startCharacter (from the line start)
+	 *  4*i+2  endCharacter (from the line start)
+	 *  4*i+3  metadata
+	 */
+	private tokens: Uint32Array;
+
+	constructor(tokens: Uint32Array) {
+		this.tokens = tokens;
+	}
+
+	public empty(): IEncodedTokens {
+		return new SparseEncodedTokens(new Uint32Array(0));
+	}
+
+	public delete(startDeltaLine: number, startCharacter: number, endDeltaLine: number, endCharacter: number): IEncodedTokens {
+		throw new Error(`Not implemented`); // TODO@semantic
+	}
+
+	public getMaxDeltaLine(): number {
+		const tokenCount = this.getTokenCount();
+		if (tokenCount === 0) {
+			return -1;
+		}
+		return this.getDeltaLine(tokenCount - 1);
+	}
+
+	public getTokenCount(): number {
+		return this.tokens.length / 4;
+	}
+
+	public getDeltaLine(tokenIndex: number): number {
+		return this.tokens[4 * tokenIndex];
+	}
+
+	public getStartCharacter(tokenIndex: number): number {
+		return this.tokens[4 * tokenIndex + 1];
+	}
+
+	public getEndCharacter(tokenIndex: number): number {
+		return this.tokens[4 * tokenIndex + 2];
+	}
+
+	public getMetadata(tokenIndex: number): number {
+		return this.tokens[4 * tokenIndex + 3];
+	}
+}
+
+export class LineTokens2 {
+
+	private readonly _actual: IEncodedTokens;
+	private readonly _startTokenIndex: number;
+	private readonly _endTokenIndex: number;
+
+	constructor(actual: IEncodedTokens, startTokenIndex: number, endTokenIndex: number) {
+		this._actual = actual;
+		this._startTokenIndex = startTokenIndex;
+		this._endTokenIndex = endTokenIndex;
+	}
+
+	public getCount(): number {
+		return this._endTokenIndex - this._startTokenIndex + 1;
+	}
+
+	public getStartCharacter(tokenIndex: number): number {
+		return this._actual.getStartCharacter(this._startTokenIndex + tokenIndex);
+	}
+
+	public getEndCharacter(tokenIndex: number): number {
+		return this._actual.getEndCharacter(this._startTokenIndex + tokenIndex);
+	}
+
+	public getMetadata(tokenIndex: number): number {
+		return this._actual.getMetadata(this._startTokenIndex + tokenIndex);
+	}
+}
+
+export class MultilineTokens2 {
+
+	public startLineNumber: number;
+	public endLineNumber: number;
+	public tokens: IEncodedTokens;
+
+	constructor(startLineNumber: number, tokens: IEncodedTokens) {
+		this.startLineNumber = startLineNumber;
+		this.tokens = tokens;
+		this.endLineNumber = this.startLineNumber + this.tokens.getMaxDeltaLine();
+	}
+
+	private _setTokens(tokens: IEncodedTokens): void {
+		this.tokens = tokens;
+		this.endLineNumber = this.startLineNumber + this.tokens.getMaxDeltaLine();
+	}
+
+	public getLineTokens(lineNumber: number): LineTokens2 | null {
+		if (this.startLineNumber <= lineNumber && lineNumber <= this.endLineNumber) {
