content: Union[str, BetaResponseInputMessageContentList]

Text, image, or audio input to the model, used to generate a response. Can also contain previous assistant responses.

One of the following:
str

A text input to the model.

List[BetaResponseInputContent]
One of the following:
class BetaResponseInputText: …

A text input to the model.

text: str

The text input to the model.

type: Literal["input_text"]

The type of the input item. Always input_text.

prompt_cache_breakpoint: Optional[PromptCacheBreakpoint]

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: Literal["explicit"]

The breakpoint mode. Always explicit.

class BetaResponseInputImage: …

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

detail: BetaImageDetail

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

type: Literal["input_image"]

The type of the input item. Always input_image.

file_id: Optional[str]

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

image_url: Optional[str]

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

formaturi
prompt_cache_breakpoint: Optional[PromptCacheBreakpoint]

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: Literal["explicit"]

The breakpoint mode. Always explicit.

class BetaResponseInputFile: …

A file input to the model.

type: Literal["input_file"]

The type of the input item. Always input_file.

detail: Optional[Literal["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: Optional[str]

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

file_id: Optional[str]

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

file_url: Optional[str]

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

formaturi
filename: Optional[str]

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

prompt_cache_breakpoint: Optional[PromptCacheBreakpoint]

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: Literal["explicit"]

The breakpoint mode. Always explicit.

role: Literal["user", "assistant", "system", "developer"]

The role of the message input. One of user, assistant, system, or developer.

One of the following:
"user"
"assistant"
"system"
"developer"
phase: Optional[Literal["commentary", "final_answer"]]

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"
type: Optional[Literal["message"]]

The type of the message input. Always message.