Repository: ResearchObject/ro-crate-py

Issue:
Support streaming for crate output
## The issue
Currently, ro-crate-py only supports writing the output directly to disk when written as zip file with `crate.write_zip("exp_crate.zip")`.

This comes with a limitation when using the library as part of a web service that creates RO-Crates on the fly and serve them as a download. In such a scenario, where files are likely not stored locally, but are stored else where (think of a database, cloud storage, ..), you generally want to stream the files from their remote location directly to the user. If you cant stream them, the need to fit into memory or you have to cache them to your hard drive to stream them from there. Both are not optimal solutions because they require you to either have a lot of memory, or a lot of disk space depending on the size of the dataset.

Zip files in general already support streaming. It would be nice if ro-crate-py would also be able to stream it's output into a stream object like io.BytesIO. This would make it compatible  HTTP Streaming.

## Example
If you follow the link below, there is a code example where I worked around this issue.

In the given example, the RO-Crates become quite large (TBytes). The generated zip would therefore never fit into the servers memory, or even on the hard drive. As a workaround, I use this library to build a crate object without actually downloading the files. I then create a zip stream where I add the written metadata file. Finally, I add all data files manually to the stream and serve it to the user as `StreamingHttpResponse`.

https://github.com/dnlbauer/FAIR-workflow-platform-frontend/blob/5900dd331b6beeb7c4ca6e8ba6c1007247b05b16/cwr_frontend/cwr_frontend/views/DatasetDetailView.py#L168

Hints from issue comments:
@simleo: I have no experience on this matter. I think it would be best if you opened a PR with the desired changes and related tests.

Solution patch:
diff --git a/CITATION.cff b/CITATION.cff
index b6bfb95f..e2e64b23 100644
--- a/CITATION.cff
+++ b/CITATION.cff
@@ -1,6 +1,9 @@
 cff-version: 1.1.0
 message: "Cite as"
-authors:
+author:
+  - family-names: Bauer
+    given-names: Daniel
+    orcid: https://orcid.org/0000-0001-9447-460X
   - family-names: Chadwick
     given-names: Eli
     orcid: https://orcid.org/0000-0002-0035-6475
diff --git a/README.md b/README.md
index ed67a13b..50488e96 100644
--- a/README.md
+++ b/README.md
@@ -451,6 +451,7 @@ Options:
 * Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 * Copyright 2024 Data Centre, SciLifeLab, SE
 * Copyright 2024 National Institute of Informatics (NII), JP
+* Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 
 Licensed under the
 Apache License, version 2.0 <https://www.apache.org/licenses/LICENSE-2.0>,
diff --git a/examples/fastapi/main.py b/examples/fastapi/main.py
new file mode 100644
index 00000000..a5c5ea57
--- /dev/null
+++ b/examples/fastapi/main.py
@@ -0,0 +1,64 @@
+# Copyright 2019-2024 The University of Manchester, UK
+# Copyright 2020-2024 Vlaams Instituut voor Biotechnologie (VIB), BE
+# Copyright 2020-2024 Barcelona Supercomputing Center (BSC), ES
+# Copyright 2020-2024 Center for Advanced Studies, Research and Development in Sardinia (CRS4), IT
+# Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
+# Copyright 2024 Data Centre, SciLifeLab, SE
+# Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Streaming RO-Crates from a web server
+
+This example demonstrates how to create an RO-Crate on-the-fly
+and stream the result to the client.
+By using `stream_zip`, the RO-Crate is not written to disk and remote
+data is only fetched on the fly.
+
+To run: `fastapi dev main.py`, then visit http://localhost:8000/crate
+"""
+
+from fastapi import FastAPI
+from fastapi.responses import StreamingResponse
+from rocrate.rocrate import ROCrate
+from io import StringIO
+
+app = FastAPI()
+
+
+@app.get("/crate")
+async def get():
+    crate = ROCrate()
+
+    # Add a remote file
+    crate.add_file(
+        "https://raw.githubusercontent.com/ResearchObject/ro-crate-py/refs/heads/master/test/test-data/sample_file.txt",
+        fetch_remote=True
+    )
+
+    # Add a file containing a string to the crate
+    crate.add_file(
+        source=StringIO("Hello, World!"),
+        dest_path="test-data/hello.txt"
+    )
+
+    # Stream crate to client as a zip file
+    return StreamingResponse(
+        crate.stream_zip(),
+        media_type="application/rocrate+zip",
+        headers={
+            "Content-Disposition": "attachment; filename=crate.zip",
+        }
+    )
diff --git a/examples/fastapi/requirements.txt b/examples/fastapi/requirements.txt
new file mode 100644
index 00000000..09eae111
--- /dev/null
+++ b/examples/fastapi/requirements.txt
@@ -0,0 +1,3 @@
+../../
+fastapi
+fastapi-cli
diff --git a/rocrate/__init__.py b/rocrate/__init__.py
index b4ef8599..53905bd9 100644
--- a/rocrate/__init__.py
+++ b/rocrate/__init__.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -30,6 +31,7 @@
 """
 