+			const findResult = MultilineTokens2._findTokensWithLine(this.tokens, lineNumber - this.startLineNumber);
+			if (findResult) {
+				const [startTokenIndex, endTokenIndex] = findResult;
+				return new LineTokens2(this.tokens, startTokenIndex, endTokenIndex);
+			}
+		}
+		return null;
+	}
+
+	private static _findTokensWithLine(tokens: IEncodedTokens, deltaLine: number): [number, number] | null {
+		let low = 0;
+		let high = tokens.getTokenCount() - 1;
+
+		while (low < high) {
+			const mid = low + Math.floor((high - low) / 2);
+			const midDeltaLine = tokens.getDeltaLine(mid);
+
+			if (midDeltaLine < deltaLine) {
+				low = mid + 1;
+			} else if (midDeltaLine > deltaLine) {
+				high = mid - 1;
+			} else {
+				let min = mid;
+				while (min > low && tokens.getDeltaLine(min - 1) === deltaLine) {
+					min--;
+				}
+				let max = mid;
+				while (max < high && tokens.getDeltaLine(max + 1) === deltaLine) {
+					max++;
+				}
+				return [min, max];
+			}
+		}
+
+		if (tokens.getDeltaLine(low) === deltaLine) {
+			return [low, low];
+		}
+
+		return null;
+	}
+
+	public applyEdit(range: IRange, text: string): void {
+		// const [eolCount, firstLineLength] = countEOL(text);
+		this._acceptDeleteRange(range);
+		// this._acceptInsertText(new Position(range.startLineNumber, range.startColumn), eolCount, firstLineLength);
+	}
+
+	private _acceptDeleteRange(range: IRange): void {
+		if (range.startLineNumber === range.endLineNumber && range.startColumn === range.endColumn) {
+			// Nothing to delete
+			return;
+		}
+
+		const firstLineIndex = range.startLineNumber - this.startLineNumber;
+		const lastLineIndex = range.endLineNumber - this.startLineNumber;
+
+		if (lastLineIndex < 0) {
+			// this deletion occurs entirely before this block, so we only need to adjust line numbers
+			const deletedLinesCount = lastLineIndex - firstLineIndex;
+			this.startLineNumber -= deletedLinesCount;
+			return;
+		}
+
+		const tokenMaxDeltaLine = this.tokens.getMaxDeltaLine();
+
+		if (firstLineIndex >= tokenMaxDeltaLine + 1) {
+			// this deletion occurs entirely after this block, so there is nothing to do
+			return;
+		}
+
+		if (firstLineIndex < 0 && lastLineIndex >= tokenMaxDeltaLine + 1) {
+			// this deletion completely encompasses this block
+			this.startLineNumber = 0;
+			this._setTokens(this.tokens.empty());
+			return;
+		}
+
+		if (firstLineIndex < 0) {
+			const deletedBefore = -firstLineIndex;
+			this.startLineNumber -= deletedBefore;
+
+			this._setTokens(this.tokens.delete(0, 0, lastLineIndex, range.endColumn - 1));
+		} else {
+			this._setTokens(this.tokens.delete(firstLineIndex, range.startColumn - 1, lastLineIndex, range.endColumn - 1));
+		}
+	}
+}
+
 export class MultilineTokens {
 
