Claude Platform Docs

消息

创建消息
beta.messages.create(**kwargs) -> BetaMessage
POST/v1/messages

发送包含文本和/或图像内容的结构化输入消息列表,模型将生成对话中的下一条消息。

计算消息中的令牌数
beta.messages.count_tokens(**kwargs) -> BetaMessageTokensCount
POST/v1/messages/count_tokens

计算消息中的令牌数量。

Models
class BetaAdvisorMessageIterationUsage: type: "advisor_message"; cache_creation; cache_creation_input_tokens; ... # 4 more

Token usage for an advisor sub-inference iteration.

class BetaAdvisorRedactedResultBlock: type: "advisor_redacted_result"; encrypted_content; stop_reason
type: Literal["advisor_redacted_result"]
defaultadvisor_redacted_result
encrypted_content: str

Opaque blob containing the advisor's output. Round-trip verbatim; do not inspect or modify.

stop_reason: Optional[str]

The advisor sub-inference's stop reason (same values as the top-level message stop_reason).

class BetaAdvisorRedactedResultBlockParam: type: "advisor_redacted_result"; encrypted_content; stop_reason
type: Literal["advisor_redacted_result"]
encrypted_content: str

Opaque blob produced by a prior response; must be round-tripped verbatim.

stop_reason: Optional[str]
class BetaAdvisorResultBlock: type: "advisor_result"; stop_reason; text
type: Literal["advisor_result"]
defaultadvisor_result
stop_reason: Optional[str]

The advisor sub-inference's stop reason (same values as the top-level message stop_reason). max_tokens indicates the advisor's output was truncated at the tool's max_tokens value or the advisor model's policy cap.

text: str
class BetaAdvisorResultBlockParam: type: "advisor_result"; text; stop_reason
type: Literal["advisor_result"]
text: str
stop_reason: Optional[str]
class BetaAdvisorTool20260301: type: "advisor_20260301"; model; name; ... # 7 more
class BetaAdvisorToolResultBlock: type: "advisor_tool_result"; content; tool_use_id
class BetaAdvisorToolResultBlockParam: type: "advisor_tool_result"; content; tool_use_id; cache_control
class BetaAdvisorToolResultError: type: "advisor_tool_result_error"; error_code
type: Literal["advisor_tool_result_error"]
defaultadvisor_tool_result_error
error_code: Literal["max_uses_exceeded", "prompt_too_long", "too_many_requests", 4 more]
One of the following:
"max_uses_exceeded"
"prompt_too_long"
"too_many_requests"
"overloaded"
"unavailable"
"execution_time_exceeded"
"model_not_found"
class BetaAdvisorToolResultErrorParam: type: "advisor_tool_result_error"; error_code
type: Literal["advisor_tool_result_error"]
error_code: Literal["max_uses_exceeded", "prompt_too_long", "too_many_requests", 4 more]
One of the following:
"max_uses_exceeded"
"prompt_too_long"
"too_many_requests"
"overloaded"
"unavailable"
"execution_time_exceeded"
"model_not_found"
class BetaAllThinkingTurns: type: "all"
type: Literal["all"]
class BetaBase64ImageSource: type: "base64"; data; media_type
type: Literal["base64"]
data: str
formatbyte
media_type: Literal["image/jpeg", "image/png", "image/gif", "image/webp"]
One of the following:
"image/jpeg"
"image/png"
"image/gif"
"image/webp"
class BetaBase64PDFSource: type: "base64"; data; media_type
type: Literal["base64"]
data: str
formatbyte
media_type: Literal["application/pdf"]
class BetaBashCodeExecutionOutputBlock: type: "bash_code_execution_output"; file_id
type: Literal["bash_code_execution_output"]
defaultbash_code_execution_output
file_id: str
class BetaBashCodeExecutionOutputBlockParam: type: "bash_code_execution_output"; file_id
type: Literal["bash_code_execution_output"]
file_id: str
class BetaBashCodeExecutionResultBlock: type: "bash_code_execution_result"; content; return_code; ... # 2 more
type: Literal["bash_code_execution_result"]
defaultbash_code_execution_result
type: Literal["bash_code_execution_output"]
defaultbash_code_execution_output
file_id: str
return_code: int
stderr: str
stdout: str
class BetaBashCodeExecutionResultBlockParam: type: "bash_code_execution_result"; content; return_code; ... # 2 more
type: Literal["bash_code_execution_result"]
type: Literal["bash_code_execution_output"]
file_id: str
return_code: int
stderr: str
stdout: str
class BetaBashCodeExecutionToolResultBlock: type: "bash_code_execution_tool_result"; content; tool_use_id
class BetaBashCodeExecutionToolResultBlockParam: type: "bash_code_execution_tool_result"; content; tool_use_id; cache_control
class BetaBashCodeExecutionToolResultError: type: "bash_code_execution_tool_result_error"; error_code
type: Literal["bash_code_execution_tool_result_error"]
defaultbash_code_execution_tool_result_error
error_code: Literal["invalid_tool_input", "unavailable", "too_many_requests", 2 more]
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
"output_file_too_large"
class BetaBashCodeExecutionToolResultErrorParam: type: "bash_code_execution_tool_result_error"; error_code
type: Literal["bash_code_execution_tool_result_error"]
error_code: Literal["invalid_tool_input", "unavailable", "too_many_requests", 2 more]
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
"output_file_too_large"
type BetaBrowserClickTarget = ...

Where to act: either a viewport coordinate or an element reference.

One of the following:
class BetaBrowserCoordinateTarget: type: "coordinate"; x; y

A point in the browser viewport, in viewport pixels (the same frame as a full-viewport screenshot).

type: Literal["coordinate"]
x: int

Pixels from the left edge of the viewport.

minimum0
y: int

Pixels from the top edge of the viewport.

minimum0
class BetaBrowserRefTarget: type: "ref"; ref

An element on the page, identified by a reference from a prior read_page or find result. References are scoped to the tab that produced them and become stale after navigation or a major re-render.

type: Literal["ref"]
ref: str

An element reference (e.g. "ref_7") returned by a prior read_page or find result.

class BetaBrowserCloseTabConfig: defer_loading; enabled

close_tab's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserCloseTabInput: tab_id

Close the tab with the given tab_id.

tab_id: str

The tab to close.

class BetaBrowserCloseTabToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserCoordinateTarget: type: "coordinate"; x; y

A point in the browser viewport, in viewport pixels (the same frame as a full-viewport screenshot).

type: Literal["coordinate"]
x: int

Pixels from the left edge of the viewport.

minimum0
y: int

Pixels from the top edge of the viewport.

minimum0
class BetaBrowserDoubleClickConfig: defer_loading; enabled

double_click's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserDoubleClickInput: target; modifiers; tab_id

Double left-click at a viewport coordinate or on an element by reference.

class BetaBrowserDoubleClickToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserFileUploadConfig: defer_loading; enabled

file_upload's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserFileUploadInput: target; document_ids; paths; tab_id

Set the value of a file-input element to one or more files. The target must be an element reference; at least one of paths or document_ids is required.

An element on the page, identified by a reference from a prior read_page or find result. References are scoped to the tab that produced them and become stale after navigation or a major re-render.

type: Literal["ref"]
ref: str

An element reference (e.g. "ref_7") returned by a prior read_page or find result.

document_ids: Optional[List[str]]

References to files the harness has staged, for deployments where the browser executor cannot read the caller's filesystem.

minItems1
paths: Optional[List[str]]

File paths on the browser executor's filesystem.

minItems1
tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserFileUploadToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserFindConfig: defer_loading; enabled

find's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserFindInput: query; tab_id

Find elements matching a natural-language description (e.g. "search bar", "add to cart button") and return up to 20 matches with element references.

query: str

Natural-language description of the element(s) to find.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserFindToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserFormInputConfig: defer_loading; enabled

form_input's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserFormInputInput: target; value; tab_id

Set the value of a form element (input, textarea, select, checkbox). Use a boolean for checkboxes, an option value or text for selects.

An element on the page, identified by a reference from a prior read_page or find result. References are scoped to the tab that produced them and become stale after navigation or a major re-render.

type: Literal["ref"]
ref: str

An element reference (e.g. "ref_7") returned by a prior read_page or find result.

The value to set.

One of the following:
str
float
bool
tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserFormInputToolUseBlock: type: "tool_use"; id; input; ... # 3 more
type BetaBrowserFormInputValue = Union[str, float, bool]
One of the following:
str
float
bool
class BetaBrowserGetPageTextConfig: defer_loading; enabled

get_page_text's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserGetPageTextInput: tab_id

Return the page's visible text content as plain text, prioritizing article content. Suited to articles, documentation, and other text-heavy pages.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserGetPageTextToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserHoldKeyConfig: defer_loading; enabled

hold_key's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserHoldKeyInput: duration; text; tab_id

Hold a key or key chord down for a duration, then release it. Uses the same key names and "+" chord syntax as the key action.

duration: float

Seconds to hold the key down (maximum 30).

minimum0
maximum30
text: str

The key or chord to hold.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserHoldKeyToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserHoverConfig: defer_loading; enabled

hover's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserHoverInput: target; tab_id

Move the cursor to a coordinate or element without clicking.

class BetaBrowserHoverToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserJavascriptExecConfig: defer_loading; enabled

javascript_exec's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserJavascriptExecInput: text; tab_id

Execute JavaScript in the page context and return the value of the last expression. The code runs with access to the DOM, window, and page variables. Write the expression you want evaluated — do NOT use return.

text: str

JavaScript to execute in the page context.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserJavascriptExecToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserKeyConfig: defer_loading; enabled

key's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserKeyInput: text; repeat; tab_id

Press a key or key chord. Use "+" to combine modifiers with a key (e.g. "ctrl+a", "cmd+shift+p") and space to sequence presses (e.g. "Backspace Backspace Delete"). Common names like "Return", "Tab", "Escape", "BackSpace" are supported.

text: str

The key, chord, or space-separated sequence to press.

repeat: Optional[int]

Number of times to repeat. Default 1.

minimum1
maximum100
tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserKeyToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserLeftClickConfig: defer_loading; enabled

left_click's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserLeftClickDragConfig: defer_loading; enabled

left_click_drag's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserLeftClickDragInput: from_; target; tab_id

Press at from, drag to target, release. Both must be coordinate targets.

