diff --git a/.serena/cache/typescript/document_symbols_cache_v23-06-25.pkl b/.serena/cache/typescript/document_symbols_cache_v23-06-25.pkl
index b6ffaf6..915f1b1 100644
Binary files a/.serena/cache/typescript/document_symbols_cache_v23-06-25.pkl and b/.serena/cache/typescript/document_symbols_cache_v23-06-25.pkl differ
diff --git a/changelog.md b/changelog.md
index ce83c42..dacee22 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,15 @@
 # Changelog
 
+## 2025-08-18 - 4.2.1 - fix(gzip)
+Improve gzip streaming decompression, archive analysis and unpacking; add gzip tests
+
+- Add a streaming DecompressGunzipTransform using fflate.Gunzip with proper _flush handling to support chunked gzip input and avoid buffering issues.
+- Refactor ArchiveAnalyzer: introduce IAnalyzedResult, getAnalyzedStream(), and getDecompressionStream() to better detect mime types and wire appropriate decompression streams (gzip, zip, bzip2, tar).
+- Use SmartRequest response streams converted via stream.Readable.fromWeb for URL sources in SmartArchive.getArchiveStream() to improve remote archive handling.
+- Improve nested archive unpacking and SmartArchive export pipeline: more robust tar/zip handling, consistent SmartDuplex usage and backpressure handling.
+- Enhance exportToFs: ensure directories, improved logging for relative paths, and safer write-stream wiring.
+- Add comprehensive gzip-focused tests (test/test.gzip.ts) covering file extraction, stream extraction, header filename handling, large files, and a real-world tgz-from-URL extraction scenario.
+
 ## 2025-08-18 - 4.2.0 - feat(classes.smartarchive)
 Support URL streams, recursive archive unpacking and filesystem export; improve ZIP/GZIP/BZIP2 robustness; CI and package metadata updates
 
diff --git a/test/test.gzip.ts b/test/test.gzip.ts
new file mode 100644
index 0000000..451a289
--- /dev/null
+++ b/test/test.gzip.ts
@@ -0,0 +1,219 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import * as plugins from './plugins.js';
+import * as smartarchive from '../ts/index.js';
+
+const testPaths = {
+  nogitDir: plugins.path.join(
+    plugins.smartpath.get.dirnameFromImportMetaUrl(import.meta.url),
+    '../.nogit/',
+  ),
+  gzipTestDir: plugins.path.join(
+    plugins.smartpath.get.dirnameFromImportMetaUrl(import.meta.url),
+    '../.nogit/gzip-test',
+  ),
+};
+
+tap.preTask('should prepare test directories', async () => {
+  await plugins.smartfile.fs.ensureDir(testPaths.gzipTestDir);
+});
+
+tap.test('should create and extract a gzip file', async () => {
+  // Create test data
+  const testContent = 'This is a test file for gzip compression and decompression.\n'.repeat(100);
+  const testFileName = 'test-file.txt';
+  const gzipFileName = 'test-file.txt.gz';
+  
+  // Write the original file
+  await plugins.smartfile.memory.toFs(
+    testContent,
+    plugins.path.join(testPaths.gzipTestDir, testFileName)
+  );
+  
+  // Compress the file using gzip
+  const originalFile = await plugins.smartfile.fs.fileTreeToObject(
+    testPaths.gzipTestDir,
+    testFileName
+  );
+  
+  // Create gzip compressed version using fflate directly
+  const fflate = await import('fflate');
+  const compressed = fflate.gzipSync(Buffer.from(testContent));
+  await plugins.smartfile.memory.toFs(
+    Buffer.from(compressed),
+    plugins.path.join(testPaths.gzipTestDir, gzipFileName)
+  );
+  
+  // Now test extraction using SmartArchive
+  const gzipArchive = await smartarchive.SmartArchive.fromArchiveFile(
+    plugins.path.join(testPaths.gzipTestDir, gzipFileName)
+  );
+  
+  // Export to a new location
+  const extractPath = plugins.path.join(testPaths.gzipTestDir, 'extracted');
+  await plugins.smartfile.fs.ensureDir(extractPath);
+  // Provide a filename since gzip doesn't contain filename metadata
+  await gzipArchive.exportToFs(extractPath, 'test-file.txt');
+  
+  // Read the extracted file
+  const extractedContent = await plugins.smartfile.fs.toStringSync(
+    plugins.path.join(extractPath, 'test-file.txt')
+  );
+  
+  // Verify the content matches
+  expect(extractedContent).toEqual(testContent);
+});
+
+tap.test('should handle gzip stream extraction', async () => {
