diff --git a/esphome/espidf/component.py b/esphome/espidf/component.py
index 105413cf44..bed999656b 100644
--- a/esphome/espidf/component.py
+++ b/esphome/espidf/component.py
@@ -240,12 +240,17 @@ def generate_idf_component_yml(component: IDFComponent) -> str:
 
     data = {}
 
+    # Metadata only: tolerate malformed shapes instead of crashing on a
+    # third-party manifest (repository may legally be {"url": ...} or a
+    # plain URL string)
     description = component.data.get("description")
-    if description:
+    if isinstance(description, str) and description:
         data["description"] = description
 
-    repository = component.data.get("repository", {}).get("url", None)
-    if repository:
+    repository = component.data.get("repository")
+    if isinstance(repository, dict):
+        repository = repository.get("url")
+    if isinstance(repository, str) and repository:
         data["repository"] = repository
 
     for dependency in component.dependencies:
diff --git a/tests/unit_tests/test_espidf_component.py b/tests/unit_tests/test_espidf_component.py
index a7d871b2f8..3789eefc64 100644
--- a/tests/unit_tests/test_espidf_component.py
+++ b/tests/unit_tests/test_espidf_component.py
@@ -374,6 +374,18 @@ def test_generate_idf_component_yml_basic(tmp_component):
     assert result == "description: test\nrepository: http://aaa\n"
 
 
+def test_generate_idf_component_yml_tolerates_malformed_metadata(tmp_component):
+    """A string repository is the URL itself; junk shapes drop instead of
+    crashing on a third-party manifest."""
+    tmp_component.data = {"description": "test", "repository": "http://aaa"}
+    assert (
+        generate_idf_component_yml(tmp_component)
+        == "description: test\nrepository: http://aaa\n"
+    )
+    tmp_component.data = {"description": {"en": "x"}, "repository": 123}
+    assert generate_idf_component_yml(tmp_component) == "{}\n"
+
+
 def test_generate_idf_component_yml_with_dependencies(tmp_component, tmp_path):
     dep = IDFComponent("dep", "1.0", source=URLSource("http://dummy.com"))
     dep.path = tmp_path / "dep"