diff --git a/src/fetchcode/composer.py b/src/fetchcode/composer.py
new file mode 100644
index 0000000..32b73f0
--- /dev/null
+++ b/src/fetchcode/composer.py
@@ -0,0 +1,57 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/aboutcode-org/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at:
+# http://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 packageurl import PackageURL
+
+from fetchcode import fetch_json_response
+
+
+class Composer:
+
+    purl_pattern = "pkg:composer/.*"
+    base_url = "https://repo.packagist.org"
+
+    @classmethod
+    def get_download_url(cls, purl):
+
+        """
+        Return the download URL for a Composer PURL.
+        """
+        purl = PackageURL.from_string(purl)
+
+        if not purl.name or not purl.version:
+            raise ValueError("Composer PURL must specify a name and version")
+
+        name = f"{purl.namespace}/{purl.name}" if purl.namespace else purl.name
+
+        url = f"{cls.base_url}/p2/{name}.json"
+        data = fetch_json_response(url)
+
+        if "packages" not in data:
+            return
+
+        if name not in data["packages"]:
+            return
+
+        for package in data["packages"][name]:
+            if (
+                package.get("version") == purl.version
+                or package.get("version") == f"v{purl.version}"
+                or package.get("version_normalized") == purl.version
+                or package.get("version_normalized") == f"v{purl.version}"
+            ):
+                download_url = package["dist"].get("url")
+                return download_url
diff --git a/src/fetchcode/cpan.py b/src/fetchcode/cpan.py
new file mode 100644
index 0000000..8e446ec
--- /dev/null
+++ b/src/fetchcode/cpan.py
@@ -0,0 +1,58 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/aboutcode-org/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at:
+# http://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.
+
+import urllib.parse
+
+from packageurl import PackageURL
+
+from fetchcode import fetch_json_response
+from fetchcode.utils import _http_exists
+
+
+class CPAN:
+    purl_pattern = "pkg:cpan/.*"
+    base_url = "https://cpan.metacpan.org/"
+
+    def get_download_url(purl: str):
+        """
+        Resolve a CPAN PURL to a verified, downloadable archive URL.
+        Strategy: MetaCPAN API -> verified URL; fallback to author-based path if available.
+        """
+        p = PackageURL.from_string(purl)
+        if not p.name or not p.version:
+            return None
+
+        parsed_name = urllib.parse.quote(p.name)
+        parsed_version = urllib.parse.quote(p.version)
+        api = f"https://fastapi.metacpan.org/v1/release/{parsed_name}/{parsed_version}"
+        if _http_exists(api):
+            # Fetch release data from MetaCPAN API
+            # Example: https://fastapi.metacpan.org/v1/release/Some-Module/1.2.3
+            data = fetch_json_response(url=api)
+            url = data.get("download_url") or data.get("archive")
+            if url and _http_exists(url):
+                return url
+
+        author = p.namespace
+        if not author:
+            return
+        auth = author.upper()
+        a = auth[0]
+        ab = auth[:2] if len(auth) >= 2 else auth
+        for ext in (".tar.gz", ".zip"):
+            url = f"https://cpan.metacpan.org/authors/id/{a}/{ab}/{auth}/{p.name}-{p.version}{ext}"
+            if _http_exists(url):
+                return url
diff --git a/src/fetchcode/cran.py b/src/fetchcode/cran.py
new file mode 100644
index 0000000..52a49ed
--- /dev/null
+++ b/src/fetchcode/cran.py
@@ -0,0 +1,46 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/aboutcode-org/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at:
+# http://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 packageurl import PackageURL
+
+from fetchcode.utils import _http_exists
+
+
+class CRAN:
+    """
+    This class handles CRAN PURLs.
+    """
+
+    purl_pattern = "pkg:cran/.*"
+    base_url = "https://cran.r-project.org"
+
+    @classmethod
+    def get_download_url(cls, purl: str):
+        """
+        Resolve a CRAN PURL to a verified, downloadable source tarball URL.
+        Tries current contrib first, then Archive.