 __author__ = ", ".join((
+    'Daniel Bauer',
     'Eli Chadwick',
     'Paul De Geest',
     'Bert Droesbeke',
@@ -52,6 +54,7 @@
 Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 Copyright 2024 Data Centre, SciLifeLab, SE
 Copyright 2024 National Institute of Informatics (NII), JP
+Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 """
 __license__ = ("Apache License, version 2.0 "
                "<https://www.apache.org/licenses/LICENSE-2.0>")
diff --git a/rocrate/cli.py b/rocrate/cli.py
index a042dbd9..64693906 100644
--- a/rocrate/cli.py
+++ b/rocrate/cli.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/memory_buffer.py b/rocrate/memory_buffer.py
new file mode 100644
index 00000000..9ed5b789
--- /dev/null
+++ b/rocrate/memory_buffer.py
@@ -0,0 +1,52 @@
+# Copyright 2019-2024 The University of Manchester, UK
+# Copyright 2020-2024 Vlaams Instituut voor Biotechnologie (VIB), BE
+# Copyright 2020-2024 Barcelona Supercomputing Center (BSC), ES
+# Copyright 2020-2024 Center for Advanced Studies, Research and Development in Sardinia (CRS4), IT
+# Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
+# Copyright 2024 Data Centre, SciLifeLab, SE
+# Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from io import RawIOBase
+
+
+class MemoryBuffer(RawIOBase):
+    """
+    A buffer class that supports reading and writing binary data.
+    The buffer automatically resets upon reading to make sure all data is read only once.
+    """
+
+    def __init__(self):
+        self._buffer = b''
+
+    def write(self, data):
+        if self.closed:
+            raise ValueError('write to closed file')
+        self._buffer += data
+        return len(data)
+
+    def read(self, size=-1):
+        if self.closed:
+            raise ValueError('read from closed file')
+        if size < 0:
+            data = self._buffer
+            self._buffer = b''
+        else:
+            data = self._buffer[:size]
+            self._buffer = self._buffer[size:]
+        return data
+
+    def __len__(self):
+        return len(self._buffer)
diff --git a/rocrate/metadata.py b/rocrate/metadata.py
index 29cdb218..7a5ea720 100644
--- a/rocrate/metadata.py
+++ b/rocrate/metadata.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/__init__.py b/rocrate/model/__init__.py
index 5ae3c862..2c482d59 100644
--- a/rocrate/model/__init__.py
+++ b/rocrate/model/__init__.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/computationalworkflow.py b/rocrate/model/computationalworkflow.py
index 1ca93773..6754583e 100644
--- a/rocrate/model/computationalworkflow.py
+++ b/rocrate/model/computationalworkflow.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/computerlanguage.py b/rocrate/model/computerlanguage.py
index 88546f97..511c53ce 100644
--- a/rocrate/model/computerlanguage.py
+++ b/rocrate/model/computerlanguage.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/contextentity.py b/rocrate/model/contextentity.py
index 9ccc2fb9..1bd94db8 100644
--- a/rocrate/model/contextentity.py
+++ b/rocrate/model/contextentity.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/creativework.py b/rocrate/model/creativework.py
index 32e4341d..1b1b2498 100644
--- a/rocrate/model/creativework.py
+++ b/rocrate/model/creativework.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/data_entity.py b/rocrate/model/data_entity.py
index 22e2f01e..2c44e5ab 100644
--- a/rocrate/model/data_entity.py
+++ b/rocrate/model/data_entity.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -28,3 +29,14 @@ class DataEntity(Entity):
 