 	public startLineNumber: number;
@@ -193,6 +392,7 @@ export class MultilineTokens {
 			// this deletion completely encompasses this block
 			this.startLineNumber = 0;
 			this.tokens = [];
+			return;
 		}
 
 		if (firstLineIndex === lastLineIndex) {
@@ -289,6 +489,130 @@ function toUint32Array(arr: Uint32Array | ArrayBuffer): Uint32Array {
 	}
 }
 
+export class TokensStore2 {
+
+	private _pieces: MultilineTokens2[];
+
+	constructor() {
+		this._pieces = [];
+	}
+
+	public flush(): void {
+		this._pieces = [];
+	}
+
+	public set(pieces: MultilineTokens2[]) {
+		this._pieces = pieces;
+	}
+
+	public addSemanticTokens(lineNumber: number, aTokens: LineTokens): LineTokens {
+		const pieces = this._pieces;
+
+		if (pieces.length === 0) {
+			return aTokens;
+		}
+
+		const pieceIndex = TokensStore2._findFirstPieceWithLine(pieces, lineNumber);
+		const bTokens = this._pieces[pieceIndex].getLineTokens(lineNumber);
+
+		if (!bTokens) {
+			return aTokens;
+		}
+
+		const aLen = aTokens.getCount();
+		const bLen = bTokens.getCount();
+
+		let aIndex = 0;
+		let result: number[] = [], resultLen = 0;
+		for (let bIndex = 0; bIndex < bLen; bIndex++) {
+			const bStartCharacter = bTokens.getStartCharacter(bIndex);
+			const bEndCharacter = bTokens.getEndCharacter(bIndex);
+			const bMetadata = bTokens.getMetadata(bIndex); // TODO@semantic: should use languageId from aTokens :/ :/ :/
+
+			// push any token from `a` that is before `b`
+			while (aIndex < aLen && aTokens.getEndOffset(aIndex) <= bStartCharacter) {
+				result[resultLen++] = aTokens.getEndOffset(aIndex);
+				result[resultLen++] = aTokens.getMetadata(aIndex);
+				aIndex++;
+			}
+
+			// push the token from `a` if it intersects the token from `b`
+			if (aIndex < aLen && aTokens.getStartOffset(aIndex) < bStartCharacter) {
+				result[resultLen++] = bStartCharacter;
+				result[resultLen++] = aTokens.getMetadata(aIndex);
+			}
+
+			// skip any tokens from `a` that are contained inside `b`
+			while (aIndex < aLen && aTokens.getEndOffset(aIndex) <= bEndCharacter) {
+				aIndex++;
+			}
+
+			// push the token from `b`
+			result[resultLen++] = bEndCharacter;
+			result[resultLen++] = bMetadata;
+		}
+
+		// push the remaining tokens from `a`
+		while (aIndex < aLen) {
+			result[resultLen++] = aTokens.getEndOffset(aIndex);
+			result[resultLen++] = aTokens.getMetadata(aIndex);
+			aIndex++;
+		}
+
+		return new LineTokens(new Uint32Array(result), aTokens.getLineContent());
+
+		console.log(result);
+
+		// let currentMetadata = 0;
+
+
+
+
+		// const len = pieces.length;
+		// while (pieceIndex < len) {
+		// }
+		console.log(`addSemanticTokens for ${lineNumber}`);
+		console.log(bTokens);
+
+		// console.log(`pieceIndex: ${pieceIndex}`);
+		return aTokens;
+	}
+
+	// private static _findLine(piece: Multiline)
+
+	private static _findFirstPieceWithLine(pieces: MultilineTokens2[], lineNumber: number): number {
+		let low = 0;
+		let high = pieces.length - 1;
+
+		while (low < high) {
+			let mid = low + Math.floor((high - low) / 2);
+
+			if (pieces[mid].endLineNumber < lineNumber) {
+				low = mid + 1;
+			} else if (pieces[mid].startLineNumber > lineNumber) {
+				high = mid - 1;
+			} else {
+				while (mid > low && pieces[mid - 1].startLineNumber <= lineNumber && lineNumber <= pieces[mid - 1].endLineNumber) {
+					mid--;
+				}
+				return mid;
+			}
+		}
+
+		return low;
+	}
+
+	//#region Editing
+
+	public acceptEdit(range: IRange, eolCount: number, firstLineLength: number): void {
+		console.log(`TODO@semantic --> acceptEdit !!!!`);
+		// this._acceptDeleteRange(range);
+		// this._acceptInsertText(new Position(range.startLineNumber, range.startColumn), eolCount, firstLineLength);
+	}
+
+	//#endregion
+}
+
 export class TokensStore {
 	private _lineTokens: (Uint32Array | ArrayBuffer | null)[];
 	private _len: number;
diff --git a/src/vs/editor/common/services/modelServiceImpl.ts b/src/vs/editor/common/services/modelServiceImpl.ts
index f7788996ded..8850feb404a 100644
--- a/src/vs/editor/common/services/modelServiceImpl.ts
+++ b/src/vs/editor/common/services/modelServiceImpl.ts
@@ -22,6 +22,7 @@ import { ITextResourcePropertiesService } from 'vs/editor/common/services/resour
 import { IConfigurationService } from 'vs/platform/configuration/common/configuration';
 import { RunOnceScheduler } from 'vs/base/common/async';
 import { CancellationTokenSource } from 'vs/base/common/cancellation';
+import { SparseEncodedTokens, MultilineTokens2 } from 'vs/editor/common/model/tokensStore';
 
