Add tools calling for dspy.LM

dspy/clients/lm.py

@@ -86,7 +86,13 @@ def __init__(
             ), "OpenAI's o1-* models require passing temperature=1.0 and max_tokens >= 5000 to `dspy.LM(...)`"
 
     @with_callbacks
-    def __call__(self, prompt=None, messages=None, **kwargs):
+    def __call__(self, prompt=None, messages=None, tools=None, **kwargs):
+        if tools is not None and not litellm.supports_function_calling(self.model):
+            raise ValueError(
+                f"The model {self.model} does not support function calling, but tools were provided. Please use a "
+                "model that supports function calling."
+            )
+
         # Build the request.
         cache = kwargs.pop("cache", self.cache)
         messages = messages or [{"role": "user", "content": prompt}]
@@ -99,7 +105,7 @@ def __call__(self, prompt=None, messages=None, **kwargs):
             completion = cached_litellm_text_completion if cache else litellm_text_completion
 
         response = completion(
-            request=dict(model=self.model, messages=messages, **kwargs),
+            request=dict(model=self.model, messages=messages, tools=tools, **kwargs),
             num_retries=self.num_retries,
         )
         if kwargs.get("logprobs"):
@@ -110,6 +116,8 @@ def __call__(self, prompt=None, messages=None, **kwargs):
                 }
                 for c in response["choices"]
             ]
+        elif tools:
+            outputs = [{"text": c.message.content, "tool_calls": c.message.tool_calls} for c in response["choices"]]
         else:
             outputs = [c.message.content if hasattr(c, "message") else c["text"] for c in response["choices"]]
 

tests/clients/test_lm.py

@@ -156,3 +156,35 @@ def test_lm_text_calls_are_retried_for_expected_failures(
 
     request_logs = read_litellm_test_server_request_logs(server_log_file_path)
     assert len(request_logs) == expected_num_retries + 1  # 1 initial request + 1 retries
+
+
+def test_tools_rejected_for_non_function_models():
+    with pytest.raises(ValueError):
+        lm = dspy.LM(model="palm/chat-bison")
+        lm("query", tools=[{"type": "function", "function": {}}])
+
+
+def test_lm_tool_calls_are_returned(litellm_test_server):
+    api_base, server_log_file_path = litellm_test_server
+
+    openai_lm = dspy.LM(
+        model="openai/dspy-test-model",
+        api_base=api_base,
+        api_key="fakekey",
+        model_type="chat",
+        cache=False,
+    )
+    tools = [
+        {
+            "type": "function",
+            "function": {
+                "name": "get_weather",
+                "parameters": {
+                    "type": "object",
+                    "properties": {"location": {"type": "string"}},
+                },
+            },
+        }
+    ]
+    outputs = openai_lm("Query", tools=tools)
+    assert "tool_calls" in outputs[0]