     def write(self, base_path):
         pass
+
+    def stream(self, chunk_size=8192):
+        """ Stream the data from the source. Each chunk of the content is yielded as a tuple
+        containing the name of the destination file relative to the crate and the chunk of data.
+        The destination file name is required because a DataEntity can be a file or a
+        collection of files (Dataset) and the caller need to know to which file a chunk belongs.
+        For collection of files, the caller can assume that files are streamed one after another,
+        meaning once the destination name changes, a file can be closed and the next one can be
+        openend.
+        """
+        yield from ()
diff --git a/rocrate/model/dataset.py b/rocrate/model/dataset.py
index 0e0e52ff..77f4f93c 100644
--- a/rocrate/model/dataset.py
+++ b/rocrate/model/dataset.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -22,7 +23,7 @@
 
 import errno
 import os
-import shutil
+import warnings
 from pathlib import Path
 from urllib.request import urlopen
 
@@ -43,37 +44,84 @@ def _empty(self):
     def format_id(self, identifier):
         return identifier.rstrip("/") + "/"
 
+    def _write_from_url(self, base_path):
+        if self.validate_url and not self.fetch_remote:
+            with urlopen(self.source) as _:
+                self._jsonld['sdDatePublished'] = iso_now()
+        if self.fetch_remote:
+            out_file_path, out_file = None, None
+            for rel_path, chunk in self._stream_folder_from_url():
+                path = base_path / rel_path
+                if path != out_file_path:
+                    if out_file:
+                        out_file.close()
+                    out_file_path = Path(path)
+                    out_file_path.parent.mkdir(parents=True, exist_ok=True)
+                    out_file = open(out_file_path, 'wb')
+                out_file.write(chunk)
+            if out_file:
+                out_file.close()
+
+    def _copy_folder(self, base_path):
+        abs_out_path = base_path / self.id
+        if self.source is None:
+            abs_out_path.mkdir(parents=True, exist_ok=True)
+        else:
+            if not Path(self.source).exists():
+                raise FileNotFoundError(
+                    errno.ENOENT, os.strerror(errno.ENOENT), str(self.source)
+                )
+            abs_out_path.mkdir(parents=True, exist_ok=True)
+            if not self.crate.source:
+                self.crate._copy_unlisted(self.source, abs_out_path)
+
     def write(self, base_path):
-        out_path = Path(base_path) / self.id
+        base_path = Path(base_path)
         if is_url(str(self.source)):
-            if self.validate_url and not self.fetch_remote:
+            self._write_from_url(base_path)
+        else:
+            self._copy_folder(base_path)
+
+    def stream(self, chunk_size=8192):
+        if self.source is None:
+            return
+        elif is_url(str(self.source)):
+            yield from self._stream_folder_from_url(chunk_size)
+        else:
+            yield from self._stream_folder_from_path(chunk_size)
+
+    def _stream_folder_from_path(self, chunk_size=8192):
+        if not Path(str(self.source)).exists():
+            raise FileNotFoundError(
+                errno.ENOENT, os.strerror(errno.ENOENT), str(self.source)
+            )
+        if not self.crate.source:
+            for root, _, files in os.walk(self.source):
+                root = Path(root)
+                for name in files:
+                    source = root / name
+                    dest = source.relative_to(Path(self.source).parent)
+                    with open(source, 'rb') as f:
+                        while chunk := f.read(chunk_size):
+                            yield str(dest), chunk
+
+    def _stream_folder_from_url(self, chunk_size=8192):
+        if not self.fetch_remote:
+            if self.validate_url:
                 with urlopen(self.source) as _:
                     self._jsonld['sdDatePublished'] = iso_now()
-            if self.fetch_remote:
-                self.__get_parts(out_path)
         else:
-            if self.source is None:
-                out_path.mkdir(parents=True, exist_ok=True)
-            else:
-                if not Path(self.source).exists():
-                    raise FileNotFoundError(
-                        errno.ENOENT, os.strerror(errno.ENOENT), str(self.source)
-                    )
-                out_path.mkdir(parents=True, exist_ok=True)
-                if not self.crate.source:
-                    self.crate._copy_unlisted(self.source, out_path)
+            base = self.source.rstrip("/")
+            for entry in self._jsonld.get("hasPart", []):
+                try:
+                    part = entry["@id"]
+                    if is_url(part) or part.startswith("/"):
+                        raise RuntimeError(f"'{self.source}': part '{part}' is not a relative path")
+                    part_uri = f"{base}/{part}"
+                    rel_out_path = Path(self.id) / part
 
