Nested properties in tool/function parameters not supported in Responses API

API Bugs
1

Responses API responds with an error like There was an issue with your request. Please check your inputs and try again if there is an included tool/function schema property that itself has properties. I.e. nested properties. This is not a problem in Completions API.

The following tool schema is fine in Completions API, but results in an error in Responses API:

{
  "function": {
    "description": "some tool.",
    "name": "some_tool",
    "parameters": {
      "properties": {
        "cited_claims": {
          "description": "A list of citations to be added to the response which link claims to source texts and quotes.",
          "items": {
            "properties": {
              "citation": {
                "properties": {
                  "document_chunk_id": {
                    "anyOf": [
                      {
                        "type": "string"
                      },
                      {
                        "type": "null"
                      }
                    ],
                    "default": null,
                    "description": "The id of the document node or chunk."
                  },
                  "document_name": {
                    "anyOf": [
                      {
                        "type": "string"
                      },
                      {
                        "type": "null"
                      }
                    ],
                    "default": null,
                    "description": "The name of the document."
                  },
                  "file_id": {
                    "anyOf": [
                      {
                        "type": "string"
                      },
                      {
                        "type": "null"
                      }
                    ],
                    "default": null,
                    "description": "The id of the document."
                  },
                  "page": {
                    "anyOf": [
                      {
                        "type": "integer"
                      },
                      {
                        "type": "string"
                      },
                      {
                        "type": "null"
                      }
                    ],
                    "default": null,
                    "description": "The page number, url of the webpage, etc."
                  },
                  "quote": {
                    "description": "The verbatim text to cite from a document or webpage.",
                    "type": "string"
                  },
                  "url": {
                    "anyOf": [
                      {
                        "type": "string"
                      },
                      {
                        "type": "null"
                      }
                    ],
                    "default": null,
                    "description": "The url of the webpage."
                  }
                },
                "required": [
                  "quote"
                ],
                "type": "object"
              },
              "claim": {
                "description": "The claim which is supported by the citation. Should be verbatim text from the response. A response may contain multiple claims, and thus multiple Citations.",
                "type": "string"
              }
            },
            "required": [
              "claim",
              "citation"
            ],
            "type": "object"
          },
          "type": "array"
        },
        "response": {
          "description": "The final response which contains one or more claims that need to be cited. This will be the tool's output",
          "type": "string"
        }
      },
      "required": [
        "response",
        "cited_claims"
      ],
      "type": "object"
    }
  },
  "type": "function"
}

If the nested properties are removed, there is no error. E.g.:

{
  "function": {
    "description": "some tool.",
    "name": "some_tool",
    "parameters": {
      "properties": {
        "cited_claims": {
          "description": "A list of citations to be added to the response which link claims to source texts and quotes.",
          "items": {
            "type": "string"
          },
          "type": "array"
        },
        "response": {
          "description": "The final response which contains one or more claims that need to be cited. This will be the tool's output",
          "type": "string"
        }
      },
      "required": [
        "response",
        "cited_claims"
      ],
      "type": "object"
    }
  },
  "type": "function"
}
2

It looks like this is an issue with the way that Pydantic creates JSON schemas.

When a pydantic field has a definition like some_field: str | None = None, Pydantic’s model_json_schema() will create a schema like:

{
    "anyOf": [
        {
            "type": "string"
        },
        {
            "type": "null"
        }
    ],
}

rather than

{
    "type": ["string", "null"],
}

Responses API will only work with the latter, whereas Completions API would handle either format.

Read more about why Pydantic formats in this way in this issue #7161 in pydantic’s repo on github (can’t include a link here).

1 Like