+        """
+        p = PackageURL.from_string(purl)
+        if not p.name or not p.version:
+            return None
+
+        current_url = f"{cls.base_url}/src/contrib/{p.name}_{p.version}.tar.gz"
+        if _http_exists(current_url):
+            return current_url
+
+        archive_url = f"{cls.base_url}/src/contrib/Archive/{p.name}/{p.name}_{p.version}.tar.gz"
+        if _http_exists(archive_url):
+            return archive_url
diff --git a/src/fetchcode/download_urls.py b/src/fetchcode/download_urls.py
index 8594006..c0e89b3 100644
--- a/src/fetchcode/download_urls.py
+++ b/src/fetchcode/download_urls.py
@@ -17,11 +17,13 @@
 from packageurl.contrib.route import NoRouteAvailable
 from packageurl.contrib.route import Router
 
+from fetchcode.composer import Composer
+from fetchcode.cpan import CPAN
+from fetchcode.cran import CRAN
+from fetchcode.huggingface import Huggingface
 from fetchcode.pypi import Pypi
 
-package_registry = [
-    Pypi,
-]
+package_registry = [Pypi, CRAN, CPAN, Huggingface, Composer]
 
 router = Router()
 
diff --git a/src/fetchcode/huggingface.py b/src/fetchcode/huggingface.py
new file mode 100644
index 0000000..c3b63c1
--- /dev/null
+++ b/src/fetchcode/huggingface.py
@@ -0,0 +1,53 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/aboutcode-org/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at:
+# http://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 packageurl import PackageURL
+
+from fetchcode import fetch_json_response
+
+
+class Huggingface:
+    """
+    This class handles huggingface PURLs.
+    """
+
+    purl_pattern = "pkg:huggingface/.*"
+
+    @classmethod
+    def get_download_url(cls, purl: str):
+        """
+        Return the download URL for a Hugging Face PURL.
+        """
+        p = PackageURL.from_string(purl)
+        if not p.name:
+            return None
+
+        revision = p.version or "main"
+        model_id = f"{p.namespace}/{p.name}" if p.namespace else p.name
+        q = p.qualifiers or {}
+
+        api_url = f"https://huggingface.co/api/models/{model_id}?revision={revision}"
+        data = fetch_json_response(api_url)
+        siblings = data.get("siblings", [])
+
+        ALLOWED_EXECUTABLE_EXTS = (".bin",)
+
+        for sib in siblings:
+            file_name = sib.get("rfilename")
+            if not file_name.endswith(ALLOWED_EXECUTABLE_EXTS):
+                continue
+            url = f"https://huggingface.co/{model_id}/resolve/{revision}/{file_name}"
+            return url
diff --git a/src/fetchcode/pypi.py b/src/fetchcode/pypi.py
index 96b6916..b8c4038 100644
--- a/src/fetchcode/pypi.py
+++ b/src/fetchcode/pypi.py
@@ -23,7 +23,7 @@
 
 class Pypi:
     """
-    This class handles Cargo PURLs.
+    This class handles Pypi PURLs.
     """
 
     purl_pattern = "pkg:pypi/.*"
diff --git a/src/fetchcode/utils.py b/src/fetchcode/utils.py
index 81ac9df..43345d9 100644
--- a/src/fetchcode/utils.py
+++ b/src/fetchcode/utils.py
@@ -243,3 +243,14 @@ def get_first_three_md5_hash_characters(podname):
     create a hash (using md5) of it and take the first three characters."
     """
     return md5_hasher(podname.encode("utf-8")).hexdigest()[0:3]
+
+
+def _http_exists(url: str) -> bool:
+    """
+    Lightweight existence check using a ranged GET so CDNs/servers that ignore HEAD still work.