+  // Create test data
+  const testContent = 'Stream test data for gzip\n'.repeat(50);
+  const gzipFileName = 'stream-test.txt.gz';
+  
+  // Create gzip compressed version
+  const fflate = await import('fflate');
+  const compressed = fflate.gzipSync(Buffer.from(testContent));
+  await plugins.smartfile.memory.toFs(
+    Buffer.from(compressed),
+    plugins.path.join(testPaths.gzipTestDir, gzipFileName)
+  );
+  
+  // Create a read stream for the gzip file
+  const gzipStream = plugins.smartfile.fsStream.createReadStream(
+    plugins.path.join(testPaths.gzipTestDir, gzipFileName)
+  );
+  
+  // Test extraction using SmartArchive from stream
+  const gzipArchive = await smartarchive.SmartArchive.fromArchiveStream(gzipStream);
+  
+  // Export to stream and collect the result
+  const streamFiles: any[] = [];
+  const resultStream = await gzipArchive.exportToStreamOfStreamFiles();
+  
+  await new Promise<void>((resolve, reject) => {
+    resultStream.on('data', (streamFile) => {
+      streamFiles.push(streamFile);
+    });
+    resultStream.on('end', resolve);
+    resultStream.on('error', reject);
+  });
+  
+  // Verify we got the expected file
+  expect(streamFiles.length).toBeGreaterThan(0);
+  
+  // Read content from the stream file
+  if (streamFiles[0]) {
+    const chunks: Buffer[] = [];
+    const readStream = await streamFiles[0].createReadStream();
+    await new Promise<void>((resolve, reject) => {
+      readStream.on('data', (chunk: Buffer) => chunks.push(chunk));
+      readStream.on('end', resolve);
+      readStream.on('error', reject);
+    });
+    
+    const extractedContent = Buffer.concat(chunks).toString();
+    expect(extractedContent).toEqual(testContent);
+  }
+});
+
+tap.test('should handle gzip files with original filename in header', async () => {
+  // Test with a real-world gzip file that includes filename in header
+  const testContent = 'File with name in gzip header\n'.repeat(30);
+  const originalFileName = 'original-name.log';
+  const gzipFileName = 'compressed.gz';
+  
+  // Create a proper gzip with filename header using Node's zlib
+  const zlib = await import('zlib');
+  const gzipBuffer = await new Promise<Buffer>((resolve, reject) => {
+    zlib.gzip(Buffer.from(testContent), { 
+      level: 9,
+      // Note: Node's zlib doesn't support embedding filename directly,
+      // but we can test the extraction anyway
+    }, (err, result) => {
+      if (err) reject(err);
+      else resolve(result);
+    });
+  });
+  
+  await plugins.smartfile.memory.toFs(
+    gzipBuffer,
+    plugins.path.join(testPaths.gzipTestDir, gzipFileName)
+  );
+  
+  // Test extraction
+  const gzipArchive = await smartarchive.SmartArchive.fromArchiveFile(
+    plugins.path.join(testPaths.gzipTestDir, gzipFileName)
+  );
+  
+  const extractPath = plugins.path.join(testPaths.gzipTestDir, 'header-test');
+  await plugins.smartfile.fs.ensureDir(extractPath);
+  // Provide a filename since gzip doesn't reliably contain filename metadata
+  await gzipArchive.exportToFs(extractPath, 'compressed.txt');
+  
+  // Check if file was extracted (name might be derived from archive name)
+  const files = await plugins.smartfile.fs.listFileTree(extractPath, '**/*');
+  expect(files.length).toBeGreaterThan(0);
+  
+  // Read and verify content
+  const extractedFile = files[0];
+  const extractedContent = await plugins.smartfile.fs.toStringSync(
+    plugins.path.join(extractPath, extractedFile || 'compressed.txt')
+  );
+  expect(extractedContent).toEqual(testContent);
+});
+
+tap.test('should handle large gzip files', async () => {
+  // Create a larger test file
+  const largeContent = 'x'.repeat(1024 * 1024); // 1MB of 'x' characters
+  const gzipFileName = 'large-file.txt.gz';
+  
+  // Compress the large file
+  const fflate = await import('fflate');
+  const compressed = fflate.gzipSync(Buffer.from(largeContent));
+  await plugins.smartfile.memory.toFs(
+    Buffer.from(compressed),
+    plugins.path.join(testPaths.gzipTestDir, gzipFileName)
+  );
+  
+  // Test extraction
+  const gzipArchive = await smartarchive.SmartArchive.fromArchiveFile(
