The response object

Represents a model response.

background boolean
Whether this response was run in the background.

completed_at number or null
Unix timestamp (in seconds) of when this Response was completed.
Only present when the status is completed.

conversation object
The conversation that this response belonged to. Input items and output items from this response were automatically added to this conversation.

created_at number
Unix timestamp (in seconds) of when this Response was created.

error object
An error object returned when the model fails to generate a Response. See The error object.

id string
Unique identifier for this Response.

incomplete_details object
Details about why the response is incomplete.

instructions string or array
A system (or developer) message inserted into the model's context.
When using along with previous_response_id, the instructions from a previous response will not be carried over to the next response. This makes it simple to swap out system (or developer) messages in new responses.

max_output_tokens integer
The maximum number of output tokens allowed for this response.

max_tool_calls integer
The maximum number of tool calls allowed for this response.

metadata map
Set of 16 key-value pairs that can be attached to an object. This can be useful for storing additional information about the object in a structured format, and querying for objects via API or the dashboard.
Keys are strings with a maximum length of 64 characters. Values are strings with a maximum length of 512 characters.

model string
Model ID used to generate the response, like gpt-4o or o3. OpenAI offers a wide range of models with different capabilities, performance characteristics, and price points. Refer to the model guide to browse and compare available models.

object string
The object type of this resource - always set to response.

output array
An array of content items generated by the model.

The length and order of items in the output array is dependent on the model's response.
Rather than accessing the first item in the output array and assuming it's an assistant message with the content generated by the model, you might consider using the output_text property where supported in SDKs.

output_text string
SDK Only
SDK-only convenience property that contains the aggregated text output from all output_text items in the output array, if any are present. Supported in the Python and JavaScript SDKs.

parallel_tool_calls boolean
Whether tool calls were allowed to run in parallel.

previous_response_id string
The unique ID of the previous response to the model. Use this to create multi-turn conversations. Cannot be used in conjunction with conversation.

prompt object
Reference to a prompt template and its variables.

prompt_cache_key string
Used by OpenAI to cache responses for similar requests to optimize your cache hit rates. Replaces the user field.

prompt_cache_retention string
The retention policy for the prompt cache. Set to 24h to enable extended prompt caching, which keeps cached prefixes active for longer, up to a maximum of 24 hours.

reasoning object
gpt-5 and o-series models only. Configuration options for reasoning models.

safety_identifier string
A stable identifier used to help detect users of your application that may be violating OpenAI's usage policies. The IDs should be a string that uniquely identifies each user. We recommend hashing their username or email address, in order to avoid sending us any identifying information.

service_tier string
Specifies the processing type used for serving the request.

If set to auto, then the request will be processed with the service tier configured in the Project settings. Unless otherwise configured, the Project will use default.
If set to default, then the request will be processed with the standard pricing and performance for the selected model.
If set to flex or priority, then the request will be processed with the corresponding service tier.
When not set, the default behavior is auto.
When the service_tier parameter is set, the response body will include the service_tier value based on the processing mode actually used to serve the request. This response value may be different from the value set in the parameter.

status string
The status of the response generation. One of completed, failed, in_progress, cancelled, queued, or incomplete.

temperature number
Sampling temperature used to generate the response.

`text` object
Configuration options for a text response from the model. Can be plain text or structured JSON data

tool_choice string or object
How the model should select which tool (or tools) to use when generating a response. See the tools parameter to see how to specify which tools the model can call.

tools array
An array of tools the model may call while generating a response. You can specify which tool to use by setting the tool_choice parameter.
We support the following categories of tools:

Built-in tools: Tools that are provided by OpenAI that extend the model's capabilities, like web search or file search.
MCP Tools: Integrations with third-party systems via custom MCP servers or predefined connectors such as Google Drive and SharePoint.
Function calls (custom tools): Functions that are defined by you, enabling the model to call your own code with strongly typed arguments and outputs. You can also use custom tools to call your own code.

