diff --git a/swh/loader/package/npm/loader.py b/swh/loader/package/npm/loader.py
--- a/swh/loader/package/npm/loader.py
+++ b/swh/loader/package/npm/loader.py
@@ -15,6 +15,8 @@
 
 from urllib.parse import quote
 from swh.model.model import (
+    MetadataAuthority,
+    MetadataAuthorityType,
     Person,
     RevisionType,
     Revision,
@@ -22,7 +24,11 @@
     Sha1Git,
 )
 
-from swh.loader.package.loader import BasePackageInfo, PackageLoader
+from swh.loader.package.loader import (
+    BasePackageInfo,
+    PackageLoader,
+    RawExtrinsicMetadataCore,
+)
 from swh.loader.package.utils import api_info, release_name
 
 
@@ -96,7 +102,8 @@
 
         """
         if not self._info:
-            self._info = json.loads(api_info(self.provider_url))
+            self._raw_info = api_info(self.provider_url)
+            self._info = json.loads(self._raw_info)
         return self._info
 
     def get_versions(self) -> Sequence[str]:
@@ -105,6 +112,22 @@
     def get_default_version(self) -> str:
         return self.info["dist-tags"].get("latest", "")
 
+    def get_metadata_authority(self):
+        return MetadataAuthority(
+            type=MetadataAuthorityType.FORGE,
+            url="https://replicate.npmjs.com/",
+            metadata={},
+        )
+
+    def get_extrinsic_snapshot_metadata(self):
+        return [
+            RawExtrinsicMetadataCore(
+                format="replicate-npm-package-json",
+                metadata=self._raw_info,
+                discovery_date=None,
+            ),
+        ]
+
     def get_package_info(self, version: str) -> Iterator[Tuple[str, NpmPackageInfo]]:
         p_info = NpmPackageInfo.from_metadata(
             project_metadata=self.info, version=version
diff --git a/swh/loader/package/npm/tests/test_npm.py b/swh/loader/package/npm/tests/test_npm.py
--- a/swh/loader/package/npm/tests/test_npm.py
+++ b/swh/loader/package/npm/tests/test_npm.py
@@ -7,9 +7,23 @@
 import os
 import pytest
 
-from swh.model.hashutil import hash_to_bytes
-from swh.model.model import Person, Snapshot, SnapshotBranch, TargetType
+from swh.model.hashutil import hash_to_bytes, hash_to_hex
+from swh.model.identifiers import SWHID
+from swh.model.model import (
+    MetadataAuthority,
+    MetadataAuthorityType,
+    MetadataFetcher,
+    MetadataTargetType,
+    Person,
+    RawExtrinsicMetadata,
+    Snapshot,
+    SnapshotBranch,
+    TargetType,
+)
+
+from swh.storage.interface import PagedResult
 
+from swh.loader.package import __version__
 from swh.loader.package.npm.loader import (
     _author_str,
     NpmLoader,
@@ -24,6 +38,12 @@
 )
 
 
+@pytest.fixture
+def org_api_info(datadir) -> bytes:
+    with open(os.path.join(datadir, "https_replicate.npmjs.com", "org"), "rb",) as f:
+        return f.read()
+
+
 def test_npm_author_str():
     for author, expected_author in [
         ("author", "author"),
@@ -322,7 +342,7 @@
         )
 
 
-def test_npm_loader_first_visit(swh_config, requests_mock_datadir):
+def test_npm_loader_first_visit(swh_config, requests_mock_datadir, org_api_info):
     package = "org"
     url = package_url(package)
     loader = NpmLoader(url)
@@ -387,6 +407,32 @@
     )
     check_snapshot(expected_snapshot, loader.storage)
 
+    snapshot_swhid = SWHID(
+        object_type="snapshot", object_id=hash_to_hex(expected_snapshot_id)
+    )
+    metadata_authority = MetadataAuthority(
+        type=MetadataAuthorityType.FORGE, url="https://replicate.npmjs.com/",
+    )
+    expected_metadata = [
+        RawExtrinsicMetadata(
+            type=MetadataTargetType.SNAPSHOT,
+            id=snapshot_swhid,
+            authority=metadata_authority,
+            fetcher=MetadataFetcher(
+                name="swh.loader.package.npm.loader.NpmLoader", version=__version__,
+            ),
+            discovery_date=loader.visit_date,
+            format="replicate-npm-package-json",
+            metadata=org_api_info,
+            origin="https://www.npmjs.com/package/org",
+        )
+    ]
+    assert loader.storage.raw_extrinsic_metadata_get(
+        type=MetadataTargetType.SNAPSHOT,
+        id=snapshot_swhid,
+        authority=metadata_authority,
+    ) == PagedResult(next_page_token=None, results=expected_metadata,)
+
 
 def test_npm_loader_incremental_visit(swh_config, requests_mock_datadir_visits):
     package = "org"