-    def __get_parts(self, out_path):
-        out_path.mkdir(parents=True, exist_ok=True)
-        base = self.source.rstrip("/")
-        for entry in self._jsonld.get("hasPart", []):
-            try:
-                part = entry["@id"]
-            except KeyError:
-                continue
-            if is_url(part) or part.startswith("/"):
-                raise RuntimeError(f"'{self.source}': part '{part}' is not a relative path")
-            part_uri = f"{base}/{part}"
-            part_out_path = out_path / part
-            with urlopen(part_uri) as r, open(part_out_path, 'wb') as f:
-                shutil.copyfileobj(r, f)
+                    with urlopen(part_uri) as response:
+                        while chunk := response.read(chunk_size):
+                            yield str(rel_out_path), chunk
+                except KeyError:
+                    warnings.warn(f"'hasPart' entry in {self.id} is missing '@id'. Skipping.")
diff --git a/rocrate/model/entity.py b/rocrate/model/entity.py
index 0e504f06..d0cbcd62 100644
--- a/rocrate/model/entity.py
+++ b/rocrate/model/entity.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/file.py b/rocrate/model/file.py
index 8cd95286..d0363b76 100644
--- a/rocrate/model/file.py
+++ b/rocrate/model/file.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -40,41 +41,97 @@ def _empty(self):
         }
         return val
 