 function MODEL_ID(resource: URI): string {
 	return resource.toString();
@@ -524,17 +525,21 @@ class ModelSemanticColoring extends Disposable {
 		}
 		this._currentResponse = tokens;
 		// TODO@semantic: diff here and reduce to only really needed tokens...
+		// TODO@semantic: might also be a good idea to split areas... ?
 		if (this._currentResponse) {
+			const result: MultilineTokens2[] = [];
 			for (const area of this._currentResponse.areas) {
-				const tokenCount = area.data.length / 5;
-				const tokens = new Uint32Array(2 * tokenCount);
+				const srcTokens = area.data;
+				const tokenCount = srcTokens.length / 5;
+				const destTokens = new Uint32Array(4 * tokenCount);
 				for (let i = 0; i < tokenCount; i++) {
-					const offset = 5 * i;
-					const deltaLine = area.data[offset];
-					const startCharacter = area.data[offset + 1];
-					const endCharacter = area.data[offset + 2];
-					const tokenType = area.data[offset + 3];
-					const tokenModifiers = area.data[offset + 4];
+					const srcOffset = 5 * i;
+					const deltaLine = srcTokens[srcOffset];
+					const startCharacter = srcTokens[srcOffset + 1];
+					const endCharacter = srcTokens[srcOffset + 2];
+					// const tokenType = srcTokens[srcOffset + 3];
+					// const tokenModifiers = srcTokens[srcOffset + 4];
+					// TODO@semantic: map here tokenType and tokenModifiers to metadata
 
 					const fontStyle = FontStyle.Italic | FontStyle.Bold | FontStyle.Underline;
 					const foregroundColorId = 3;
@@ -542,12 +547,21 @@ class ModelSemanticColoring extends Disposable {
 						(fontStyle << MetadataConsts.FONT_STYLE_OFFSET)
 						| (foregroundColorId << MetadataConsts.FOREGROUND_OFFSET)
 					) >>> 0;
-					// tokens[2 * i] =
+
+					const destOffset = 4 * i;
+					destTokens[destOffset] = deltaLine;
+					destTokens[destOffset + 1] = startCharacter;
+					destTokens[destOffset + 2] = endCharacter;
+					destTokens[destOffset + 3] = metadata;
 				}
+
+				const tokens = new MultilineTokens2(area.line, new SparseEncodedTokens(destTokens));
+				result.push(tokens);
 			}
-			console.log(`_setSemanticTokens`, tokens);
-			// Convert this into editor friendly tokens
-			// for (let )
+
+			this._model.setSemanticTokens(result);
+		} else {
+			// TODO@semantic: should we clear semantic tokens on the text model here?
 		}
 	}
 
diff --git a/src/vs/workbench/api/common/extHostLanguageFeatures.ts b/src/vs/workbench/api/common/extHostLanguageFeatures.ts
index 9d0780b5de0..9c656fdd44d 100644
--- a/src/vs/workbench/api/common/extHostLanguageFeatures.ts
+++ b/src/vs/workbench/api/common/extHostLanguageFeatures.ts
@@ -27,7 +27,7 @@ import { ExtensionIdentifier, IExtensionDescription } from 'vs/platform/extensio
 import { IURITransformer } from 'vs/base/common/uriIpc';
 import { DisposableStore, dispose } from 'vs/base/common/lifecycle';
 import { VSBuffer } from 'vs/base/common/buffer';
-import { encodeSemanticTokensDto, ISemanticTokensFullAreaDto, ISemanticTokensDto } from 'vs/workbench/api/common/shared/semanticTokens';
+import { encodeSemanticTokensDto, ISemanticTokensDto } from 'vs/workbench/api/common/shared/semanticTokens';
 
 // --- adapter
 
@@ -665,8 +665,8 @@ class SemanticColoringAdapter {
 		return r;
 	}
 
-	releaseSemanticColoring(semanticColoringResultId: number): Promise<void> {
-	}
+	// releaseSemanticColoring(semanticColoringResultId: number): Promise<void> {
+	// }
 