+    """
+    try:
+        resp = make_head_request(url, headers={"Range": "bytes=0-0"})
+        return resp is not None and resp.status_code in (200, 206)
+    except Exception:
+        return False
diff --git a/tests/test_composer.py b/tests/test_composer.py
new file mode 100644
index 0000000..443c681
--- /dev/null
+++ b/tests/test_composer.py
@@ -0,0 +1,81 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/aboutcode-org/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at:
+# http://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 unittest.mock import patch
+
+import pytest
+
+from fetchcode.composer import Composer
+
+
+def test_valid_composer_package_with_namespace():
+    purl = "pkg:composer/laravel/framework@10.0.0"
+    name = "laravel/framework"
+    expected_url = f"https://repo.packagist.org/p2/{name}.json"
+    download_url = "https://github.com/laravel/framework/archive/refs/tags/v10.0.0.zip"
+
+    mock_data = {"packages": {name: [{"version": "10.0.0", "dist": {"url": download_url}}]}}
+
+    with patch("fetchcode.composer.fetch_json_response", return_value=mock_data) as mock_fetch:
+        result = Composer.get_download_url(purl)
+        assert result == download_url
+        mock_fetch.assert_called_once_with(expected_url)
+
+
+def test_valid_composer_package_without_namespace():
+    purl = "pkg:composer/some-package@1.0.0"
+    name = "some-package"
+    expected_url = f"https://repo.packagist.org/p2/{name}.json"
+    download_url = "https://example.org/some-package-1.0.0.zip"
+
+    mock_data = {"packages": {name: [{"version": "1.0.0", "dist": {"url": download_url}}]}}
+
+    with patch("fetchcode.composer.fetch_json_response", return_value=mock_data) as mock_fetch:
+        result = Composer.get_download_url(purl)
+        assert result == download_url
+        mock_fetch.assert_called_once_with(expected_url)
+
+
+def test_version_not_found_returns_none():
+    purl = "pkg:composer/laravel/framework@10.0.0"
+    name = "laravel/framework"
+    mock_data = {"packages": {name: [{"version": "9.0.0", "dist": {"url": "https://old.zip"}}]}}
+
+    with patch("fetchcode.composer.fetch_json_response", return_value=mock_data):
+        result = Composer.get_download_url(purl)
+        assert result is None
+
+
+def test_missing_packages_key_returns_none():
+    purl = "pkg:composer/laravel/framework@10.0.0"
+    with patch("fetchcode.composer.fetch_json_response", return_value={}):
+        result = Composer.get_download_url(purl)
+        assert result is None
+
+
+def test_missing_package_name_in_data_returns_none():
+    purl = "pkg:composer/laravel/framework@10.0.0"
+    mock_data = {"packages": {"some/other": []}}
+
+    with patch("fetchcode.composer.fetch_json_response", return_value=mock_data):
+        result = Composer.get_download_url(purl)
+        assert result is None
+
+
+def test_missing_version_raises():
+    purl = "pkg:composer/laravel/framework"
+    with pytest.raises(ValueError, match="Composer PURL must specify a name and version"):
+        Composer.get_download_url(purl)
diff --git a/tests/test_cpan.py b/tests/test_cpan.py
new file mode 100644
index 0000000..374af41
--- /dev/null
+++ b/tests/test_cpan.py
@@ -0,0 +1,86 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/aboutcode-org/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at:
+# http://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 unittest.mock import patch
+
+import pytest
+
+from fetchcode.cpan import CPAN
+
+get_download_url = CPAN.get_download_url
+
+
+@pytest.fixture
+def valid_purl():
+    return "pkg:cpan/EXAMPLE/Some-Module@1.2.3"
+
+
+def test_success_from_metacpan_api(valid_purl):
+    expected_url = "https://cpan.metacpan.org/authors/id/E/EX/EXAMPLE/Some-Module-1.2.3.tar.gz"
+
+    with patch("fetchcode.cpan.fetch_json_response") as mock_fetch, patch(
+        "fetchcode.cpan._http_exists"
+    ) as mock_exists:
+        mock_fetch.return_value = {"download_url": expected_url}