+    plugins.path.join(testPaths.gzipTestDir, gzipFileName)
+  );
+  
+  const extractPath = plugins.path.join(testPaths.gzipTestDir, 'large-extracted');
+  await plugins.smartfile.fs.ensureDir(extractPath);
+  // Provide a filename since gzip doesn't contain filename metadata
+  await gzipArchive.exportToFs(extractPath, 'large-file.txt');
+  
+  // Verify the extracted content
+  const files = await plugins.smartfile.fs.listFileTree(extractPath, '**/*');
+  expect(files.length).toBeGreaterThan(0);
+  
+  const extractedContent = await plugins.smartfile.fs.toStringSync(
+    plugins.path.join(extractPath, files[0] || 'large-file.txt')
+  );
+  expect(extractedContent.length).toEqual(largeContent.length);
+  expect(extractedContent).toEqual(largeContent);
+});
+
+tap.test('should handle real-world multi-chunk gzip from URL', async () => {
+  // Test with a real tgz file that will be processed in multiple chunks
+  const testUrl = 'https://registry.npmjs.org/@push.rocks/smartfile/-/smartfile-11.2.7.tgz';
+  
+  // Download and extract the archive
+  const testArchive = await smartarchive.SmartArchive.fromArchiveUrl(testUrl);
+  
+  const extractPath = plugins.path.join(testPaths.gzipTestDir, 'real-world-test');
+  await plugins.smartfile.fs.ensureDir(extractPath);
+  
+  // This will test multi-chunk decompression as the file is larger
+  await testArchive.exportToFs(extractPath);
+  
+  // Verify extraction worked
+  const files = await plugins.smartfile.fs.listFileTree(extractPath, '**/*');
+  expect(files.length).toBeGreaterThan(0);
+  
+  // Check for expected package structure
+  const hasPackageJson = files.some(f => f.includes('package.json'));
+  expect(hasPackageJson).toBeTrue();
+});
+
+export default tap.start();
\ No newline at end of file
diff --git a/ts/00_commitinfo_data.ts b/ts/00_commitinfo_data.ts
index 4e5e428..f23ee2d 100644
--- a/ts/00_commitinfo_data.ts
+++ b/ts/00_commitinfo_data.ts
@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartarchive',
-  version: '4.2.0',
+  version: '4.2.1',
   description: 'A library for working with archive files, providing utilities for compressing and decompressing data.'
 }
diff --git a/ts/classes.gziptools.ts b/ts/classes.gziptools.ts
index 528d901..a598f78 100644
--- a/ts/classes.gziptools.ts
+++ b/ts/classes.gziptools.ts
@@ -26,8 +26,20 @@ export class CompressGunzipTransform extends plugins.stream.Transform {
 // DecompressGunzipTransform class that extends the Node.js Transform stream to
 // create a stream that decompresses GZip-compressed data using fflate's gunzip function
 export class DecompressGunzipTransform extends plugins.stream.Transform {
+  private gunzip: any; // fflate.Gunzip instance
+  
   constructor() {
     super();
+    
+    // Create a streaming Gunzip decompressor
+    this.gunzip = new plugins.fflate.Gunzip((chunk, final) => {
+      // Push decompressed chunks to the output stream
+      this.push(Buffer.from(chunk));
+      if (final) {
+        // Signal end of stream when decompression is complete
+        this.push(null);
+      }
+    });
   }
 
   _transform(
@@ -35,17 +47,23 @@ export class DecompressGunzipTransform extends plugins.stream.Transform {
     encoding: BufferEncoding,
     callback: plugins.stream.TransformCallback,
   ) {
-    // Use fflate's gunzip function to decompress the chunk
-    plugins.fflate.gunzip(chunk, (err, decompressed) => {
-      if (err) {
-        // If an error occurs during decompression, pass the error to the callback
-        callback(err);
-      } else {
-        // If decompression is successful, push the decompressed data into the stream
-        this.push(decompressed);
-        callback();
-      }
-    });
+    try {
+      // Feed chunks to the gunzip stream
+      this.gunzip.push(chunk, false);
+      callback();
+    } catch (err) {
+      callback(err as Error);
+    }
+  }
+  
+  _flush(callback: plugins.stream.TransformCallback) {
+    try {
+      // Signal end of input to gunzip
+      this.gunzip.push(new Uint8Array(0), true);
+      callback();
+    } catch (err) {
+      callback(err as Error);
+    }
   }
 }