A point in the browser viewport, in viewport pixels (the same frame as a full-viewport screenshot).

type: Literal["coordinate"]
x: int

Pixels from the left edge of the viewport.

minimum0
y: int

Pixels from the top edge of the viewport.

minimum0

A point in the browser viewport, in viewport pixels (the same frame as a full-viewport screenshot).

type: Literal["coordinate"]
x: int

Pixels from the left edge of the viewport.

minimum0
y: int

Pixels from the top edge of the viewport.

minimum0
tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserLeftClickDragToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserLeftClickInput: target; modifiers; tab_id

Left-click at a viewport coordinate or on an element by reference.

class BetaBrowserLeftClickToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserLeftMouseDownConfig: defer_loading; enabled

left_mouse_down's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserLeftMouseDownInput: target; tab_id

Press and hold the left mouse button at a viewport coordinate. Pair with left_mouse_up to perform a custom drag.

A point in the browser viewport, in viewport pixels (the same frame as a full-viewport screenshot).

type: Literal["coordinate"]
x: int

Pixels from the left edge of the viewport.

minimum0
y: int

Pixels from the top edge of the viewport.

minimum0
tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserLeftMouseDownToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserLeftMouseUpConfig: defer_loading; enabled

left_mouse_up's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserLeftMouseUpInput: target; tab_id

Release the left mouse button at a viewport coordinate.

A point in the browser viewport, in viewport pixels (the same frame as a full-viewport screenshot).

type: Literal["coordinate"]
x: int

Pixels from the left edge of the viewport.

minimum0
y: int

Pixels from the top edge of the viewport.

minimum0
tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserLeftMouseUpToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserListTabsConfig: defer_loading; enabled

list_tabs's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserListTabsInput: ...

List all open tabs with each tab's tab_id, title, and URL.

class BetaBrowserListTabsToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserMiddleClickConfig: defer_loading; enabled

middle_click's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserMiddleClickInput: target; modifiers; tab_id

Middle-click at a viewport coordinate or on an element by reference.

class BetaBrowserMiddleClickToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserMouseMoveConfig: defer_loading; enabled

mouse_move's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserMouseMoveInput: target; tab_id

Move the pointer to a viewport coordinate without clicking.

A point in the browser viewport, in viewport pixels (the same frame as a full-viewport screenshot).

type: Literal["coordinate"]
x: int

Pixels from the left edge of the viewport.

minimum0
y: int

Pixels from the top edge of the viewport.

minimum0
tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserMouseMoveToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserNavigateConfig: defer_loading; enabled

navigate's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserNavigateInput: url; tab_id

Navigate to a URL, or go back/forward/reload in history. The protocol may be omitted (defaults to https://).

url: str

The URL to navigate to, or "back" / "forward" / "reload" for history navigation.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserNavigateToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserNewTabConfig: defer_loading; enabled

new_tab's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserNewTabInput: ...

Open a new empty tab and return its tab_id.

class BetaBrowserNewTabToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserReadConsoleConfig: defer_loading; enabled

read_console's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserReadConsoleInput: tab_id

Return console output (log entries, errors, warnings) accumulated since the driver attached to the tab and since the last read, one line per entry. An empty result does not mean no traffic for a tab that predates attach.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserReadConsoleToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserReadNetworkConfig: defer_loading; enabled

read_network's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserReadNetworkInput: tab_id

Return the network requests (method, URL, status, MIME type, timing) recorded since the driver attached to the tab and since the last read, one line per entry. An empty result does not mean no traffic for a tab that predates attach.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserReadNetworkToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserReadPageConfig: defer_loading; enabled

read_page's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

type BetaBrowserReadPageFilter = Literal["all", "interactive"]
One of the following:
"all"
"interactive"
class BetaBrowserReadPageInput: depth; filter; ref; tab_id

Return a structured accessibility tree of the page (or the subtree rooted at ref), with element references like [ref_7] that can be used as targets on later actions. Output is capped at 50,000 characters — narrow with ref or a smaller depth when exceeded.

depth: Optional[int]

Maximum tree depth. Default 15.

minimum1
filter: Optional[BetaBrowserReadPageFilter]

Which elements to include. Omitted: every visible element. "interactive": interactive elements only. "all": additionally includes off-viewport elements.

One of the following:
"all"
"interactive"
ref: Optional[str]

Element reference to read a subtree from. Omit to read from the page root.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserReadPageToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserRefTarget: type: "ref"; ref

An element on the page, identified by a reference from a prior read_page or find result. References are scoped to the tab that produced them and become stale after navigation or a major re-render.

type: Literal["ref"]
ref: str

An element reference (e.g. "ref_7") returned by a prior read_page or find result.

class BetaBrowserRightClickConfig: defer_loading; enabled

right_click's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserRightClickInput: target; modifiers; tab_id

Right-click at a viewport coordinate or on an element by reference.

class BetaBrowserRightClickToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserScreenshotConfig: defer_loading; enabled

screenshot's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserScreenshotInput: tab_id

Capture the current browser viewport.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserScreenshotToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserScrollConfig: defer_loading; enabled

scroll's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

type BetaBrowserScrollDirection = Literal["up", "down", "left", "right"]
One of the following:
"up"
"down"
"left"
"right"
class BetaBrowserScrollInput: scroll_direction; target; scroll_amount; tab_id

Scroll at a viewport position. target must be a coordinate target.

scroll_direction: BetaBrowserScrollDirection
One of the following:
"up"
"down"
"left"
"right"

A point in the browser viewport, in viewport pixels (the same frame as a full-viewport screenshot).

type: Literal["coordinate"]
x: int

Pixels from the left edge of the viewport.

minimum0
y: int

Pixels from the top edge of the viewport.

minimum0
scroll_amount: Optional[int]

Scroll-wheel notches (1–10). Default 3.

minimum1
maximum10
tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserScrollToConfig: defer_loading; enabled

scroll_to's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserScrollToInput: target; tab_id

Scroll an element into view.

An element on the page, identified by a reference from a prior read_page or find result. References are scoped to the tab that produced them and become stale after navigation or a major re-render.

type: Literal["ref"]
ref: str

An element reference (e.g. "ref_7") returned by a prior read_page or find result.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserScrollToToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserScrollToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserStateBlockParam: type: "browser_state"; tabs; cache_control; state_changes

The caller's browser state after a browser toolset member call — the full inventory of open tabs, which tab is active, and any side effects (tabs opened, download state changes) the call produced.

At most one per tool_result, only on a non-error result answering a browser toolset member tool_use. The server renders the model-visible text from it; the model never sees the raw fields.

type BetaBrowserStateChange = ...
One of the following:
class BetaBrowserStateChangeDownloadCompleted: type: "download_completed"; download_id; url; ... # 2 more

A file download that finished during this call, reported with the same download_id as its download_started — or without a prior download_started, when the download finished during the call that started it (at most one state change per download_id per result).

type: Literal["download_completed"]
download_id: str

The caller-assigned identifier for this download, stable across the state changes reporting it.

minLength1
maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
url: str

The final post-redirect URL the download was served from.

maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
path: Optional[str]

Where the executor saved the file, on the executor's filesystem. Only included when another tool in the same environment can read the file at that path.

maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
size_bytes: Optional[int]

The completed download's size.

minimum0
class BetaBrowserStateChangeDownloadFailed: type: "download_failed"; download_id; url; error

A file download that failed — or was cancelled — during this call.

type: Literal["download_failed"]
download_id: str

The caller-assigned identifier for this download, stable across the state changes reporting it.

minLength1
maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
url: str

The final post-redirect URL the download was served from.

maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
error: Optional[str]

The failure or cancellation detail, when known.

maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
class BetaBrowserStateChangeDownloadStarted: type: "download_started"; download_id; url

A file download that started during this call.

type: Literal["download_started"]
download_id: str

The caller-assigned identifier for this download, stable across the state changes reporting it.

minLength1
maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
url: str

The final post-redirect URL the download was served from.

maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
class BetaBrowserStateChangeTabOpened: type: "tab_opened"; tab_id

A tab this call's execution opened that remains open at its end — the creation delta of the tabs inventory, not an event log.

Carries only the tab_id; the tab's title and url live on its tabs entry, which must include the same tab_id. A tab opened during a failed call gets no deferred tab_opened; it simply appears in the next result's tabs inventory.

type: Literal["tab_opened"]
tab_id: str

The tab_id of the opened tab, present in tabs.

minLength1
maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
class BetaBrowserStateTabEntry: tab_id; title; url; active

One open browser tab reported in a browser_state block's tabs inventory.

tab_id is the caller-assigned identifier for the tab; title and url describe the page the tab is currently showing and may be empty strings (a blank tab legitimately has both empty). active marks the tab that is active after this call; whenever tabs is non-empty, exactly one entry is marked.

tab_id: str

The caller-assigned identifier for this tab, unique within the inventory.

minLength1
maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
title: str

The title of the page the tab is showing. May be empty.

maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
url: str

The URL of the page the tab is showing. May be empty.

maxLength4096
pattern^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
active: Optional[bool]

Whether this tab is the active tab after this call. Whenever tabs is non-empty, exactly one entry is marked active: true.

class BetaBrowserSwitchTabConfig: defer_loading; enabled

switch_tab's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserSwitchTabInput: tab_id

Make the tab with the given tab_id the active tab — the tab that actions without a tab_id apply to.

tab_id: str

The tab to switch to.

class BetaBrowserSwitchTabToolUseBlock: type: "tool_use"; id; input; ... # 3 more
type BetaBrowserToolUseBlock = ...
One of the following:
class BetaBrowserToolset20260801: type: "browser_toolset_20260801"; cache_control; configs

The browser toolset: a single tools[] entry (carrying no name) that declares the browser tool family. The model is served the family's tool with any members disabled via configs removed from its schema.

type: Literal["browser_toolset_20260801"]
cache_control: Optional[BetaCacheControlEphemeral]

Create a cache control breakpoint at this content block.

type: Literal["ephemeral"]
ttl: Optional[Literal["5m", "1h"]]

The time-to-live for the cache control breakpoint.

This may be one the following values:

  • 5m: 5 minutes
  • 1h: 1 hour

Defaults to 5m. See prompt caching pricing for details.