 	// provideSignatureHelp(resource: URI, token: CancellationToken): Promise<extHostProtocol.ISignatureHelpDto | undefined> {
 	// 	const doc = this._documents.getDocument(resource);
diff --git a/src/vs/workbench/api/common/shared/semanticTokens.ts b/src/vs/workbench/api/common/shared/semanticTokens.ts
index 294067aeac8..168da4c795b 100644
--- a/src/vs/workbench/api/common/shared/semanticTokens.ts
+++ b/src/vs/workbench/api/common/shared/semanticTokens.ts
@@ -64,10 +64,21 @@ export function decodeSemanticTokensDto(buff: VSBuffer): ISemanticTokensDto {
 
 function encodeArea(area: ISemanticTokensFullAreaDto | ISemanticTokensDeltaAreaDto, buff: VSBuffer, offset: number): number {
 	buff.writeUInt8(area.type === 'full' ? EncodedSemanticTokensAreaType.Full : EncodedSemanticTokensAreaType.Delta, offset); offset += 1;
-	buff.writeUInt32BE(area.line, offset); offset += 4;
+	buff.writeUInt32BE(area.line + 1, offset); offset += 4;
 	if (area.type === 'full') {
-		buff.writeUInt32BE(area.data.byteLength, offset); offset += 4;
-		buff.set(VSBuffer.wrap(area.data), offset); offset += area.data.byteLength;
+		const tokens = area.data;
+		const tokenCount = (tokens.length / 5) | 0;
+		buff.writeUInt32BE(tokenCount, offset); offset += 4;
+		// here we are explicitly iterating an writing the ints again to ensure writing the desired endianness.
+		for (let i = 0; i < tokenCount; i++) {
+			const tokenOffset = 5 * i;
+			buff.writeUInt32BE(tokens[tokenOffset], offset); offset += 4;
+			buff.writeUInt32BE(tokens[tokenOffset + 1], offset); offset += 4;
+			buff.writeUInt32BE(tokens[tokenOffset + 2], offset); offset += 4;
+			buff.writeUInt32BE(tokens[tokenOffset + 3], offset); offset += 4;
+			buff.writeUInt32BE(tokens[tokenOffset + 4], offset); offset += 4;
+		}
+		// buff.set(VSBuffer.wrap(uint8), offset); offset += area.data.byteLength;
 	} else {
 		buff.writeUInt32BE(area.oldIndex, offset); offset += 4;
 	}
@@ -79,8 +90,10 @@ function encodedAreaSize(area: ISemanticTokensFullAreaDto | ISemanticTokensDelta
 	result += 1; // type
 	result += 4; // line
 	if (area.type === 'full') {
-		result += 4; // data byte length
-		result += area.data.byteLength;
+		const tokens = area.data;
+		const tokenCount = (tokens.length / 5) | 0;
+		result += 4; // token count
+		result += tokenCount * 5 * 4;
 		return result;
 	} else {
 		result += 4; // old index
@@ -92,15 +105,21 @@ function decodeArea(buff: VSBuffer, offset: number, areas: (ISemanticTokensFullA
 	const type: EncodedSemanticTokensAreaType = buff.readUInt8(offset); offset += 1;
 	const line = buff.readUInt32BE(offset); offset += 4;
 	if (type === EncodedSemanticTokensAreaType.Full) {
-		const dataByteLength = buff.readUInt32BE(offset); offset += 4;
-		const data = buff.slice(offset, offset + dataByteLength); offset += dataByteLength;
-		const buffer = data.buffer;
-		const bufferByteOffset = buffer.byteOffset;
-		const bufferByteLength = buffer.byteLength;
+		// here we are explicitly iterating and reading the ints again to ensure reading the desired endianness.
+		const tokenCount = buff.readUInt32BE(offset); offset += 4;
+		const data = new Uint32Array(5 * tokenCount);
+		for (let i = 0; i < tokenCount; i++) {
+			const destOffset = 5 * i;
+			data[destOffset] = buff.readUInt32BE(offset); offset += 4;
+			data[destOffset + 1] = buff.readUInt32BE(offset); offset += 4;
+			data[destOffset + 2] = buff.readUInt32BE(offset); offset += 4;
+			data[destOffset + 3] = buff.readUInt32BE(offset); offset += 4;
+			data[destOffset + 4] = buff.readUInt32BE(offset); offset += 4;
+		}
 		areas.push({
 			type: 'full',
 			line: line,
-			data: new Uint32Array(buffer, bufferByteOffset, bufferByteLength / 4)
+			data: data
 		});
 		return offset;
 	} else {