From ffe3d0b2cdb2160af9352dbdfa6d0c8c45f8b368 Mon Sep 17 00:00:00 2001
From: ehhuang <ehhuang@users.noreply.github.com>
Date: Thu, 1 May 2025 13:17:36 -0700
Subject: [PATCH] fix: nullable param type for function call (#2086)

Nullable param type is not supported, e.g. ['string', 'null'], since it
fails type validation.

Tests:
Run inference with

        messages:
- content: You are a helpful assistant that can use tools to get
information.
          role: system
        - content: What's the temperature in San Francisco in celsius?
          role: user
        tools:
        - function:
            description: Get current temperature for a given location.
            name: get_weather
            parameters:
              additionalProperties: false
              properties:
                location:
description: "City and country e.g. Bogot\xE1, Colombia"
                  type: string
                unit:
                  description: "Unit of temperature, default to celsius"
                  type: [string, "null"]  # <= nullable type
              required:
              - location
              type: object
          type: function

Co-authored-by: Eric Huang <erichuang@fb.com>
---
 llama_stack/providers/utils/inference/openai_compat.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llama_stack/providers/utils/inference/openai_compat.py b/llama_stack/providers/utils/inference/openai_compat.py
index 1a8d82de2..d9dfba110 100644
--- a/llama_stack/providers/utils/inference/openai_compat.py
+++ b/llama_stack/providers/utils/inference/openai_compat.py
@@ -873,7 +873,7 @@ def _convert_openai_request_tools(tools: Optional[List[Dict[str, Any]]] = None)
             tool_param_properties = tool_params.get("properties", {})
             for tool_param_key, tool_param_value in tool_param_properties.items():
                 tool_param_def = ToolParamDefinition(
-                    param_type=tool_param_value.get("type", None),
+                    param_type=str(tool_param_value.get("type", None)),
                     description=tool_param_value.get("description", None),
                 )
                 lls_tool_params[tool_param_key] = tool_param_def