fix: Add max_completion_tokens to openai param validation (#6550)

* fix: Add max_completion_tokens to openai param validation
* feat(client): Handle max_completion_tokens in openai sdk

js/.changeset/brown-months-shout.md

@@ -0,0 +1,5 @@
+---
+"@arizeai/phoenix-client": patch
+---
+
+Update type definitions to include max_completion_tokens openai parameter

packages/phoenix-client/src/phoenix/client/helpers/sdk/openai/chat.py

@@ -69,6 +69,7 @@ class _ToolKwargs(TypedDict, total=False):
 class _InvocationParameters(TypedDict, total=False):
     frequency_penalty: float
     max_completion_tokens: int
+    max_tokens: int
     presence_penalty: float
     reasoning_effort: ChatCompletionReasoningEffort
     seed: int
@@ -197,8 +198,10 @@ def to_openai(
         if obj["type"] == "openai":
             openai_params: v1.PromptOpenAIInvocationParametersContent
             openai_params = obj["openai"]
+            if "max_completion_tokens" in openai_params:
+                ans["max_completion_tokens"] = openai_params["max_completion_tokens"]
             if "max_tokens" in openai_params:
-                ans["max_completion_tokens"] = openai_params["max_tokens"]
+                ans["max_tokens"] = openai_params["max_tokens"]
             if "temperature" in openai_params:
                 ans["temperature"] = openai_params["temperature"]
             if "top_p" in openai_params:
@@ -214,8 +217,10 @@ def to_openai(
         elif obj["type"] == "azure_openai":
             azure_params: v1.PromptAzureOpenAIInvocationParametersContent
             azure_params = obj["azure_openai"]
+            if "max_completion_tokens" in azure_params:
+                ans["max_completion_tokens"] = azure_params["max_completion_tokens"]
             if "max_tokens" in azure_params:
-                ans["max_completion_tokens"] = azure_params["max_tokens"]
+                ans["max_tokens"] = azure_params["max_tokens"]
             if "temperature" in azure_params:
                 ans["temperature"] = azure_params["temperature"]
             if "top_p" in azure_params:
@@ -299,7 +304,9 @@ def from_openai(
         else:
             assert_never(model_provider)
         if "max_completion_tokens" in obj and obj["max_completion_tokens"] is not None:
-            content["max_tokens"] = obj["max_completion_tokens"]
+            content["max_completion_tokens"] = obj["max_completion_tokens"]
+        if "max_tokens" in obj and obj["max_tokens"] is not None:
+            content["max_tokens"] = obj["max_tokens"]
         if "temperature" in obj and obj["temperature"] is not None:
             content["temperature"] = obj["temperature"]
         if "top_p" in obj and obj["top_p"] is not None:

packages/phoenix-client/tests/canary/sdk/openai/test_chat.py

@@ -424,6 +424,42 @@ class TestCompletionCreateParamsBase:
                 "max_completion_tokens": randint(1, 256),
                 "top_p": random(),
             },
+            {
+                "model": token_hex(8),
+                "messages": [
+                    {
+                        "role": "system",
+                        "content": "You are a UI generator. Convert the user input into a UI.",
+                    },
+                    {
+                        "role": "user",
+                        "content": "Make a form for {{ feature }}.",
+                    },
+                ],
+                "response_format": cast(
+                    "ResponseFormat",
+                    type_to_response_format_param(
+                        create_model("Response", ui=(_UI, ...)),
+                    ),
+                ),
+                "temperature": random(),
+                "max_tokens": randint(1, 256),
+                "top_p": random(),
+            },
+            {
+                "model": token_hex(8),
+                "messages": [
+                    {
+                        "role": "user",
+                        "content": "What is the latest population estimate for {{ location }}?",
+                    }
+                ],
+                "tools": _TOOLS,
+                "tool_choice": "required",
+                "temperature": random(),
+                "max_tokens": randint(1, 256),
+                "top_p": random(),
+            },
         ],
     )
     def test_round_trip(self, obj: CompletionCreateParamsBase) -> None:

schemas/openapi.json

@@ -2309,6 +2309,10 @@
             "type": "integer",
             "title": "Max Tokens"
           },
+          "max_completion_tokens": {
+            "type": "integer",
+            "title": "Max Completion Tokens"
+          },
           "frequency_penalty": {
             "type": "number",
             "title": "Frequency Penalty"
@@ -2539,6 +2543,10 @@
             "type": "integer",
             "title": "Max Tokens"
           },
+          "max_completion_tokens": {
+            "type": "integer",
+            "title": "Max Completion Tokens"
+          },
           "frequency_penalty": {
             "type": "number",
             "title": "Frequency Penalty"

src/phoenix/server/api/helpers/prompts/models.py

@@ -348,6 +348,7 @@ class AnthropicToolDefinition(PromptModel):
 class PromptOpenAIInvocationParametersContent(PromptModel):
     temperature: float = UNDEFINED
     max_tokens: int = UNDEFINED
+    max_completion_tokens: int = UNDEFINED
     frequency_penalty: float = UNDEFINED
     presence_penalty: float = UNDEFINED
     top_p: float = UNDEFINED

tests/integration/prompts/test_prompts.py

@@ -386,6 +386,7 @@ class TestClient:
                     top_p=random(),
                     presence_penalty=random(),
                     frequency_penalty=random(),
+                    max_tokens=randint(1, 256),
                     seed=randint(24, 42),
                     messages=[
                         {"role": "system", "content": "You are {role}."},
@@ -403,6 +404,7 @@ class TestClient:
                     top_p=random(),
                     presence_penalty=random(),
                     frequency_penalty=random(),
+                    max_completion_tokens=randint(1, 256),
                     seed=randint(24, 42),
                     messages=[
                         {