top_logprobs integer
An integer between 0 and 20 specifying the number of most likely tokens to return at each token position, each with an associated log probability.

top_p number
An alternative to sampling with temperature, called nucleus sampling, where the model considers the results of the tokens with top_p probability mass. So 0.1 means only the tokens comprising the top 10% probability mass are considered. We generally recommend altering this or temperature but not both.

truncation string
The truncation strategy to use for the model response.

auto: If the input to this Response exceeds the model's context window size, the model will truncate the response to fit the context window by dropping items from the beginning of the conversation.
disabled (default): If the input size will exceed the context window size for a model, the request will fail with a 400 error.

usage object
Represents token usage details including input tokens, output tokens, a breakdown of output tokens, and the total tokens used.

user string
A stable identifier for your end-users. Used to boost cache hit rates by better bucketing similar requests and to help OpenAI detect and prevent abuse. This field is being replaced by safety_identifier and prompt_cache_key and will be removed in a future release.

OBJECT The response object

bash

{
  "id": "resp_67ccd3a9da748190baa7f1570fe91ac604becb25c45c1d41",
  "object": "response",
  "created_at": 1741476777,
  "status": "completed",
  "completed_at": 1741476778,
  "error": null,
  "incomplete_details": null,
  "instructions": null,
  "max_output_tokens": null,
  "model": "gpt-4o-2024-08-06",
  "output": [
    {
      "type": "message",
      "id": "msg_67ccd3acc8d48190a77525dc6de64b4104becb25c45c1d41",
      "status": "completed",
      "role": "assistant",
      "content": [
        {
          "type": "output_text",
          "text": "The image depicts a scenic landscape with a wooden boardwalk or pathway leading through lush, green grass under a blue sky with some clouds. The setting suggests a peaceful natural area, possibly a park or nature reserve. There are trees and shrubs in the background.",
          "annotations": []
        }
      ]
    }
  ],
  "parallel_tool_calls": true,
  "previous_response_id": null,
  "reasoning": {
    "effort": null,
    "summary": null
  },
  "store": true,
  "temperature": 1,
  "text": {
    "format": {
      "type": "text"
    }
  },
  "tool_choice": "auto",
  "tools": [],
  "top_p": 1,
  "truncation": "disabled",
  "usage": {
    "input_tokens": 328,
    "input_tokens_details": {
      "cached_tokens": 0
    },
    "output_tokens": 52,
    "output_tokens_details": {
      "reasoning_tokens": 0
    },
    "total_tokens": 380
  },
  "user": null,
  "metadata": {}
}

The compacted response object

Represents a compacted response.

id string
The unique identifier for the compacted response.

object string
The object type. Always response.compaction.

created_at integer
Unix timestamp (in seconds) when the compacted conversation was created.

output array
The compacted list of output items.

usage object
Represents token usage details including input tokens, output tokens, a breakdown of output tokens, and the total tokens used.

OBJECT The compacted response object

bash

{
  "id": "resp_001",
  "object": "response.compaction",
  "output": [
    {
      "type": "message",
      "role": "user",
      "content": [
        {
          "type": "input_text",
          "text": "Summarize our launch checklist from last week."
        }
      ]
    },
    {
      "type": "message",
      "role": "user",
      "content": [
        {
          "type": "input_text",
          "text": "You are performing a CONTEXT CHECKPOINT COMPACTION..."
        }
      ]
    },
    {
      "type": "compaction",
      "id": "cmp_001",
      "encrypted_content": "encrypted-summary"
    }
  ],
  "created_at": 1731459200,
  "usage": {
    "input_tokens": 42897,
    "output_tokens": 12000,
    "total_tokens": 54912
  }
}

The response object ​

text object Configuration options for a text response from the model. Can be plain text or structured JSON data ​

The compacted response object ​

The response object

`text` object
Configuration options for a text response from the model. Can be plain text or structured JSON data

The compacted response object