+        mock_exists.return_value = True
+        result = get_download_url(valid_purl)
+        assert result == expected_url
+        mock_fetch.assert_called_once()
+        assert mock_exists.call_count == 2
+
+
+def test_fallback_to_author_path(valid_purl):
+    expected_url = "https://cpan.metacpan.org/authors/id/E/EX/EXAMPLE/Some-Module-1.2.3.tar.gz"
+
+    with patch("fetchcode.cpan.fetch_json_response", side_effect=Exception("API error")), patch(
+        "fetchcode.cpan._http_exists"
+    ) as mock_exists:
+
+        mock_exists.side_effect = lambda url: url.endswith(".tar.gz")
+
+        result = get_download_url(valid_purl)
+        assert result == expected_url
+        assert mock_exists.call_count >= 1
+
+
+def test_author_zip_fallback(valid_purl):
+    tar_url = "https://cpan.metacpan.org/authors/id/E/EX/EXAMPLE/Some-Module-1.2.3.tar.gz"
+    zip_url = "https://cpan.metacpan.org/authors/id/E/EX/EXAMPLE/Some-Module-1.2.3.zip"
+
+    with patch("fetchcode.cpan.fetch_json_response", return_value={}), patch(
+        "fetchcode.cpan._http_exists"
+    ) as mock_exists:
+
+        mock_exists.side_effect = lambda url: url == zip_url
+
+        result = get_download_url(valid_purl)
+        assert result == zip_url
+        assert mock_exists.call_count == 3
+        assert tar_url in [call[0][0] for call in mock_exists.call_args_list]
+
+
+def test_neither_api_nor_fallback_works(valid_purl):
+    with patch("fetchcode.cpan.fetch_json_response", return_value={}), patch(
+        "fetchcode.cpan._http_exists", return_value=False
+    ) as mock_exists:
+
+        result = get_download_url(valid_purl)
+        assert result is None
+        assert mock_exists.call_count == 3
+
+
+def test_missing_name_or_version():
+    assert get_download_url("pkg:cpan/EXAMPLE/Some-Module") is None
diff --git a/tests/test_cran.py b/tests/test_cran.py
new file mode 100644
index 0000000..021df51
--- /dev/null
+++ b/tests/test_cran.py
@@ -0,0 +1,86 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/aboutcode-org/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at:
+# http://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 unittest.mock import patch
+
+import pytest
+
+from fetchcode.cran import CRAN
+
+get_download_url = CRAN.get_download_url
+
+
+@pytest.fixture
+def valid_purl():
+    return "pkg:cran/dplyr@1.0.0"
+
+
+def test_current_url_exists(valid_purl):
+    current_url = "https://cran.r-project.org/src/contrib/dplyr_1.0.0.tar.gz"
+
+    with patch("fetchcode.cran._http_exists", return_value=True) as mock_check:
+        result = get_download_url(valid_purl)
+        assert result == current_url
+        mock_check.assert_called_once_with(current_url)
+
+
+def test_fallback_to_archive(valid_purl):
+    current_url = "https://cran.r-project.org/src/contrib/dplyr_1.0.0.tar.gz"
+    archive_url = "https://cran.r-project.org/src/contrib/Archive/dplyr/dplyr_1.0.0.tar.gz"
+
+    def side_effect(url):
+        return url == archive_url
+
+    with patch("fetchcode.cran._http_exists", side_effect=side_effect) as mock_check:
+        result = get_download_url(valid_purl)
+        assert result == archive_url
+        assert mock_check.call_count == 2
+        mock_check.assert_any_call(current_url)
+        mock_check.assert_any_call(archive_url)
+
+
+def test_neither_url_exists(valid_purl):
+    with patch("fetchcode.cran._http_exists", return_value=False) as mock_check:
+        result = get_download_url(valid_purl)
+        assert result is None
+        assert mock_check.call_count == 2
+
+
+def test_missing_version_returns_none():
+    result = get_download_url("pkg:cran/dplyr")
+    assert result is None
+
+
+def test_version_with_dash():
+    purl = "pkg:cran/somepkg@1.2-3"
+
+    with patch("fetchcode.cran._http_exists", return_value=True) as mock_check:
+        result = get_download_url(purl)
+        assert result == "https://cran.r-project.org/src/contrib/somepkg_1.2-3.tar.gz"