One of the following:
"5m"
"1h"
configs: Optional[BetaBrowserToolsetConfigs]

Sparse per-member overrides, keyed by member name. Absent, null, and {} are equivalent; a member's defaults apply wherever its key is absent.

class BetaBrowserToolsetConfigs: type; close_tab; double_click; ... # 28 more

Per-member configuration for browser_toolset_20260801: one optional field per member tool, keyed by the member name — the same name the member's tool_use blocks carry. Every member is an accepted key, and a member's defaults apply wherever its key is absent. Unknown keys are rejected: the field set is this toolset version's complete member set.

class BetaBrowserTripleClickConfig: defer_loading; enabled

triple_click's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserTripleClickInput: target; modifiers; tab_id

Triple left-click at a viewport coordinate or on an element by reference (typically selects a line or paragraph).

class BetaBrowserTripleClickToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserTypeConfig: defer_loading; enabled

type's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserTypeInput: text; tab_id

Type a literal string at the current focus.

text: str

The text to type.

tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserTypeToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserWaitConfig: defer_loading; enabled

wait's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserWaitInput: duration; tab_id

Pause for the given duration.

duration: float

Seconds to wait (maximum 30).

minimum0
maximum30
tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserWaitToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaBrowserZoomConfig: defer_loading; enabled

zoom's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaBrowserZoomInput: region; tab_id

Return a cropped screenshot of the given viewport region, scaled up for closer inspection — useful for small icons, buttons, or text. Coordinates are in the same viewport-pixel space as a full screenshot.

region: List[int]

[x0, y0, x1, y1] in viewport pixels.

minItems4
maxItems4
tab_id: Optional[str]

Tab to act on. Defaults to the active tab when omitted.

class BetaBrowserZoomToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaCacheControlEphemeral: type: "ephemeral"; ttl
type: Literal["ephemeral"]
ttl: Optional[Literal["5m", "1h"]]

The time-to-live for the cache control breakpoint.

This may be one the following values:

  • 5m: 5 minutes
  • 1h: 1 hour

Defaults to 5m. See prompt caching pricing for details.

One of the following:
"5m"
"1h"
class BetaCacheCreation: ephemeral_1h_input_tokens; ephemeral_5m_input_tokens
ephemeral_1h_input_tokens: int

The number of input tokens used to create the 1 hour cache entry.

default0
minimum0
ephemeral_5m_input_tokens: int

The number of input tokens used to create the 5 minute cache entry.

default0
minimum0
class BetaCacheMissMessagesChanged: type: "messages_changed"; cache_missed_input_tokens
type: Literal["messages_changed"]
defaultmessages_changed
cache_missed_input_tokens: int

Approximate number of input tokens that would have been read from cache had the prefix matched the previous request.

class BetaCacheMissModelChanged: type: "model_changed"; cache_missed_input_tokens
type: Literal["model_changed"]
defaultmodel_changed
cache_missed_input_tokens: int

Approximate number of input tokens that would have been read from cache had the prefix matched the previous request.

class BetaCacheMissPreviousMessageNotFound: type: "previous_message_not_found"
type: Literal["previous_message_not_found"]
defaultprevious_message_not_found
type BetaCacheMissReason = ...
One of the following:
class BetaCacheMissSystemChanged: type: "system_changed"; cache_missed_input_tokens
type: Literal["system_changed"]
defaultsystem_changed
cache_missed_input_tokens: int

Approximate number of input tokens that would have been read from cache had the prefix matched the previous request.

class BetaCacheMissToolsChanged: type: "tools_changed"; cache_missed_input_tokens
type: Literal["tools_changed"]
defaulttools_changed
cache_missed_input_tokens: int

Approximate number of input tokens that would have been read from cache had the prefix matched the previous request.

class BetaCacheMissUnavailable: type: "unavailable"
type: Literal["unavailable"]
defaultunavailable
class BetaCitationCharLocation: type: "char_location"; cited_text; document_index; ... # 4 more
type: Literal["char_location"]
defaultchar_location
cited_text: str
document_index: int
minimum0
document_title: Optional[str]
end_char_index: int
file_id: Optional[str]
start_char_index: int
minimum0
class BetaCitationCharLocationParam: type: "char_location"; cited_text; document_index; ... # 3 more
type: Literal["char_location"]
cited_text: str
document_index: int
minimum0
document_title: Optional[str]
minLength1
maxLength500
end_char_index: int
start_char_index: int
minimum0
class BetaCitationConfig: enabled
enabled: bool
defaultfalse
class BetaCitationContentBlockLocation: type: "content_block_location"; cited_text; document_index; ... # 4 more
type: Literal["content_block_location"]
defaultcontent_block_location
cited_text: str

The full text of the cited block range, concatenated.

Always equals the contents of content[start_block_index:end_block_index] joined together. The text block is the minimal citable unit; this field is never a substring of a single block. Not counted toward output tokens, and not counted toward input tokens when sent back in subsequent turns.

document_index: int
minimum0
document_title: Optional[str]
end_block_index: int

Exclusive 0-based end index of the cited block range in the source's content array.

Always greater than start_block_index; a single-block citation has end_block_index = start_block_index + 1.

file_id: Optional[str]
start_block_index: int

0-based index of the first cited block in the source's content array.

minimum0
class BetaCitationContentBlockLocationParam: type: "content_block_location"; cited_text; document_index; ... # 3 more
type: Literal["content_block_location"]
cited_text: str

The full text of the cited block range, concatenated.

Always equals the contents of content[start_block_index:end_block_index] joined together. The text block is the minimal citable unit; this field is never a substring of a single block. Not counted toward output tokens, and not counted toward input tokens when sent back in subsequent turns.

document_index: int
minimum0
document_title: Optional[str]
minLength1
maxLength500
end_block_index: int

Exclusive 0-based end index of the cited block range in the source's content array.

Always greater than start_block_index; a single-block citation has end_block_index = start_block_index + 1.

start_block_index: int

0-based index of the first cited block in the source's content array.

minimum0
class BetaCitationPageLocation: type: "page_location"; cited_text; document_index; ... # 4 more
type: Literal["page_location"]
defaultpage_location
cited_text: str
document_index: int
minimum0
document_title: Optional[str]
end_page_number: int
file_id: Optional[str]
start_page_number: int
minimum1
class BetaCitationPageLocationParam: type: "page_location"; cited_text; document_index; ... # 3 more
type: Literal["page_location"]
cited_text: str
document_index: int
minimum0
document_title: Optional[str]
minLength1
maxLength500
end_page_number: int
start_page_number: int
minimum1
class BetaCitationSearchResultLocation: type: "search_result_location"; cited_text; end_block_index; ... # 4 more
type: Literal["search_result_location"]
defaultsearch_result_location
cited_text: str

The full text of the cited block range, concatenated.

Always equals the contents of content[start_block_index:end_block_index] joined together. The text block is the minimal citable unit; this field is never a substring of a single block. Not counted toward output tokens, and not counted toward input tokens when sent back in subsequent turns.

end_block_index: int

Exclusive 0-based end index of the cited block range in the source's content array.

Always greater than start_block_index; a single-block citation has end_block_index = start_block_index + 1.

search_result_index: int

0-based index of the cited search result among all search_result content blocks in the request, in the order they appear across messages and tool results.

Counted separately from document_index; server-side web search results are not included in this count.

minimum0
source: str
start_block_index: int

0-based index of the first cited block in the source's content array.

minimum0
title: Optional[str]
class BetaCitationSearchResultLocationParam: type: "search_result_location"; cited_text; end_block_index; ... # 4 more
type: Literal["search_result_location"]
cited_text: str

The full text of the cited block range, concatenated.

Always equals the contents of content[start_block_index:end_block_index] joined together. The text block is the minimal citable unit; this field is never a substring of a single block. Not counted toward output tokens, and not counted toward input tokens when sent back in subsequent turns.

end_block_index: int

Exclusive 0-based end index of the cited block range in the source's content array.

Always greater than start_block_index; a single-block citation has end_block_index = start_block_index + 1.

search_result_index: int

0-based index of the cited search result among all search_result content blocks in the request, in the order they appear across messages and tool results.

Counted separately from document_index; server-side web search results are not included in this count.

minimum0
source: str
start_block_index: int

0-based index of the first cited block in the source's content array.

minimum0
title: Optional[str]
class BetaCitationWebSearchResultLocationParam: type: "web_search_result_location"; cited_text; encrypted_index; ... # 2 more
type: Literal["web_search_result_location"]
cited_text: str
encrypted_index: str
title: Optional[str]
minLength1
maxLength512
url: str
minLength1
class BetaCitationsConfigParam: enabled
enabled: Optional[bool]
class BetaCitationsDelta: type: "citations_delta"; citation
class BetaCitationsWebSearchResultLocation: type: "web_search_result_location"; cited_text; encrypted_index; ... # 2 more
type: Literal["web_search_result_location"]
defaultweb_search_result_location
cited_text: str
encrypted_index: str
title: Optional[str]
maxLength512
url: str
class BetaClearThinking20251015Edit: type: "clear_thinking_20251015"; keep
type: Literal["clear_thinking_20251015"]
keep: Optional[Keep]

Number of most recent assistant turns to keep thinking blocks for. Older turns will have their thinking blocks removed.

One of the following:
class BetaThinkingTurns: type: "thinking_turns"; value
type: Literal["thinking_turns"]
value: int
minimum1
class BetaAllThinkingTurns: type: "all"
type: Literal["all"]
"all"
class BetaClearThinking20251015EditResponse: type: "clear_thinking_20251015"; cleared_input_tokens; cleared_thinking_turns
type: Literal["clear_thinking_20251015"]

The type of context management edit applied.

defaultclear_thinking_20251015
cleared_input_tokens: int

Number of input tokens cleared by this edit.

minimum0
cleared_thinking_turns: int

Number of thinking turns that were cleared.

minimum0
class BetaClearToolUses20250919Edit: type: "clear_tool_uses_20250919"; clear_at_least; clear_tool_inputs; ... # 3 more
class BetaClearToolUses20250919EditResponse: type: "clear_tool_uses_20250919"; cleared_input_tokens; cleared_tool_uses
type: Literal["clear_tool_uses_20250919"]

The type of context management edit applied.

defaultclear_tool_uses_20250919
cleared_input_tokens: int

Number of input tokens cleared by this edit.

minimum0
cleared_tool_uses: int

Number of tool uses that were cleared.

minimum0
class BetaCodeExecutionOutputBlock: type: "code_execution_output"; file_id
type: Literal["code_execution_output"]
defaultcode_execution_output
file_id: str
class BetaCodeExecutionOutputBlockParam: type: "code_execution_output"; file_id
type: Literal["code_execution_output"]
file_id: str
class BetaCodeExecutionResultBlock: type: "code_execution_result"; content; return_code; ... # 2 more
type: Literal["code_execution_result"]
defaultcode_execution_result
type: Literal["code_execution_output"]
defaultcode_execution_output
file_id: str
return_code: int
stderr: str
stdout: str
class BetaCodeExecutionResultBlockParam: type: "code_execution_result"; content; return_code; ... # 2 more
type: Literal["code_execution_result"]
type: Literal["code_execution_output"]
file_id: str
return_code: int
stderr: str
stdout: str
class BetaCodeExecutionTool20250522: type: "code_execution_20250522"; name; allowed_callers; ... # 3 more
class BetaCodeExecutionTool20250825: type: "code_execution_20250825"; name; allowed_callers; ... # 3 more
class BetaCodeExecutionTool20260120: type: "code_execution_20260120"; name; allowed_callers; ... # 3 more

Code execution tool with REPL state persistence (daemon mode + gVisor checkpoint).

class BetaCodeExecutionTool20260521: type: "code_execution_20260521"; name; allowed_callers; ... # 3 more

Code execution tool with REPL state persistence.

class BetaCodeExecutionToolResultBlock: type: "code_execution_tool_result"; content; tool_use_id
type: Literal["code_execution_tool_result"]
defaultcode_execution_tool_result
One of the following:
tool_use_id: str
pattern^srvtoolu_[a-zA-Z0-9_]+$
type BetaCodeExecutionToolResultBlockContent = ...
One of the following:
class BetaCodeExecutionToolResultBlockParam: type: "code_execution_tool_result"; content; tool_use_id; cache_control
type: Literal["code_execution_tool_result"]
One of the following:
tool_use_id: str
pattern^srvtoolu_[a-zA-Z0-9_]+$
cache_control: Optional[BetaCacheControlEphemeral]

Create a cache control breakpoint at this content block.

type: Literal["ephemeral"]
ttl: Optional[Literal["5m", "1h"]]

The time-to-live for the cache control breakpoint.