+    def _has_writeable_stream(self):
+        if isinstance(self.source, (BytesIO, StringIO)):
+            return True
+        elif is_url(str(self.source)):
+            return self.fetch_remote
+        else:
+            return self.source is not None
+
+    def _write_from_stream(self, out_file_path):
+        if not self._has_writeable_stream():
+            # is this does not correspond to a writeable stream (i.e. it is a url but fetch_remote is False),
+            # we still want to consume the stream to consume file headers, run the size calculation, etc.
+            all(self.stream())
+            return
+
+        out_file_path.parent.mkdir(parents=True, exist_ok=True)
+        with open(out_file_path, 'wb') as out_file:
+            for _, chunk in self.stream():
+                out_file.write(chunk)
+
+    def _copy_file(self, path, out_file_path):
+        out_file_path.parent.mkdir(parents=True, exist_ok=True)
+        if not out_file_path.exists() or not out_file_path.samefile(path):
+            shutil.copy(path, out_file_path)
+        if self.record_size:
+            self._jsonld['contentSize'] = str(out_file_path.stat().st_size)
+
     def write(self, base_path):
         out_file_path = Path(base_path) / self.id
-        if isinstance(self.source, (BytesIO, StringIO)):
-            out_file_path.parent.mkdir(parents=True, exist_ok=True)
-            mode = 'w' + ('b' if isinstance(self.source, BytesIO) else 't')
-            kw = {} if isinstance(self.source, BytesIO) else {'encoding': 'utf-8'}
-            with open(out_file_path, mode, **kw) as out_file:
-                content = self.source.getvalue()
-                out_file.write(content)
+        if isinstance(self.source, (BytesIO, StringIO)) or is_url(str(self.source)):
+            self._write_from_stream(out_file_path)
+        elif self.source is None:
+            # Allows to record a File entity whose @id does not exist, see #73
+            warnings.warn(f"No source for {self.id}")
+        else:
+            self._copy_file(self.source, out_file_path)
+
+    def _stream_from_stream(self, stream):
+        size = 0
+        read = stream.read()
+        if isinstance(self.source, StringIO):
+            read = read.encode('utf-8')
+        while len(read) > 0:
+            yield self.id, read
+            size += len(read)
+            read = stream.read()
+            if isinstance(self.source, StringIO):
+                read = read.encode('utf-8')
+
+        if self.record_size:
+            self._jsonld['contentSize'] = str(size)
+
+    def _stream_from_url(self, url, chunk_size=8192):
+        if self.fetch_remote or self.validate_url:
+            if self.validate_url:
+                if url.startswith("http"):
+                    with requests.head(url) as response:
+                        self._jsonld.update({
+                            'contentSize': response.headers.get('Content-Length'),
+                            'encodingFormat': response.headers.get('Content-Type')
+                        })
+                    if not self.fetch_remote:
+                        date_published = response.headers.get("Last-Modified", iso_now())
+                        self._jsonld['sdDatePublished'] = date_published
+            if self.fetch_remote:
+                size = 0
+                self._jsonld['contentUrl'] = str(url)
+                with urllib.request.urlopen(url) as response:
+                    while chunk := response.read(chunk_size):
+                        yield self.id, chunk
+                        size += len(chunk)
+
                 if self.record_size:
-                    self._jsonld['contentSize'] = str(len(content))
+                    self._jsonld['contentSize'] = str(size)
+
+    def _stream_from_file(self, path, chunk_size=8192):
+        size = 0
+        with open(path, 'rb') as f:
+            while chunk := f.read(chunk_size):
+                yield self.id, chunk
+                size += len(chunk)
+        if self.record_size:
+            self._jsonld['contentSize'] = str(size)
+
+    def stream(self, chunk_size=8192):
+        if isinstance(self.source, (BytesIO, StringIO)):
+            yield from self._stream_from_stream(self.source)
         elif is_url(str(self.source)):
-            if self.fetch_remote or self.validate_url:
-                if self.validate_url:
-                    if self.source.startswith("http"):
-                        with requests.head(self.source) as response:
-                            self._jsonld.update({
-                                'contentSize': response.headers.get('Content-Length'),
-                                'encodingFormat': response.headers.get('Content-Type')
-                            })
-                        if not self.fetch_remote:
-                            date_published = response.headers.get("Last-Modified", iso_now())
-                            self._jsonld['sdDatePublished'] = date_published
-                if self.fetch_remote:
-                    out_file_path.parent.mkdir(parents=True, exist_ok=True)
-                    urllib.request.urlretrieve(self.source, out_file_path)
-                    self._jsonld['contentUrl'] = str(self.source)
-                    if self.record_size:
-                        self._jsonld['contentSize'] = str(out_file_path.stat().st_size)
+            yield from self._stream_from_url(self.source, chunk_size)
         elif self.source is None:
             # Allows to record a File entity whose @id does not exist, see #73
             warnings.warn(f"No source for {self.id}")
         else:
-            out_file_path.parent.mkdir(parents=True, exist_ok=True)
-            if not out_file_path.exists() or not out_file_path.samefile(self.source):
-                shutil.copy(self.source, out_file_path)
-            if self.record_size:
-                self._jsonld['contentSize'] = str(out_file_path.stat().st_size)
+            yield from self._stream_from_file(self.source, chunk_size)
diff --git a/rocrate/model/file_or_dir.py b/rocrate/model/file_or_dir.py
index 4193b53e..a66e3c50 100644
--- a/rocrate/model/file_or_dir.py
+++ b/rocrate/model/file_or_dir.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/metadata.py b/rocrate/model/metadata.py
index aa7cf801..5d432a87 100644
--- a/rocrate/model/metadata.py
+++ b/rocrate/model/metadata.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -74,11 +75,16 @@ def generate(self):
             context = context[0]
         return {'@context': context, '@graph': graph}
 