+        mock_check.assert_called_once_with(
+            "https://cran.r-project.org/src/contrib/somepkg_1.2-3.tar.gz"
+        )
+
+
+def test_name_with_dot():
+    purl = "pkg:cran/foo.bar@2.0.1"
+
+    with patch("fetchcode.cran._http_exists", return_value=True) as mock_check:
+        result = get_download_url(purl)
+        assert result == "https://cran.r-project.org/src/contrib/foo.bar_2.0.1.tar.gz"
+        mock_check.assert_called_once_with(
+            "https://cran.r-project.org/src/contrib/foo.bar_2.0.1.tar.gz"
+        )
diff --git a/tests/test_download_urls.py b/tests/test_download_urls.py
new file mode 100644
index 0000000..464de85
--- /dev/null
+++ b/tests/test_download_urls.py
@@ -0,0 +1,46 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/aboutcode-org/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at:
+# http://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 unittest.mock import patch
+
+import pytest
+from packageurl.contrib.route import NoRouteAvailable
+
+from fetchcode.download_urls import download_url
+from fetchcode.download_urls import router
+
+
+def test_right_class_being_called_for_the_purls():
+    purls = [
+        "pkg:pypi/requests@2.31.0",
+        "pkg:cpan/EXAMPLE/Some-Module@1.2.3",
+        "pkg:composer/laravel/framework@10.0.0",
+        "pkg:cran/dplyr@1.0.0",
+    ]
+
+    with patch("fetchcode.download_urls.Router.process") as mock_fetch:
+        for purl in purls:
+            assert download_url(purl) is not None, f"Failed for purl: {purl}"
+
+
+def test_with_invalid_purls():
+    invalid_purls = [
+        "pkg:invalid/requests",
+        "pkg:xyz/dplyr",
+    ]
+    for purl in invalid_purls:
+        with pytest.raises(NoRouteAvailable):
+            router.process(purl)
diff --git a/tests/test_huggingface.py b/tests/test_huggingface.py
new file mode 100644
index 0000000..45fbf6c
--- /dev/null
+++ b/tests/test_huggingface.py
@@ -0,0 +1,65 @@
+# fetchcode is a free software tool from nexB Inc. and others.
+# Visit https://github.com/aboutcode-org/fetchcode for support and download.
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# http://nexb.com and http://aboutcode.org
+#
+# This software is licensed under the Apache License version 2.0.
+#
+# You may not use this software except in compliance with the License.
+# You may obtain a copy of the License at:
+# http://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 unittest.mock import patch
+
+from fetchcode.huggingface import Huggingface
+
+
+def test_returns_bin_file_url():
+    purl = "pkg:huggingface/facebook/opt-350m"
+    revision = "main"
+    expected_url = "https://huggingface.co/facebook/opt-350m/resolve/main/pytorch_model.bin"
+
+    mock_data = {
+        "siblings": [
+            {"rfilename": "config.json"},
+            {"rfilename": "pytorch_model.bin"},
+        ]
+    }
+
+    with patch("fetchcode.huggingface.fetch_json_response", return_value=mock_data):
+        result = Huggingface.get_download_url(purl)
+        assert result == expected_url
+
+
+def test_no_executable_files_returns_none():
+    purl = "pkg:huggingface/facebook/opt-350m"
+    mock_data = {
+        "siblings": [
+            {"rfilename": "config.json"},
+            {"rfilename": "tokenizer.json"},
+        ]
+    }
+
+    with patch("fetchcode.huggingface.fetch_json_response", return_value=mock_data):
+        result = Huggingface.get_download_url(purl)
+        assert result is None
+
+
+def test_custom_revision_in_purl():
+    purl = "pkg:huggingface/facebook/opt-350m@v1.0"
+    expected_url = "https://huggingface.co/facebook/opt-350m/resolve/v1.0/pytorch_model.bin"
+
+    mock_data = {
+        "siblings": [
+            {"rfilename": "pytorch_model.bin"},
+        ]
+    }
+
+    with patch("fetchcode.huggingface.fetch_json_response", return_value=mock_data):
+        result = Huggingface.get_download_url(purl)
+        assert result == expected_url