This may be one the following values:

  • 5m: 5 minutes
  • 1h: 1 hour

Defaults to 5m. See prompt caching pricing for details.

One of the following:
"5m"
"1h"
type BetaCodeExecutionToolResultBlockParamContent = ...
One of the following:
class BetaCodeExecutionToolResultError: type: "code_execution_tool_result_error"; error_code
type: Literal["code_execution_tool_result_error"]
defaultcode_execution_tool_result_error
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
type BetaCodeExecutionToolResultErrorCode = Literal["invalid_tool_input", "unavailable", "too_many_requests", "execution_time_exceeded"]
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
class BetaCodeExecutionToolResultErrorParam: type: "code_execution_tool_result_error"; error_code
type: Literal["code_execution_tool_result_error"]
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
class BetaCompact20260112Edit: type: "compact_20260112"; instructions; pause_after_compaction; trigger

Automatically compact older context when reaching the configured trigger threshold.

type: Literal["compact_20260112"]
instructions: Optional[str]

Additional instructions for summarization.

pause_after_compaction: Optional[bool]

Whether to pause after compaction and return the compaction block to the user.

trigger: Optional[BetaInputTokensTrigger]

When to trigger compaction. Defaults to 150000 input tokens.

type: Literal["input_tokens"]
value: int
minimum1
class BetaCompactionBlock: type: "compaction"; content; encrypted_content; ... # 2 more

A compaction block returned when autocompact is triggered.

When content is None, it indicates the compaction failed to produce a valid summary (e.g., malformed output from the model). Clients may round-trip compaction blocks with null content; the server treats them as no-ops.

class BetaCompactionBlockParam: type: "compaction"; cache_control; content; ... # 3 more

A compaction block containing summary of previous context.

Users should round-trip these blocks from responses to subsequent requests to maintain context across compaction boundaries.

When content is None, the block represents a failed compaction. The server treats these as no-ops. Empty string content is not allowed.

class BetaCompactionConfig: type: "summarize"; instructions

Compact the whole conversation and return a signed compaction block, alone, that a later request sends back first in messages, in place of the messages it summarizes. There is no trigger and no pause flag: sending the parameter compacts, and nothing is sampled after the block.

The summarization prompt is the server's own unless instructions are given, which then replace it for this request; a value that is empty or only whitespace counts as absent.

type: Literal["summarize"]
instructions: Optional[str]

Replaces the server's default summarization prompt for this request. An empty or whitespace-only value counts as absent.

maxLength16384
class BetaCompactionContentBlockDelta: type: "compaction_delta"; content; encrypted_content
type: Literal["compaction_delta"]
defaultcompaction_delta
content: Optional[str]
encrypted_content: Optional[str]

Opaque metadata from prior compaction, to be round-tripped verbatim

class BetaCompactionIterationUsage: type: "compaction"; cache_creation; cache_creation_input_tokens; ... # 3 more

Token usage for a compaction iteration.

type: Literal["compaction"]

Usage for a compaction iteration

defaultcompaction
cache_creation: Optional[BetaCacheCreation]

Breakdown of cached tokens by TTL

ephemeral_1h_input_tokens: int

The number of input tokens used to create the 1 hour cache entry.

default0
minimum0
ephemeral_5m_input_tokens: int

The number of input tokens used to create the 5 minute cache entry.

default0
minimum0
cache_creation_input_tokens: int

The number of input tokens used to create the cache entry.

default0
minimum0
cache_read_input_tokens: int

The number of input tokens read from the cache.

default0
minimum0
input_tokens: int

The number of input tokens which were used.

minimum0
output_tokens: int

The number of output tokens which were used.

minimum0
class BetaComputerCursorPositionConfig: defer_loading; enabled

cursor_position's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerCursorPositionInput: ...

Get the current (x, y) pixel coordinate of the cursor.

class BetaComputerCursorPositionToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerDoubleClickConfig: defer_loading; enabled

double_click's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerDoubleClickInput: coordinate; text

Double-click the left mouse button at the specified (x, y) pixel coordinate, or the current cursor position if coordinate is omitted.

coordinate: Optional[List[int]]

(x, y): x pixels from the left edge, y pixels from the top edge.

minItems2
maxItems2
text: Optional[str]

Optional key combination to hold down during this action (e.g. "ctrl", "shift", "ctrl+shift").

class BetaComputerDoubleClickToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerHoldKeyConfig: defer_loading; enabled

hold_key's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerHoldKeyInput: duration; text

Hold down a key or key-combination for a specified duration. Uses the same key syntax as key.

duration: int

Duration to hold the key, in seconds.

maximum300
text: str

The key or key-combination to hold.

class BetaComputerHoldKeyToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerKeyConfig: defer_loading; enabled

key's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerKeyInput: text; repeat

Press a key or key-combination on the keyboard. Use "+" to combine modifiers with a key (e.g. "ctrl+s", "alt+Tab", "ctrl+shift+Escape"). Key names are case-insensitive; common names like "Return", "Tab", "Escape", "Up", "Down", "Left", "Right", "Home", "End", "Page_Up", "Page_Down", "Delete", "BackSpace" are supported.

text: str

The key or key-combination to press.

repeat: Optional[int]

Number of times to repeat the key press. Default is 1.

minimum1
maximum100
class BetaComputerKeyToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerLeftClickConfig: defer_loading; enabled

left_click's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerLeftClickDragConfig: defer_loading; enabled

left_click_drag's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerLeftClickDragInput: coordinate; start_coordinate; text

Click and drag the cursor from start_coordinate to coordinate.

coordinate: List[int]

(x, y): x pixels from the left edge, y pixels from the top edge.

minItems2
maxItems2
start_coordinate: List[int]

(x, y): x pixels from the left edge, y pixels from the top edge.

minItems2
maxItems2
text: Optional[str]

Optional key combination to hold down during this action (e.g. "ctrl", "shift", "ctrl+shift").

class BetaComputerLeftClickDragToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerLeftClickInput: coordinate; text

Click the left mouse button at the specified (x, y) pixel coordinate, or the current cursor position if coordinate is omitted.

coordinate: Optional[List[int]]

(x, y): x pixels from the left edge, y pixels from the top edge.

minItems2
maxItems2
text: Optional[str]

Optional key combination to hold down during this action (e.g. "ctrl", "shift", "ctrl+shift").

class BetaComputerLeftClickToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerLeftMouseDownConfig: defer_loading; enabled

left_mouse_down's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerLeftMouseDownInput: ...

Press and hold the left mouse button at the current cursor position.

class BetaComputerLeftMouseDownToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerLeftMouseUpConfig: defer_loading; enabled

left_mouse_up's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerLeftMouseUpInput: ...

Release the left mouse button.

class BetaComputerLeftMouseUpToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerMiddleClickConfig: defer_loading; enabled

middle_click's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerMiddleClickInput: coordinate; text

Click the middle mouse button at the specified (x, y) pixel coordinate, or the current cursor position if coordinate is omitted.

coordinate: Optional[List[int]]

(x, y): x pixels from the left edge, y pixels from the top edge.

minItems2
maxItems2
text: Optional[str]

Optional key combination to hold down during this action (e.g. "ctrl", "shift", "ctrl+shift").

class BetaComputerMiddleClickToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerMouseMoveConfig: defer_loading; enabled

mouse_move's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerMouseMoveInput: coordinate

Move the cursor to a specified (x, y) pixel coordinate. Use this ONLY to hover without clicking; otherwise use a click action directly.

coordinate: List[int]

(x, y): x pixels from the left edge, y pixels from the top edge.

minItems2
maxItems2
class BetaComputerMouseMoveToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerRightClickConfig: defer_loading; enabled

right_click's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerRightClickInput: coordinate; text

Click the right mouse button at the specified (x, y) pixel coordinate, or the current cursor position if coordinate is omitted.

coordinate: Optional[List[int]]

(x, y): x pixels from the left edge, y pixels from the top edge.

minItems2
maxItems2
text: Optional[str]

Optional key combination to hold down during this action (e.g. "ctrl", "shift", "ctrl+shift").

class BetaComputerRightClickToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerScreenshotConfig: defer_loading; enabled

screenshot's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerScreenshotInput: ...

Take a screenshot of the screen.

class BetaComputerScreenshotToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerScrollConfig: defer_loading; enabled

scroll's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

type BetaComputerScrollDirection = Literal["up", "down", "left", "right"]
One of the following:
"up"
"down"
"left"
"right"
class BetaComputerScrollInput: scroll_amount; scroll_direction; coordinate; text

Scroll the screen at the specified (x, y) pixel coordinate, or the current cursor position if coordinate is omitted. Do NOT use PageUp/PageDown to scroll.

scroll_amount: int

Number of 'clicks' of the scroll wheel.

scroll_direction: BetaComputerScrollDirection
One of the following:
"up"
"down"
"left"
"right"
coordinate: Optional[List[int]]

(x, y): x pixels from the left edge, y pixels from the top edge.

minItems2
maxItems2
text: Optional[str]

Optional key combination to hold down during this action (e.g. "ctrl", "shift", "ctrl+shift").

class BetaComputerScrollToolUseBlock: type: "tool_use"; id; input; ... # 3 more
type BetaComputerToolUseBlock = ...
One of the following:
class BetaComputerToolset20260801: type: "computer_toolset_20260801"; cache_control; configs

The computer toolset: a single tools[] entry (carrying no name) that declares the computer tool family. The model is served the family's tool with any members disabled via configs removed from its schema. Every member is enabled by default, zoom included. The single-tool options display_number and enable_zoom are not fields of a toolset entry — it carries only type, configs, and cache_control; zoom is controlled via configs.zoom.enabled.

type: Literal["computer_toolset_20260801"]
cache_control: Optional[BetaCacheControlEphemeral]

Create a cache control breakpoint at this content block.

type: Literal["ephemeral"]
ttl: Optional[Literal["5m", "1h"]]

The time-to-live for the cache control breakpoint.