-    def write(self, base_path):
-        write_path = Path(base_path) / self.id
-        as_jsonld = self.generate()
-        with open(write_path, 'w', encoding='utf-8') as outfile:
-            json.dump(as_jsonld, outfile, indent=4, sort_keys=True)
+    def stream(self, chunk_size=8192):
+        content = self.generate()
+        yield self.id, str.encode(json.dumps(content, indent=4, sort_keys=True), encoding='utf-8')
+
+    def _has_writeable_stream(self):
+        return True
+
+    def write(self, dest_base):
+        write_path = Path(dest_base) / self.id
+        super()._write_from_stream(write_path)
 
     @property
     def root(self) -> Dataset:
diff --git a/rocrate/model/person.py b/rocrate/model/person.py
index c6b6e6df..cfe7ec1f 100644
--- a/rocrate/model/person.py
+++ b/rocrate/model/person.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/preview.py b/rocrate/model/preview.py
index 12abf817..3f5e08b8 100644
--- a/rocrate/model/preview.py
+++ b/rocrate/model/preview.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -90,11 +91,15 @@ def is_object_list(a):
         out_html = src.render(crate=self.crate, context=context_entities, data=data_entities)
         return out_html
 
-    def write(self, dest_base):
+    def stream(self, chunk_size=8192):
         if self.source:
-            super().write(dest_base)
+            yield from super().stream()
         else:
-            write_path = Path(dest_base) / self.id
-            out_html = self.generate_html()
-            with open(write_path, 'w', encoding='utf-8') as outfile:
-                outfile.write(out_html)
+            yield self.id, str.encode(self.generate_html(), encoding='utf-8')
+
+    def _has_writeable_stream(self):
+        return True
+
+    def write(self, dest_base):
+        write_path = Path(dest_base) / self.id
+        super()._write_from_stream(write_path)
diff --git a/rocrate/model/root_dataset.py b/rocrate/model/root_dataset.py
index 2d52b2ee..ebef3814 100644
--- a/rocrate/model/root_dataset.py
+++ b/rocrate/model/root_dataset.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/softwareapplication.py b/rocrate/model/softwareapplication.py
index 874294b4..2cd3c530 100644
--- a/rocrate/model/softwareapplication.py
+++ b/rocrate/model/softwareapplication.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/testdefinition.py b/rocrate/model/testdefinition.py
index 3de24afd..a17677c1 100644
--- a/rocrate/model/testdefinition.py
+++ b/rocrate/model/testdefinition.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/testinstance.py b/rocrate/model/testinstance.py
index 94d9f0ef..956f4a33 100644
--- a/rocrate/model/testinstance.py
+++ b/rocrate/model/testinstance.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/testservice.py b/rocrate/model/testservice.py
index c5f44c12..c2b65988 100644
--- a/rocrate/model/testservice.py
+++ b/rocrate/model/testservice.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/model/testsuite.py b/rocrate/model/testsuite.py
index b99b103c..ba0442e0 100644
--- a/rocrate/model/testsuite.py
+++ b/rocrate/model/testsuite.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/rocrate.py b/rocrate/rocrate.py
index b489c948..6694c081 100644
--- a/rocrate/rocrate.py
+++ b/rocrate/rocrate.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -31,6 +32,7 @@
 from pathlib import Path
 from urllib.parse import urljoin
 
