diff --git a/src/stringx/client.py b/src/stringx/client.py
index 2c5b8a6..d0a1026 100644
--- a/src/stringx/client.py
+++ b/src/stringx/client.py
@@ -91,6 +91,18 @@ def interaction_partners(
 
         return self.request("interaction_partners", params=params)
 
+    def homology(
+        self, identifiers: list[str], species: int, *, format: str | None = None
+    ):
+        url = f"api/{format or self.format}/homology"
+
+        params = {
+            "identifiers": "\r".join(identifiers),
+            "species": species,
+        }
+
+        return self.post(url, params=params)
+
     def version(self) -> str:
         request = self.build_request("GET", "api/json/version")
         request.url = request.url.copy_remove_param("caller_identity")
diff --git a/tests/test_client.py b/tests/test_client.py
index 6f6dccd..5ae95ab 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -129,6 +129,23 @@ def test_interaction_partners(httpx_mock, test_client):
     test_client.interaction_partners(["id1", "id2"], 7227)
 
 
+@pytest.mark.parametrize("format", ["tsv", "tsv-no-header", "json", "xml"])
+def test_homology(httpx_mock, test_client, format):
+    identifiers = ["id1", "id2"]
+    species = 1234
+
+    httpx_mock.add_response()
+
+    test_client.homology(identifiers, species, format=format)
+
+    requested_url = httpx_mock.get_request().url
+
+    assert requested_url.path == f"/api/{format}/homology"
+    assert requested_url.params["identifiers"] == "\r".join(identifiers)
+    assert requested_url.params["species"] == str(species)
+    assert requested_url.params["caller_identity"] == test_client.identity
+
+
 def test_version(httpx_mock, test_client):
     httpx_mock.add_response(
         url=httpx.URL("https://string-db.org/api/json/version"),