This may be one the following values:

  • 5m: 5 minutes
  • 1h: 1 hour

Defaults to 5m. See prompt caching pricing for details.

One of the following:
"5m"
"1h"
configs: Optional[BetaComputerToolsetConfigs]

Sparse per-member overrides, keyed by member name. Absent, null, and {} are equivalent; a member's defaults apply wherever its key is absent.

class BetaComputerToolsetConfigs: type; cursor_position; double_click; ... # 14 more

Per-member configuration for computer_toolset_20260801: one optional field per member tool, keyed by the member name — the same name the member's tool_use blocks carry. Every member is an accepted key, and a member's defaults apply wherever its key is absent. Unknown keys are rejected: the field set is this toolset version's complete member set.

class BetaComputerTripleClickConfig: defer_loading; enabled

triple_click's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerTripleClickInput: coordinate; text

Triple-click the left mouse button at the specified (x, y) pixel coordinate, or the current cursor position if coordinate is omitted.

coordinate: Optional[List[int]]

(x, y): x pixels from the left edge, y pixels from the top edge.

minItems2
maxItems2
text: Optional[str]

Optional key combination to hold down during this action (e.g. "ctrl", "shift", "ctrl+shift").

class BetaComputerTripleClickToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerTypeConfig: defer_loading; enabled

type's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerTypeInput: text

Type a string of text on the keyboard.

text: str

The text to type.

class BetaComputerTypeToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerWaitConfig: defer_loading; enabled

wait's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerWaitInput: duration

Wait for a specified duration.

duration: int

Duration to wait, in seconds.

maximum300
class BetaComputerWaitToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaComputerZoomConfig: defer_loading; enabled

zoom's config overrides.

defer_loading: Optional[bool]

Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.

enabled: Optional[bool]

Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.

class BetaComputerZoomInput: region

Take a screenshot of a rectangular region. Region coordinates are in the full-screenshot space (not physical display pixels). The crop is scaled up to fill the image budget so fine details become legible.

region: List[int]

(x0, y0, x1, y1): The region to capture.

minItems4
maxItems4
class BetaComputerZoomToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaContainer: id; expires_at; skills

Information about the container used in the request (for the code execution tool)

id: str

Identifier for the container used in this request

expires_at: datetime

The time at which the container will expire.

formatdate-time
skills: Optional[List[BetaContainerSkill]]

Skills loaded in the container

type: Literal["anthropic", "custom"]

Type of skill - either 'anthropic' (built-in) or 'custom' (user-defined)

One of the following:
"anthropic"
"custom"
skill_id: str

Skill ID

minLength1
maxLength64
version: str

The resolved version: a skill version ID for custom skills.

minLength1
maxLength64
class BetaContainerParams: id; skills

Container parameters with skills to be loaded.

id: Optional[str]

Container id

skills: Optional[List[BetaSkillParams]]

List of skills to load in the container

maxItems20
type: Literal["anthropic", "custom"]

Type of skill - either 'anthropic' (built-in) or 'custom' (user-defined)

One of the following:
"anthropic"
"custom"
skill_id: str

Skill ID

minLength1
maxLength64
version: Optional[str]

Skill version or 'latest' for most recent version

minLength1
maxLength64
class BetaContainerSkill: type; skill_id; version

A skill that was loaded in a container (response model).

type: Literal["anthropic", "custom"]

Type of skill - either 'anthropic' (built-in) or 'custom' (user-defined)

One of the following:
"anthropic"
"custom"
skill_id: str

Skill ID

minLength1
maxLength64
version: str

The resolved version: a skill version ID for custom skills.

minLength1
maxLength64
class BetaContainerUploadBlock: type: "container_upload"; file_id

Response model for a file uploaded to the container.

type: Literal["container_upload"]
defaultcontainer_upload
file_id: str
class BetaContainerUploadBlockParam: type: "container_upload"; file_id; cache_control

A content block that represents a file to be uploaded to the container Files uploaded via this block will be available in the container's input directory.

type: Literal["container_upload"]
file_id: str
cache_control: Optional[BetaCacheControlEphemeral]

Create a cache control breakpoint at this content block.

type: Literal["ephemeral"]
ttl: Optional[Literal["5m", "1h"]]

The time-to-live for the cache control breakpoint.

This may be one the following values:

  • 5m: 5 minutes
  • 1h: 1 hour

Defaults to 5m. See prompt caching pricing for details.

One of the following:
"5m"
"1h"
type BetaContentBlock = ...
One of the following:
type BetaContentBlockParam = ...
One of the following:
class BetaContentBlockSource: type: "content"; content
type: Literal["content"]
content: Union[str, List[BetaContentBlockSourceContent]]
One of the following:
str
One of the following:
class BetaTextBlockParam: type: "text"; text; cache_control; citations
class BetaImageBlockParam: type: "image"; source; cache_control; transformations
type BetaContentBlockSourceContent = ...
One of the following:
class BetaTextBlockParam: type: "text"; text; cache_control; citations
class BetaImageBlockParam: type: "image"; source; cache_control; transformations
class BetaContextManagementConfig: edits
class BetaContextManagementResponse: applied_edits
class BetaCountTokensContextManagementResponse: original_input_tokens
original_input_tokens: int

The original token count before context management was applied

class BetaDiagnostics: cache_miss_reason

Request-level diagnostics: why the prompt cache could not fully reuse the prefix of the request named by diagnostics.previous_message_id.

cache_miss_reason: Optional[BetaCacheMissReason]

Explains why the prompt cache could not fully reuse the prefix from the request identified by diagnostics.previous_message_id. null means diagnosis is still pending — the response was serialized before the background comparison completed.

One of the following:
class BetaDiagnosticsParam: previous_message_id

Request-level diagnostics. Currently carries the previous response id for prompt-cache divergence reporting.

previous_message_id: Optional[str]

The id (msg_...) from this client's previous /v1/messages response. The server compares that request's prompt fingerprint against this one and returns diagnostics.cache_miss_reason when the prompt-cache prefix could not be reused. Pass null on the first turn to opt in without a prior message to compare.

maxLength256
class BetaDirectCaller: type: "direct"

Tool invocation directly from the model.

type: Literal["direct"]
class BetaDocumentBlock: type: "document"; citations; source; title
class BetaEncryptedCodeExecutionResultBlock: type: "encrypted_code_execution_result"; content; encrypted_stdout; ... # 2 more

Code execution result with encrypted stdout for PFC + web_search results.

type: Literal["encrypted_code_execution_result"]
defaultencrypted_code_execution_result
type: Literal["code_execution_output"]
defaultcode_execution_output
file_id: str
encrypted_stdout: str
return_code: int
stderr: str
class BetaEncryptedCodeExecutionResultBlockParam: type: "encrypted_code_execution_result"; content; encrypted_stdout; ... # 2 more

Code execution result with encrypted stdout for PFC + web_search results.

type: Literal["encrypted_code_execution_result"]
type: Literal["code_execution_output"]
file_id: str
encrypted_stdout: str
return_code: int
stderr: str
class BetaFallbackBlock: type: "fallback"; from_; to; trigger

Marks the point in content where one model's output gives way to the next.

One block appears per hop where a preceding model actually ran this turn and declined. A turn where no preceding model ran and declined has no such boundary and carries no block — the signal for whether a fallback model served the response is the presence of a fallback_message entry in usage.iterations, not this block.

The block is treated like a server-tool content block for streaming: it arrives via the standard content_block_start / content_block_stop pair and carries no deltas.

class BetaFallbackBlockParam: type: "fallback"; from_; to; trigger

A fallback block echoed back from a prior response.

Accepted in messages[].content and not rendered into the prompt; not validated against the request's fallbacks chain or top-level model.

Echo the assistant turn back verbatim, including this block in its original position. The block marks the boundary between content produced before and after a fallback hop, and the server relies on that boundary to validate the turn: when thinking runs flank the boundary, omitting the block merges them into one span the server cannot validate (the request is rejected), and moving it into the middle of a single run is likewise rejected; between non-thinking blocks the block's placement has no validation effect.

type: Literal["fallback"]

Identifies one hop of a fallback transition.

Identifies one hop of a fallback transition.

trigger: Optional[object]

The response block's trigger, echoed verbatim. Accepted and ignored by the server; any object or null is allowed.

class BetaFallbackCreditNotApplied: type: "not_applied"; reason; remove_to_redeem

No reprice was applied; reason says why.

class BetaFallbackCreditRedeemed: type: "redeemed"

The reprice was applied: the retry is billed as if the conversation had been on the retry model all along.

type: Literal["redeemed"]
defaultredeemed
class BetaFallbackCreditTokenParam: token; mode

Object form of fallback_credit_token: the token plus a redemption mode.

Requires anthropic-beta: fallback-credit-2026-07-01; without that header the field accepts the bare string only. The bare string and the mode-less object are equivalent (both select strict), so wrapping an existing token changes nothing by itself.

token: str

The opaque fallback_credit_token from a prior refusal's stop_details — the same string the bare-string form carries.

minLength1
maxLength2048
mode: Optional[Literal["strict", "best_effort"]]

How a failing token affects the retry. strict (the default, and the bare-string behavior): a failing redemption is a 400 and the retry is not served. best_effort: the retry is served either way — a token-layer failure no longer rejects the request; the retry proceeds at normal price and the outcome is reported on the response's usage.fallback_credit. Two failures stay hard in both modes: a malformed token, and combining fallback_credit_token with fallbacks.

One of the following:
"strict"
"best_effort"
class BetaFallbackCreditUsage: status

Outcome of the fallback_credit_token presented on this request.

status: Status

Whether the fallback-credit reprice was applied to this response's billing.

A union discriminated on type. redeemed: the retry is billed as if the conversation had been on the retry model all along — including when the resulting shift is zero because there was nothing to move. not_applied: no reprice was applied; the arm's reason says why.