+from .memory_buffer import MemoryBuffer
 from .model import (
     ComputationalWorkflow,
     ComputerLanguage,
@@ -469,15 +471,56 @@ def write(self, base_path):
 
     def write_zip(self, out_path):
         out_path = Path(out_path)
-        if out_path.suffix == ".zip":
-            out_path = out_path.parent / out_path.stem
-        tmp_dir = tempfile.mkdtemp(prefix="rocrate_")
-        try:
-            self.write(tmp_dir)
-            archive = shutil.make_archive(out_path, "zip", tmp_dir)
-        finally:
-            shutil.rmtree(tmp_dir)
-        return archive
+        with open(out_path, "wb") as f:
+            for chunk in self._stream_zip(out_path=out_path):
+                f.write(chunk)
+        return out_path
+
+    def stream_zip(self, chunk_size=8192):
+        """ Create a stream of bytes representing the RO-Crate as a ZIP file. """
+        yield from self._stream_zip(chunk_size=chunk_size)
+
+    def _stream_zip(self, chunk_size=8192, out_path=None):
+        """ Create a stream of bytes representing the RO-Crate as a ZIP file.
+        The out_path argument is used to exclude the file from the ZIP stream if the output is inside the crate folder
+        and can be omitted if the stream is not written into a file inside the crate dir.
+        """
+        with MemoryBuffer() as buffer:
+            with zipfile.ZipFile(buffer, mode='w', compression=zipfile.ZIP_DEFLATED) as archive:
+                for writeable_entity in self.data_entities + self.default_entities:
+                    current_file_path, current_out_file = None, None
+                    for path, chunk in writeable_entity.stream(chunk_size=chunk_size):
+                        if path != current_file_path:
+                            if current_out_file:
+                                current_out_file.close()
+                            current_file_path = path
+                            current_out_file = archive.open(path, mode='w', force_zip64=True)
+                        current_out_file.write(chunk)
+                        while len(buffer) >= chunk_size:
+                            yield buffer.read(chunk_size)
+                    if current_out_file:
+                        current_out_file.close()
+
+                # add additional unlisted files to stream
+                listed_files = [archived_file for archived_file in archive.namelist()]
+                for root, dirs, files in walk(str(self.source), exclude=self.exclude):
+                    for name in files:
+                        source = Path(root) / name
+
+                        # ignore out_path to not include a zip in itself
+                        if out_path and out_path.samefile(source):
+                            continue
+
+                        rel = source.relative_to(self.source)
+                        if not self.dereference(str(rel)) and not str(rel) in listed_files:
+                            with archive.open(str(rel), mode='w') as out_file, open(source, 'rb') as in_file:
+                                while chunk := in_file.read(chunk_size):
+                                    out_file.write(chunk)
+                                    while len(buffer) >= chunk_size:
+                                        yield buffer.read(chunk_size)
+
+            while chunk := buffer.read(chunk_size):
+                yield chunk
 
     def add_workflow(
             self, source=None, dest_path=None, fetch_remote=False, validate_url=False, properties=None,
diff --git a/rocrate/utils.py b/rocrate/utils.py
index aa1aeab2..5f565187 100644
--- a/rocrate/utils.py
+++ b/rocrate/utils.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/rocrate/vocabs.py b/rocrate/vocabs.py
index e492294f..902a682d 100644
--- a/rocrate/vocabs.py
+++ b/rocrate/vocabs.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/setup.py b/setup.py
index c4fc1236..bc4a0765 100755
--- a/setup.py
+++ b/setup.py
@@ -7,6 +7,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -58,6 +59,7 @@
     long_description_content_type='text/markdown',
     long_description=long_description,
     author=", ".join((
+        'Daniel Bauer',
         'Eli Chadwick',
         'Paul De Geest',
         'Bert Droesbeke',
diff --git a/tools/add_boilerplate.py b/tools/add_boilerplate.py
index 22ad428f..73ba0e58 100644
--- a/tools/add_boilerplate.py
+++ b/tools/add_boilerplate.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.


