id: string

The unique ID of the message.

content: Array<ResponseInputText { text, type, prompt_cache_breakpoint } | ResponseOutputText { annotations, text, type, logprobs } | TextContent { text, type } | 6 more>

The content of the message

One of the following:
ResponseInputText { text, type, prompt_cache_breakpoint }

A text input to the model.

text: string

The text input to the model.

type: "input_text"

The type of the input item. Always input_text.

prompt_cache_breakpoint?: PromptCacheBreakpoint { mode }

Marks the exact end of a reusable prompt prefix. The breakpoint inherits its TTL from the request’s prompt_cache_options.ttl; the boundary is not rounded to a token block.

mode: "explicit"

The breakpoint mode. Always explicit.

ResponseOutputText { annotations, text, type, logprobs }

A text output from the model.

annotations: Array<FileCitation { file_id, filename, index, type } | URLCitation { end_index, start_index, title, 2 more } | ContainerFileCitation { container_id, end_index, file_id, 3 more } | FilePath { file_id, index, type } >

The annotations of the text output.

One of the following:
FileCitation { file_id, filename, index, type }

A citation to a file.

file_id: string

The ID of the file.

filename: string

The filename of the file cited.

index: number

The index of the file in the list of files.

type: "file_citation"

The type of the file citation. Always file_citation.

URLCitation { end_index, start_index, title, 2 more }

A citation for a web resource used to generate a model response.

end_index: number

The index of the last character of the URL citation in the message.

start_index: number

The index of the first character of the URL citation in the message.

title: string

The title of the web resource.

type: "url_citation"

The type of the URL citation. Always url_citation.

url: string

The URL of the web resource.

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ContainerFileCitation { container_id, end_index, file_id, 3 more }

A citation for a container file used to generate a model response.

container_id: string

The ID of the container file.

end_index: number

The index of the last character of the container file citation in the message.

file_id: string

The ID of the file.

filename: string

The filename of the container file cited.

start_index: number

The index of the first character of the container file citation in the message.

type: "container_file_citation"

The type of the container file citation. Always container_file_citation.

FilePath { file_id, index, type }

A path to a file.

file_id: string

The ID of the file.

index: number

The index of the file in the list of files.

type: "file_path"

The type of the file path. Always file_path.

text: string

The text output from the model.

type: "output_text"

The type of the output text. Always output_text.

logprobs?: Array<Logprob>
token: string
bytes: Array<number>
logprob: number
top_logprobs: Array<TopLogprob>
token: string
bytes: Array<number>
logprob: number
TextContent { text, type }

A text content.

text: string
type: "text"
SummaryTextContent { text, type }

A summary text from the model.

text: string

A summary of the reasoning output from the model so far.

type: "summary_text"

The type of the object. Always summary_text.

ReasoningText { text, type }

Reasoning text from the model.

text: string

The reasoning text from the model.

type: "reasoning_text"

The type of the reasoning text. Always reasoning_text.

ResponseOutputRefusal { refusal, type }

A refusal from the model.

refusal: string

The refusal explanation from the model.

type: "refusal"

The type of the refusal. Always refusal.

ResponseInputImage { detail, type, file_id, 2 more }

An image input to the model. Learn about image inputs.

detail: ImageDetail

The detail level of the image to be sent to the model. One of high, low, auto, or original. Defaults to auto.

One of the following:
"low"
"high"
"auto"
"original"
type: "input_image"

The type of the input item. Always input_image.

file_id?: string | null

The ID of the file to be sent to the model.

image_url?: string | null

The URL of the image to be sent to the model. A fully qualified URL or base64 encoded image in a data URL.

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prompt_cache_breakpoint?: PromptCacheBreakpoint { mode }

Marks the exact end of a reusable prompt prefix. The breakpoint inherits its TTL from the request’s prompt_cache_options.ttl; the boundary is not rounded to a token block.

mode: "explicit"

The breakpoint mode. Always explicit.

ComputerScreenshotContent { detail, file_id, image_url, 2 more }

A screenshot of a computer.

detail: ImageDetail

The detail level of the screenshot image to be sent to the model. One of high, low, auto, or original. Defaults to auto.

One of the following:
"low"
"high"
"auto"
"original"
file_id: string | null

The identifier of an uploaded file that contains the screenshot.

image_url: string | null

The URL of the screenshot image.

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type: "computer_screenshot"

Specifies the event type. For a computer screenshot, this property is always set to computer_screenshot.

prompt_cache_breakpoint?: PromptCacheBreakpoint { mode }

Marks the exact end of a reusable prompt prefix. The breakpoint inherits its TTL from the request’s prompt_cache_options.ttl; the boundary is not rounded to a token block.

mode: "explicit"

The breakpoint mode. Always explicit.

ResponseInputFile { type, detail, file_data, 4 more }

A file input to the model.

type: "input_file"

The type of the input item. Always input_file.

detail?: "auto" | "low" | "high"

The detail level of the file to be sent to the model. Use auto to let the system select the detail level; for GPT-5.6 and later models, auto uses high-quality rendering, which may increase input token usage. Use low for lower-cost rendering, or high to render the file at higher quality. Defaults to auto.

One of the following:
"auto"
"low"
"high"
file_data?: string

The content of the file to be sent to the model.

file_id?: string | null

The ID of the file to be sent to the model.

file_url?: string

The URL of the file to be sent to the model.

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filename?: string

The name of the file to be sent to the model.

prompt_cache_breakpoint?: PromptCacheBreakpoint { mode }

Marks the exact end of a reusable prompt prefix. The breakpoint inherits its TTL from the request’s prompt_cache_options.ttl; the boundary is not rounded to a token block.

mode: "explicit"

The breakpoint mode. Always explicit.

role: "unknown" | "user" | "assistant" | 5 more

The role of the message. One of unknown, user, assistant, system, critic, discriminator, developer, or tool.

One of the following:
"unknown"
"user"
"assistant"
"system"
"critic"
"discriminator"
"developer"
"tool"
status: "in_progress" | "completed" | "incomplete"

The status of item. One of in_progress, completed, or incomplete. Populated when items are returned via API.

One of the following:
"in_progress"
"completed"
"incomplete"
type: "message"

The type of the message. Always set to message.

phase?: "commentary" | "final_answer" | null

Labels an assistant message as intermediate commentary (commentary) or the final answer (final_answer). For models like gpt-5.3-codex and beyond, when sending follow-up requests, preserve and resend phase on all assistant messages — dropping it can degrade performance. Not used for user messages.

One of the following:
"commentary"
"final_answer"