One of the following:
class BetaFallbackCreditRedeemed: type: "redeemed"

The reprice was applied: the retry is billed as if the conversation had been on the retry model all along.

type: Literal["redeemed"]
defaultredeemed
class BetaFallbackCreditNotApplied: type: "not_applied"; reason; remove_to_redeem

No reprice was applied; reason says why.

class BetaFallbackInfo: model

Identifies one hop of a fallback transition.

class BetaFallbackInfoParam: model

Identifies one hop of a fallback transition.

class BetaFallbackMessageIterationUsage: type: "fallback_message"; cache_creation; cache_creation_input_tokens; ... # 4 more

Token usage for the fallback-model attempt of a server-side fallback request.

The terminal entry of a fallback-served turn: when a fallback hop's output is the returned message, the entry for the iteration that completed it carries this type in place of message. A declined hop and the serving hop's earlier tool-loop iterations produce message entries. Whether a fallback model served the response is signalled by the presence of this entry in usage.iterations.

class BetaFallbackParam: model; max_tokens; output_config; ... # 2 more

One entry in the fallbacks chain on a /v1/messages request.

model is required. The override fields (max_tokens, thinking, output_config, and speed) set the corresponding parameter for this attempt only and are validated as if the request were made to model. Any other key is rejected at parse time.

class BetaFallbackRefusalTrigger: type: "refusal"; category

The from model declined for policy reasons.

type: Literal["refusal"]
defaultrefusal
category: Optional[Literal["cyber", "bio", "frontier_llm", 2 more]]

The policy category that triggered the from model's refusal at this hop. null when the refusal doesn't map to a named category. Same vocabulary as stop_details.category.

One of the following:
"cyber"

The request could enable cyber harm, such as malware or exploit development. Benign cybersecurity work can also trigger this category.

"bio"

The request could enable biological harm, such as dangerous lab methods. Beneficial life sciences work can also trigger this category.

"frontier_llm"

The request could assist the development of competing AI models, which is restricted under Anthropic's commercial terms. Benign machine learning work can also trigger this category.

"reasoning_extraction"

The request asks the model to reproduce its internal reasoning in the response text. To get reasoning in a structured form instead, use adaptive thinking.

"general_harms"

The request could be related to an area that was determined as harmful. Benign work might sometimes trigger this category.

type BetaFallbacksParam = Union[List[BetaFallbackParam], Literal["default"], null]

Opt-in server-side retry on one or more substitute models when the requested model declines for policy reasons. Tried in order: if the first entry also declines, the second is tried, and so on. Some models don't support fallbacks; on those models, a list of fallback models returns a 400 error. See Server-side fallback. The string "default" requests the requested model's server-defined default fallback configuration. On a model that doesn't support fallbacks, the request runs on the requested model alone, so a declined request stays declined.

One of the following:
class BetaFileDocumentSource: type: "file"; file_id
type: Literal["file"]
file_id: str
class BetaFileImageSource: type: "file"; file_id
type: Literal["file"]
file_id: str
class BetaImageBlockParam: type: "image"; source; cache_control; transformations
class BetaImageTransformationsParam: oversized_image

Configures the transformations the server applies to this image before the model observes it. Each key names a condition the server transforms images for; its value selects the transformation applied. Omitted keys keep their default behavior, and an empty object is equivalent to omitting the field.

oversized_image: Optional[Literal["downsize", "error"]]

What the server does when this image exceeds the model's maximum image size. "downsize" (the default) scales the image down to fit, which changes the dimensions the model observes without telling you. "error" instead rejects the request with a 400 error naming the image's dimensions and the largest dimensions that fit, so you can scale the image deliberately — your image is never silently scaled down.

One of the following:
"downsize"
"error"
class BetaInputJSONDelta: type: "input_json_delta"; partial_json
type: Literal["input_json_delta"]
defaultinput_json_delta
partial_json: str
class BetaInputTokensClearAtLeast: type: "input_tokens"; value
type: Literal["input_tokens"]
value: int
minimum0
class BetaInputTokensTrigger: type: "input_tokens"; value
type: Literal["input_tokens"]
value: int
minimum1
type BetaInputTransformation = ...

One entry of input_transformations: either a change the API made to the request's input before showing it to the model, or a block that failed a binding check and was still shown to the model unchanged. The type field says which.

One of the following:
type BetaIterationsUsage = Optional[List[BetaIterationsUsageItem]]

Per-iteration token usage breakdown.

Each entry represents one sampling iteration, with its own input/output token counts and cache statistics, discriminated by type. For message entries (model sampling iterations, such as the turns of a server-side tool use loop), this allows you to:

  • Calculate the context window size from the last message entry
  • Understand token accumulation across server-side tool use loops

A compaction entry reports the token usage of the compaction operation itself — the server-side request that summarizes the context being closed — NOT the size of the context that was compacted away, and its token counts can be much smaller than that closed context (for example, a compaction that closes a ~200k-token context can report only a few thousand tokens). Do not derive the context window size from a compaction entry, even when it is the last entry. A compaction entry's tokens are not included in the top-level usage fields. When an input-token trigger is in effect (the default — 150,000 tokens unless configured otherwise), each compaction entry closes a context that had reached at least that threshold, though the context can exceed it by the final iteration's output and tool results.

One of the following:
class BetaJSONOutputFormat: type: "json_schema"; schema
type: Literal["json_schema"]
schema: Dict[str, object]

The JSON schema of the format

class BetaMCPTool: input_schema; name; description

A tool as an MCP server lists it: its name on that server, its description, and its input schema.

input_schema: Dict[str, object]
name: str
description: Optional[str]
class BetaMCPToolConfig: defer_loading; enabled

Configuration for a specific tool in an MCP toolset.

defer_loading: Optional[bool]
enabled: Optional[bool]
class BetaMCPToolDefaultConfig: defer_loading; enabled

Default configuration for tools in an MCP toolset.

defer_loading: Optional[bool]
enabled: Optional[bool]
class BetaMCPToolListingBlock: type: "mcp_tool_listing"; mcp_server_name; tools

The tool listing the server fetched from an MCP server while producing this response. Send the assistant message back unchanged, this block included, so later requests use this listing instead of asking the MCP server again.

type: Literal["mcp_tool_listing"]
defaultmcp_tool_listing
mcp_server_name: str
tools: List[BetaMCPTool]
input_schema: Dict[str, object]
name: str
description: Optional[str]
class BetaMCPToolListingBlockParam: type: "mcp_tool_listing"; mcp_server_name; tools

The tool listing an MCP server returned while an earlier response was produced, as that response carried it. Send the assistant message back unchanged, this block included, and the server uses this listing for the matching mcp_toolset instead of asking the MCP server again.

type: Literal["mcp_tool_listing"]
mcp_server_name: str

The name of the MCP server this listing came from, as mcp_servers declares it.

minLength1
maxLength255
tools: List[BetaMCPToolParam]

The server's tools, exactly as the response listed them.

input_schema: Dict[str, object]

The tool's input schema as the MCP server lists it, verbatim.

name: str

The tool's name as the MCP server lists it (not prefixed with the server name).

minLength1
description: Optional[str]

The tool's description as the MCP server lists it.

class BetaMCPToolParam: input_schema; name; description

A tool as an MCP server lists it: its name on that server, its description, and its input schema.

input_schema: Dict[str, object]

The tool's input schema as the MCP server lists it, verbatim.

name: str

The tool's name as the MCP server lists it (not prefixed with the server name).

minLength1
description: Optional[str]

The tool's description as the MCP server lists it.

class BetaMCPToolResultBlock: type: "mcp_tool_result"; content; is_error; tool_use_id
class BetaMCPToolUseBlock: type: "mcp_tool_use"; id; input; ... # 2 more
type: Literal["mcp_tool_use"]
defaultmcp_tool_use
id: str
pattern^[a-zA-Z0-9_-]+$
input: Dict[str, object]
name: str

The name of the MCP tool

server_name: str

The name of the MCP server

class BetaMCPToolUseBlockParam: type: "mcp_tool_use"; id; input; ... # 3 more
class BetaMCPToolset: type: "mcp_toolset"; mcp_server_name; cache_control; ... # 3 more

Configuration for a group of tools from an MCP server.

Allows configuring enabled status and defer_loading for all tools from an MCP server, with optional per-tool overrides.

class BetaMemoryTool20250818: type: "memory_20250818"; name; allowed_callers; ... # 4 more
type BetaMemoryTool20250818Command = ...
One of the following:
class BetaMemoryTool20250818CreateCommand: command; file_text; path
command: Literal["create"]

Command type identifier

defaultcreate
file_text: str

Content to write to the file

path: str

Path where the file should be created

class BetaMemoryTool20250818DeleteCommand: command; path
command: Literal["delete"]

Command type identifier

defaultdelete
path: str

Path to the file or directory to delete

class BetaMemoryTool20250818InsertCommand: command; insert_line; insert_text; path
command: Literal["insert"]

Command type identifier

defaultinsert
insert_line: int

Line number where text should be inserted

minimum1
insert_text: str

Text to insert at the specified line

path: str

Path to the file where text should be inserted

class BetaMemoryTool20250818RenameCommand: command; new_path; old_path
command: Literal["rename"]

Command type identifier

defaultrename
new_path: str

New path for the file or directory

old_path: str

Current path of the file or directory

class BetaMemoryTool20250818StrReplaceCommand: command; new_str; old_str; path
command: Literal["str_replace"]

Command type identifier

defaultstr_replace
new_str: str

Text to replace with

old_str: str

Text to search for and replace

path: str

Path to the file where text should be replaced

class BetaMemoryTool20250818ViewCommand: command; path; view_range
command: Literal["view"]

Command type identifier

defaultview
path: str

Path to directory or file to view

view_range: Optional[List[int]]

Optional line range for viewing specific lines

minItems2
maxItems2
class BetaMessage: type: "message"; id; container; ... # 10 more
class BetaMessageDeltaUsage: cache_creation_input_tokens; cache_read_input_tokens; fallback_credit; ... # 5 more
class BetaMessageIterationUsage: type: "message"; cache_creation; cache_creation_input_tokens; ... # 4 more

Token usage for a sampling iteration.

type: Literal["message"]

Usage for a sampling iteration

defaultmessage
cache_creation: Optional[BetaCacheCreation]

Breakdown of cached tokens by TTL

ephemeral_1h_input_tokens: int

The number of input tokens used to create the 1 hour cache entry.

default0
minimum0
ephemeral_5m_input_tokens: int

The number of input tokens used to create the 5 minute cache entry.

default0
minimum0
cache_creation_input_tokens: int

The number of input tokens used to create the cache entry.

default0
minimum0
cache_read_input_tokens: int

The number of input tokens read from the cache.

default0
minimum0
input_tokens: int

The number of input tokens which were used.

minimum0
model: Optional[Model]

The model that will complete your prompt.

