feat(prompts): allow prompt deletion

langfuse/_client/client.py

@@ -3775,6 +3775,35 @@ def update_prompt(
 
         return updated_prompt
 
+    def delete_prompt(
+        self,
+        name: str,
+        *,
+        label: Optional[str] = None,
+        version: Optional[int] = None,
+    ) -> None:
+        """Delete a prompt with all its versions or selected versions from Langfuse.
+
+        The Langfuse SDK prompt cache is invalidated for all cached versions with the specified name.
+
+        Args:
+            name: The name of the prompt to delete prompt versions for. If neither `label` nor `version` are specified, all prompt versions will be deleted.
+            label: Label of the prompt versions to delete. All prompt versions with the given label will be deleted.
+            version: Optional version of the prompt to delete.
+
+        Raises:
+            NotFoundError: If the prompt does not exist.
+            Error: If the API request fails.
+        """
+        self.api.prompts.delete(
+            prompt_name=self._url_encode(name),
+            label=label,
+            version=version,
+        )
+
+        if self._resources is not None:
+            self._resources.prompt_cache.invalidate(name)
+
     def _url_encode(self, url: str, *, is_url_param: Optional[bool] = False) -> str:
         # httpx ≥ 0.28 does its own WHATWG-compliant quoting (eg. encodes bare
         # “%”, “?”, “#”, “|”, … in query/path parts).  Re-quoting here would

tests/test_prompt.py

@@ -682,7 +682,7 @@ def test_prompt_end_to_end():
 @pytest.fixture
 def langfuse():
     from langfuse._client.resource_manager import LangfuseResourceManager
-    
+
     langfuse_instance = Langfuse()
     langfuse_instance.api = Mock()
 
@@ -1485,6 +1485,36 @@ def test_update_prompt():
     assert sorted(updated_prompt.labels) == expected_labels
 
 
+def test_delete_prompt():
+    """Test that deleting a prompt works and invalidates cache."""
+    langfuse = Langfuse()
+    prompt_name = f"folder/subfolder/{create_uuid()}"
+
+    langfuse.create_prompt(
+        name=prompt_name,
+        prompt="test prompt",
+        labels=["production"],
+    )
+
+    # Fetch to populate cache
+    cached_prompt = langfuse.get_prompt(prompt_name)
+    assert cached_prompt.prompt == "test prompt"
+
+    cache_key = PromptCache.generate_cache_key(
+        prompt_name, version=None, label="production"
+    )
+    assert langfuse._resources.prompt_cache.get(cache_key) is not None
+
+    langfuse.delete_prompt(prompt_name)
+
+    # Verify cache is invalidated
+    assert langfuse._resources.prompt_cache.get(cache_key) is None
+
+    # Verify prompt is deleted from server
+    with pytest.raises(NotFoundError):
+        langfuse.get_prompt(prompt_name, cache_ttl_seconds=0)
+
+
 def test_update_prompt_in_folder():
     langfuse = Langfuse()
     prompt_name = f"some-folder/{create_uuid()}"