Test patch:
diff --git a/examples/read_test_metadata.py b/examples/read_test_metadata.py
index 722d0a16..88b77d52 100644
--- a/examples/read_test_metadata.py
+++ b/examples/read_test_metadata.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/conftest.py b/test/conftest.py
index 3dfee400..b7488d51 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/test_cli.py b/test/test_cli.py
index b4fbb94c..353e9aea 100644
--- a/test/test_cli.py
+++ b/test/test_cli.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/test_jsonld.py b/test/test_jsonld.py
index 7c9759c9..44ee9492 100644
--- a/test/test_jsonld.py
+++ b/test/test_jsonld.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/test_metadata.py b/test/test_metadata.py
index e6ba0cea..ffacb5c1 100644
--- a/test/test_metadata.py
+++ b/test/test_metadata.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/test_model.py b/test/test_model.py
index 165084fd..08400871 100644
--- a/test/test_model.py
+++ b/test/test_model.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/test_read.py b/test/test_read.py
index c3b7a608..1b60b876 100644
--- a/test/test_read.py
+++ b/test/test_read.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/test_readwrite.py b/test/test_readwrite.py
index 0fab0d90..0c894049 100644
--- a/test/test_readwrite.py
+++ b/test/test_readwrite.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/test_test_metadata.py b/test/test_test_metadata.py
index 71c5e0ab..5645fe58 100644
--- a/test/test_test_metadata.py
+++ b/test/test_test_metadata.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/test_utils.py b/test/test_utils.py
index a73b4a1e..1476e9a5 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/test_workflow_ro_crate.py b/test/test_workflow_ro_crate.py
index eb4f5471..edad0018 100644
--- a/test/test_workflow_ro_crate.py
+++ b/test/test_workflow_ro_crate.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
diff --git a/test/test_write.py b/test/test_write.py
index 94835dab..8c09debb 100644
--- a/test/test_write.py
+++ b/test/test_write.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -395,6 +396,21 @@ def test_no_parts(tmpdir, helpers):
     assert "hasPart" not in json_entities["./"]
 
 
+def test_write_zip_copy_unlisted(test_data_dir, tmpdir):
+    crate_dir = test_data_dir / 'ro-crate-galaxy-sortchangecase'
+    crate = ROCrate(crate_dir)
+
+    zip_name = 'ro_crate_out.crate.zip'
+    zip_path = tmpdir / zip_name
+    crate.write_zip(zip_path)
+    out_path = tmpdir / 'ro_crate_out'
+    with zipfile.ZipFile(zip_path, "r") as zf:
+        zf.extractall(out_path)
+
+    assert (out_path / "test" / "test1" / "input.bed").is_file()
+    assert (out_path / "test" / "test1" / "output_exp.bed").is_file()
+
+
 def test_no_zip_in_zip(test_data_dir, tmpdir):
     crate_dir = test_data_dir / 'ro-crate-galaxy-sortchangecase'
     crate = ROCrate(crate_dir)
@@ -462,3 +478,25 @@ def test_http_header(tmpdir):
     assert "sdDatePublished" in props
     with requests.head(url) as response:
         assert props["sdDatePublished"] == response.headers.get("last-modified")
+
+
+def test_stream(test_data_dir, tmpdir):
+    source = test_data_dir / "read_crate"
+    crate = ROCrate(source)
+
+    out_path = tmpdir / 'ro_crate_out.zip'
+    with open(out_path, "wb") as out:
+        for chunk in crate.stream_zip():
+            out.write(chunk)
+
+    with zipfile.ZipFile(out_path, "r") as zf:
+        assert not zf.testzip()
+        for info in zf.infolist():
+            assert info.file_size > 0
+
+    extract_path = tmpdir / 'ro_crate_out'
+    with zipfile.ZipFile(out_path, "r") as zf:
+        zf.extractall(extract_path)
+    assert (extract_path / "ro-crate-metadata.jsonld").is_file()
+    assert (extract_path / "examples" / "README.txt").is_file()
+    assert (extract_path / "test" / "test-metadata.json").is_file()
diff --git a/test/test_wrroc.py b/test/test_wrroc.py
index 82405d07..66ab79aa 100644
--- a/test/test_wrroc.py
+++ b/test/test_wrroc.py
@@ -5,6 +5,7 @@
 # Copyright 2022-2024 École Polytechnique Fédérale de Lausanne, CH
 # Copyright 2024 Data Centre, SciLifeLab, SE
 # Copyright 2024 National Institute of Informatics (NII), JP
+# Copyright 2025 Senckenberg Society for Nature Research (SGN), DE
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.