See models for additional details and options.

One of the following:
output_tokens: int

The number of output tokens which were used.

minimum0
class BetaMessageParam: content; role; clear_at; output_config
class BetaMessageTokensCount: context_management; input_tokens
context_management: Optional[BetaCountTokensContextManagementResponse]

Information about context management applied to the message.

original_input_tokens: int

The original token count before context management was applied

input_tokens: int

The total number of tokens across the provided list of messages, system prompt, and tools.

class BetaMetadata: user_id
user_id: Optional[str]

An external identifier for the user who is associated with the request.

This should be a uuid, hash value, or other opaque identifier. Anthropic may use this id to help detect abuse. Do not include any identifying information such as name, email address, or phone number.

maxLength512
class BetaOutputConfig: effort; format; task_budget
class BetaOutputTokensDetails: thinking_tokens
thinking_tokens: int

Number of output tokens the model generated as internal reasoning, including the thinking-block delimiter tokens.

Reflects the raw reasoning the model produced, not the (possibly shorter) summarized thinking text returned in the response body. Computed by re-tokenizing the raw reasoning text, so it may differ from the model's exact generation count by a small number of tokens. Always ≤ output_tokens; output_tokens - thinking_tokens approximates the non-reasoning output.

default0
minimum0
class BetaPlainTextSource: type: "text"; data; media_type
type: Literal["text"]
data: str
media_type: Literal["text/plain"]
type BetaRawContentBlockDelta = ...
One of the following:
class BetaRawContentBlockDeltaEvent: type: "content_block_delta"; delta; index
type: Literal["content_block_delta"]
defaultcontent_block_delta
One of the following:
index: int
class BetaRawContentBlockStartEvent: type: "content_block_start"; content_block; index
class BetaRawContentBlockStopEvent: type: "content_block_stop"; index
type: Literal["content_block_stop"]
defaultcontent_block_stop
index: int
class BetaRawMessageDeltaEvent: type: "message_delta"; context_management; delta; ... # 2 more
class BetaRawMessageStartEvent: type: "message_start"; message
type: Literal["message_start"]
defaultmessage_start
message: BetaMessage
class BetaRawMessageStopEvent: type: "message_stop"
type: Literal["message_stop"]
defaultmessage_stop
type BetaRawMessageStreamEvent = ...
One of the following:
class BetaRedactedThinkingBlock: type: "redacted_thinking"; data
type: Literal["redacted_thinking"]
defaultredacted_thinking
data: str

The contents of this redacted thinking block, returned when portions of the model's thinking were safety-redacted. This field is opaque and encrypted, with no readable content.

Pass redacted_thinking blocks back to the API unchanged when continuing a multi-turn conversation.

See extended thinking for details.

class BetaRedactedThinkingBlockParam: type: "redacted_thinking"; data
type: Literal["redacted_thinking"]
data: str

The data value of this redacted thinking block, exactly as returned by the API in a previous response. Opaque and encrypted; pass it back unchanged.

class BetaRefusalStopDetails: type: "refusal"; category; explanation; ... # 3 more

Structured information about a refusal.

class BetaRequestDocumentBlock: type: "document"; source; cache_control; ... # 3 more
class BetaRequestMCPServerToolConfiguration: allowed_tools; enabled
allowed_tools: Optional[List[str]]
enabled: Optional[bool]
class BetaRequestMCPServerURLDefinition: type: "url"; name; url; ... # 2 more
type: Literal["url"]
name: str
url: str
authorization_token: Optional[str]
tool_configuration: Optional[BetaRequestMCPServerToolConfiguration]
allowed_tools: Optional[List[str]]
enabled: Optional[bool]
class BetaRequestMCPToolResultBlockParam: type: "mcp_tool_result"; tool_use_id; cache_control; ... # 2 more
class BetaRequestToolAdditionBlock: type: "tool_addition"; tool; cache_control

Mid-conversation directive to make a tool available.

tool is a reference to a tool (or MCP toolset) declared in the request's tools. Under the inline-tools-2026-09-15 beta it may instead be a reference to a tool defined earlier in messages, or a tool_definition object that carries an inline tool definition in definition (the same object a tools entry holds). An mcp_toolset definition also requires the mcp-client-2026-09-15 beta. The tool is offered to the model from this point in the conversation onward.

class BetaRequestToolRemovalBlock: type: "tool_removal"; tool; cache_control

Mid-conversation directive to withdraw a tool.

tool references a tool (or MCP toolset) by name: one declared in the request's tools or defined earlier in messages. It is no longer offered to the model from this point in the conversation onward.

class BetaResponseTool: type; input_schema; name; ... # 6 more

A custom tool definition, as sent.

class BetaResponseToolAdditionBlock: type: "tool_addition"; tool

An entry of a compaction block's tool_changes: a tool the compacted range made available, as a reference to a tools entry or MCP toolset, or as the tool definition in effect at the end of the range, by value. Send it back unchanged.

class BetaResponseToolChangeMCPToolReference: type: "mcp_tool_reference"; name; server_name

Reference to a single MCP tool, by its server and its name on that server, as a compaction block's tool_changes entry reports it. Send it back unchanged with the block.

type: Literal["mcp_tool_reference"]
defaultmcp_tool_reference
name: str
server_name: str
class BetaResponseToolChangeMCPToolsetReference: type: "mcp_toolset_reference"; server_name

Reference to every tool in the named MCP server's toolset, as a compaction block's tool_changes entry reports it. Send it back unchanged with the block.

type: Literal["mcp_toolset_reference"]
defaultmcp_toolset_reference
server_name: str
class BetaResponseToolChangeToolReference: type: "tool_reference"; name

Reference to a single tool, by the name the model uses to call it, as a compaction block's tool_changes entry reports it: a tool declared in tools or defined by an earlier tool_addition block. Send it back unchanged with the block.

type: Literal["tool_reference"]
defaulttool_reference
name: str
class BetaResponseToolInputSchema: type: "object"; properties; required

JSON schema for this tool's input.

This defines the shape of the input that your tool accepts and that the model will produce.

type: Literal["object"]
properties: Optional[Dict[str, object]]
required: Optional[List[str]]
class BetaResponseToolRemovalBlock: type: "tool_removal"; tool

An entry of a compaction block's tool_changes: a tool of the request's tools (or an MCP tool or toolset) that the compacted range withdrew. Send it back unchanged.

type BetaResponseToolUnion = ...
One of the following:
class BetaSearchResultBlockParam: type: "search_result"; content; source; ... # 3 more
class BetaServerToolCaller: type: "code_execution_20250825"; tool_id

Tool invocation generated by a server-side tool.

type: Literal["code_execution_20250825"]
tool_id: str
pattern^srvtoolu_[a-zA-Z0-9_]+$
class BetaServerToolCaller20260120: type: "code_execution_20260120"; tool_id
type: Literal["code_execution_20260120"]
tool_id: str
pattern^srvtoolu_[a-zA-Z0-9_]+$
class BetaServerToolUsage: web_fetch_requests; web_search_requests
web_fetch_requests: int

The number of web fetch tool requests.

default0
minimum0
web_search_requests: int

The number of web search tool requests.

default0
minimum0
class BetaServerToolUseBlock: type: "server_tool_use"; id; input; ... # 2 more
class BetaServerToolUseBlockParam: type: "server_tool_use"; id; input; ... # 3 more
class BetaSignatureDelta: type: "signature_delta"; signature
type: Literal["signature_delta"]
defaultsignature_delta
signature: str

The signature for this thinking block: an opaque value used to verify that the block was generated by Claude when it is passed back to the API. Delivered in a signature_delta event just before the block's content_block_stop event.

class BetaSkillParams: type; skill_id; version

Specification for a skill to be loaded in a container (request model).

type: Literal["anthropic", "custom"]

Type of skill - either 'anthropic' (built-in) or 'custom' (user-defined)

One of the following:
"anthropic"
"custom"
skill_id: str

Skill ID

minLength1
maxLength64
version: Optional[str]

Skill version or 'latest' for most recent version

minLength1
maxLength64
type BetaStopReason = Literal["end_turn", "max_tokens", "stop_sequence", 5 more]
One of the following:
"end_turn"
"max_tokens"
"stop_sequence"
"tool_use"
"pause_turn"
"compaction"
"refusal"
"model_context_window_exceeded"
class BetaSummarizeCompaction: type: "summarize"; instructions

Compact the whole conversation and return a signed compaction block, alone, that a later request sends back first in messages, in place of the messages it summarizes. There is no trigger and no pause flag: sending the parameter compacts, and nothing is sampled after the block.

The summarization prompt is the server's own unless instructions are given, which then replace it for this request; a value that is empty or only whitespace counts as absent.

type: Literal["summarize"]
instructions: Optional[str]

Replaces the server's default summarization prompt for this request. An empty or whitespace-only value counts as absent.

maxLength16384
class BetaSystemMessageOutputConfig: effort

Per-message output configuration on a role:"system" input message.

Fields here apply per-turn; format remains top-level only. An empty {} is accepted on a message that carries content; a message with neither content nor output_config fields is rejected.

effort: Optional[Literal["low", "medium", "high", 2 more]]

How much effort the model should put into its response. Higher effort levels may result in more thorough analysis but take longer.

Valid values are low, medium, high, xhigh, or max.

