Represents a chat completion response returned by Claude models using the OpenAI-compatible format.

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Object Fields

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id
string
A unique identifier for the chat completion.
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choices
array
A list of chat completion choices.Each choice object contains:
  • index (integer): The index of the choice
  • message (object): The message generated by the model
    • role (string): The role (assistant)
    • content (string): The content of the message
  • finish_reason (string): The reason the model stopped (stop, length)
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created
integer
The Unix timestamp (in seconds) of when the completion was created.
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model
string
The model used for the chat completion.
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object
string
The object type, which is always chat.completion.
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usage
object
Usage statistics for the completion request.
  • completion_tokens (integer): Number of tokens in the generated completion
  • prompt_tokens (integer): Number of tokens in the prompt
  • total_tokens (integer): Total number of tokens used

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Example

{
  "id": "chatcmpl-claude-123",
  "object": "chat.completion",
  "created": 1677652288,
  "model": "claude-sonnet-4-20250514",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello! How can I help you today?"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 20,
    "completion_tokens": 10,
    "total_tokens": 30
  }
}