From 4115a165aa5b95b78cceb5b393d17200e1115bf9 Mon Sep 17 00:00:00 2001
From: rechain <ryan@aminochain.io>
Date: Wed, 25 Feb 2026 23:03:49 -0500
Subject: [PATCH] asyncapi link bug

---
 fastapi/applications.py |  2 +-
 tests/test_asyncapi.py  | 25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/fastapi/applications.py b/fastapi/applications.py
index 84a951c843..2b6ff05bf2 100644
--- a/fastapi/applications.py
+++ b/fastapi/applications.py
@@ -1222,7 +1222,7 @@ class FastAPI(Starlette):
                 if oauth2_redirect_url:
                     oauth2_redirect_url = root_path + oauth2_redirect_url
                 asyncapi_docs_url = None
-                if self.asyncapi_docs_url:
+                if self.asyncapi_url and self.asyncapi_docs_url:
                     asyncapi_docs_url = root_path + self.asyncapi_docs_url
                 return get_swagger_ui_html(
                     openapi_url=openapi_url,
diff --git a/tests/test_asyncapi.py b/tests/test_asyncapi.py
index 5ce436348c..5dff11cb0c 100644
--- a/tests/test_asyncapi.py
+++ b/tests/test_asyncapi.py
@@ -402,3 +402,28 @@ def test_get_asyncapi_direct():
     assert schema["asyncapi"] == "2.6.0"
     assert schema["info"]["title"] == "Test API"
     assert "/ws" in schema["channels"]
+
+
+def test_asyncapi_url_none_no_link_in_swagger():
+    """Test that Swagger UI doesn't show AsyncAPI link when asyncapi_url is None."""
+    app = FastAPI(
+        title="Test API",
+        version="1.0.0",
+        asyncapi_url=None,  # Explicitly disabled
+        # asyncapi_docs_url defaults to "/asyncapi-docs"
+    )
+
+    @app.websocket("/ws")
+    async def websocket_endpoint(websocket: WebSocket):
+        await websocket.accept()
+        await websocket.close()
+
+    client = TestClient(app)
+    # Swagger UI should not show AsyncAPI link when asyncapi_url is None
+    response = client.get("/docs")
+    assert response.status_code == 200, response.text
+    assert "/asyncapi-docs" not in response.text
+
+    # AsyncAPI endpoint should not exist
+    response = client.get("/asyncapi-docs")
+    assert response.status_code == 404