Cannot bind response_format.json_schema.schema into json.Marshaler field for structured outputs in chat/completions

[AyushSawant18588]

I’m building a service-to-service integration that receives Chat Completion requests and binds them directly into the Go client’s ChatCompletionRequest struct using Gin:

var req openai.ChatCompletionRequest
if err := c.ShouldBindJSON(&req); err != nil {
    // handle binding error
}

The struct for the JSON Schema portion is:

go-openai/chat.go

Line 220 in c125ae2

Schema json.Marshaler `json:"schema"`

Because json.Marshaler only implements MarshalJSON() and not UnmarshalJSON(), any nested object under "schema" fails to bind.

Reproduction
Send an HTTP POST with a body like:

{
  "model": "llama3-1b",
  "messages": [
    { "role": "system", "content": "You are a helpful math tutor." },
    { "role": "user",   "content": "solve 8x + 31 = 2" }
  ],
  "response_format": {
    "type": "json_schema",
    "json_schema": {
      "name":   "math_response",
      "strict": true,
      "schema": {
        "type": "object",
        "properties": {
          "steps": {
            "type": "array",
            "items": {
              "type": "object",
              "properties": {
                "explanation": { "type": "string" },
                "output":      { "type": "string" }
              },
              "required": ["explanation","output"],
              "additionalProperties": false
            }
          },
          "final_answer": { "type": "string" }
        },
        "required": ["steps","final_answer"],
        "additionalProperties": false
      }
    }
  }
}

Actual error:

json: cannot unmarshal object into Go struct field 
ChatCompletionResponseFormatJSONSchema.response_format.json_schema.schema of type json.Marshaler

Expected Behavior:
The request should bind successfully into openai.ChatCompletionRequest without modifying the client library.
I can include a full JSON Schema object under "schema" and have it round-trip through Gin’s ShouldBindJSON into the existing json.Marshaler field.

Question

1. Is there a valid JSON payload I can send right now—without changing the client’s struct definition—that will satisfy ShouldBindJSON and allow my handler to bind into ChatCompletionResponseFormatJSONSchema.Schema? If so, please provide an example.

2. Else, Can we update the ChatCompletionResponseFormatJSONSchema struct (in configuration or code) so that this bind is successful?

Thank you!

[AyushSawant18588]

@eiixy @sashabaranov Can you please help?