One of the following:
"low"
"medium"
"high"
"xhigh"
"max"
class BetaTextBlock: type: "text"; citations; text
class BetaTextBlockParam: type: "text"; text; cache_control; citations
type BetaTextCitation = ...
One of the following:
type BetaTextCitationParam = ...
One of the following:
class BetaTextDelta: type: "text_delta"; text
type: Literal["text_delta"]
defaulttext_delta
text: str
class BetaTextEditorCodeExecutionCreateResultBlock: type: "text_editor_code_execution_create_result"; is_file_update
type: Literal["text_editor_code_execution_create_result"]
defaulttext_editor_code_execution_create_result
is_file_update: bool
class BetaTextEditorCodeExecutionCreateResultBlockParam: type: "text_editor_code_execution_create_result"; is_file_update
type: Literal["text_editor_code_execution_create_result"]
is_file_update: bool
class BetaTextEditorCodeExecutionStrReplaceResultBlock: type: "text_editor_code_execution_str_replace_result"; lines; new_lines; ... # 3 more
type: Literal["text_editor_code_execution_str_replace_result"]
defaulttext_editor_code_execution_str_replace_result
lines: Optional[List[str]]
new_lines: Optional[int]
new_start: Optional[int]
old_lines: Optional[int]
old_start: Optional[int]
class BetaTextEditorCodeExecutionStrReplaceResultBlockParam: type: "text_editor_code_execution_str_replace_result"; lines; new_lines; ... # 3 more
type: Literal["text_editor_code_execution_str_replace_result"]
lines: Optional[List[str]]
new_lines: Optional[int]
new_start: Optional[int]
old_lines: Optional[int]
old_start: Optional[int]
class BetaTextEditorCodeExecutionToolResultBlock: type: "text_editor_code_execution_tool_result"; content; tool_use_id
class BetaTextEditorCodeExecutionToolResultBlockParam: type: "text_editor_code_execution_tool_result"; content; tool_use_id; cache_control
class BetaTextEditorCodeExecutionToolResultError: type: "text_editor_code_execution_tool_result_error"; error_code; error_message
type: Literal["text_editor_code_execution_tool_result_error"]
defaulttext_editor_code_execution_tool_result_error
error_code: Literal["invalid_tool_input", "unavailable", "too_many_requests", 2 more]
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
"file_not_found"
error_message: Optional[str]
class BetaTextEditorCodeExecutionToolResultErrorParam: type: "text_editor_code_execution_tool_result_error"; error_code; error_message
type: Literal["text_editor_code_execution_tool_result_error"]
error_code: Literal["invalid_tool_input", "unavailable", "too_many_requests", 2 more]
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
"file_not_found"
error_message: Optional[str]
class BetaTextEditorCodeExecutionViewResultBlock: type: "text_editor_code_execution_view_result"; content; file_type; ... # 3 more
type: Literal["text_editor_code_execution_view_result"]
defaulttext_editor_code_execution_view_result
content: str
file_type: Literal["text", "image", "pdf"]
One of the following:
"text"
"image"
"pdf"
num_lines: Optional[int]
start_line: Optional[int]
total_lines: Optional[int]
class BetaTextEditorCodeExecutionViewResultBlockParam: type: "text_editor_code_execution_view_result"; content; file_type; ... # 3 more
type: Literal["text_editor_code_execution_view_result"]
content: str
file_type: Literal["text", "image", "pdf"]
One of the following:
"text"
"image"
"pdf"
num_lines: Optional[int]
start_line: Optional[int]
total_lines: Optional[int]
class BetaThinkingBlock: type: "thinking"; signature; thinking
type: Literal["thinking"]
defaultthinking
signature: str

A value used to verify that this thinking block was generated by Claude when it is passed back to the API.

This is an opaque field and should not be interpreted or parsed. When passing thinking blocks back to the API (required when using tools with extended thinking), pass them back exactly as received, with this field intact.

See extended thinking for details.

thinking: str

The text of Claude's thinking process for this block.

class BetaThinkingBlockBinding: prefix_mismatch_behavior

Controls for block binding: what happens when a thinking block this request sends back fails the conversation check. Every field is optional; an empty object means every default.

prefix_mismatch_behavior: Optional[BetaThinkingPrefixMismatchBehavior]

"error" (default) | "drop_block". What happens when a thinking block in messages fails the conversation check (it was created in a different conversation, or the messages before it have changed since). "error" fails the request with a 400 error. "drop_block" removes the failing blocks and the request proceeds; each removal is reported in input_transformations.

One of the following:
"error"
"drop_block"
class BetaThinkingBlockParam: type: "thinking"; signature; thinking
type: Literal["thinking"]
signature: str

The signature value of this thinking block, exactly as returned by the API in a previous response. Used to verify that the block was generated by Claude.

Thinking blocks must be passed back unmodified and in their original order; a modified block results in a 400 invalid_request_error.

thinking: str

The thinking text of this block as returned by the API.

class BetaThinkingConfigAdaptive: type: "adaptive"; block_binding; display
type: Literal["adaptive"]
block_binding: Optional[BetaThinkingBlockBinding]

Controls for block binding: what happens when a thinking block this request sends back fails the conversation check. null, absent or an empty object means every default.

prefix_mismatch_behavior: Optional[BetaThinkingPrefixMismatchBehavior]

"error" (default) | "drop_block". What happens when a thinking block in messages fails the conversation check (it was created in a different conversation, or the messages before it have changed since). "error" fails the request with a 400 error. "drop_block" removes the failing blocks and the request proceeds; each removal is reported in input_transformations.

One of the following:
"error"
"drop_block"
display: Optional[Literal["summarized", "omitted", "updates"]]

Controls how thinking content appears in the response. When set to summarized, thinking is returned normally. When set to omitted, thinking content is redacted but a signature is returned for multi-turn continuity. The default depends on the model; see Controlling thinking display.

One of the following:
"summarized"
"omitted"
"updates"
class BetaThinkingConfigBetweenTools: type: "between_tools"
type: Literal["between_tools"]
class BetaThinkingConfigDisabled: type: "disabled"
type: Literal["disabled"]
class BetaThinkingConfigEnabled: type: "enabled"; budget_tokens; block_binding; display
type BetaThinkingConfigParam = ...

Configuration for Claude's thinking.

With {"type": "adaptive"}, Claude decides when and how much to think. With {"type": "enabled"} (manual extended thinking), you set a budget_tokens of at least 1,024. Thinking tokens count toward your max_tokens limit.

Which type values are accepted, and what happens when you omit thinking, depend on the model. See thinking for each model's behavior.

One of the following:
class BetaThinkingDelta: type: "thinking_delta"; estimated_tokens; thinking
type: Literal["thinking_delta"]
defaultthinking_delta
estimated_tokens: Optional[int]

Per-frame increment of a coarse, running estimate of the tokens this thinking block has produced so far. Present whenever the thinking-token-count-2026-05-13 beta is set; null unless thinking.display resolves to "omitted" and a count is due this frame. Sum the increments across thinking_delta frames on this block for a progress indicator. Each increment is a non-negative multiple of a fixed quantum and the cadence is rate-limited, so this is a deliberately lossy display hint, not a billable count; usage.output_tokens remains authoritative.

thinking: str

The incremental thinking text for this content block. Concatenate the thinking values of successive thinking_delta events to assemble the block's full thinking value.

class BetaThinkingDroppedInputTransformation: type: "thinking_dropped"; path; reason
type: Literal["thinking_dropped"]

Always thinking_dropped for this entry type.

defaultthinking_dropped
path: str

Where the removed block was in your request, as messages.{i}.content.{j}: i indexes the messages array you sent and j that message's content array — the same form error messages use.

reason: Literal["model_binding_mismatch", "prefix_binding_mismatch", "organization_binding_mismatch", "end_user_binding_mismatch"]

Which binding check removed the block: model_binding_mismatch — it was created by a model whose reasoning the requested model may not read; prefix_binding_mismatch — the conversation before it differs from the conversation it was created in (the rest of that turn's consecutive thinking blocks are removed with it, each with this reason); organization_binding_mismatch — it was created under a different organization (an Anthropic organization, AWS account or Google Cloud project) and this organization is not one of its additional organizations; end_user_binding_mismatch — it was created for a different end user, or was removed by the consumer-organization binding. A block that would fail several checks reports one reason, in this order of precedence: organization_binding_mismatch, end_user_binding_mismatch, model_binding_mismatch, prefix_binding_mismatch.

One of the following:
"model_binding_mismatch"
"prefix_binding_mismatch"
"organization_binding_mismatch"
"end_user_binding_mismatch"
class BetaThinkingMismatchAllowedInputTransformation: type: "thinking_mismatch_allowed"; path; reason
type: Literal["thinking_mismatch_allowed"]

Always thinking_mismatch_allowed for this entry type.

defaultthinking_mismatch_allowed
path: str

Where the block is in your request, as messages.{i}.content.{j}: i indexes the messages array you sent and j that message's content array — the same form error messages use.

reason: Literal["model_binding_mismatch", "prefix_binding_mismatch", "organization_binding_mismatch", "end_user_binding_mismatch"]

Which binding check the block failed; the block was shown to the model all the same. Always prefix_binding_mismatch today — the conversation before the block differs from the conversation it was created in, or the block carries no record of one on a model that requires it. Were the check enforced for this request, the block would have been removed or the request rejected (thinking.block_binding.prefix_mismatch_behavior). A removal also takes the rest of that turn's consecutive thinking blocks, whereas here each block is checked on its own, so thinking_mismatch_allowed entries are a lower bound on what enforcement would remove.

One of the following:
"model_binding_mismatch"
"prefix_binding_mismatch"
"organization_binding_mismatch"
"end_user_binding_mismatch"
type BetaThinkingPrefixMismatchBehavior = Literal["error", "drop_block"]

What happens when a thinking block in messages fails the conversation check: it was created in a different conversation, or the messages before it have changed since. "error" (the default) fails the request with a 400 error. "drop_block" removes the failing blocks and the request proceeds; the model no longer sees the dropped reasoning.

One of the following:
"error"
"drop_block"
class BetaThinkingTurns: type: "thinking_turns"; value
type: Literal["thinking_turns"]
value: int
minimum1
class BetaTokenTaskBudget: type: "tokens"; total; remaining

User-configurable total token budget across contexts.

type: Literal["tokens"]

The budget type. Currently only 'tokens' is supported.

total: int

Total token budget across all contexts in the session.

minimum1024
remaining: Optional[int]

Remaining tokens in the budget. Use this to track usage across contexts when implementing compaction client-side. Defaults to total if not provided.

minimum0
class BetaTool: type; input_schema; name; ... # 7 more
class BetaToolBash20241022: type: "bash_20241022"; name; allowed_callers; ... # 4 more
class BetaToolBash20250124: type: "bash_20250124"; name; allowed_callers; ... # 4 more
class BetaToolChangeMCPToolReference: type: "mcp_tool_reference"; name; server_name

Reference to a single MCP tool by its server and remote name; the same server_name/name pair mcp_tool_use carries.

type: Literal["mcp_tool_reference"]
name: str
server_name: str
class BetaToolChangeMCPToolsetReference: type: "mcp_toolset_reference"; server_name

Reference to every tool in the named MCP server's toolset.

type: Literal["mcp_toolset_reference"]
server_name: str
class BetaToolChangeToolDefinition: type: "tool_definition"; definition

A tool defined by value, as a compaction block's tool_changes entry reports it: definition is the tool's definition as it was sent, in the form of a tools entry, without cache_control. Send it back unchanged with the block.

type: Literal["tool_definition"]
defaulttool_definition
definition: BetaResponseToolUnion
One of the following:
class BetaToolChangeToolDefinitionParam: type: "tool_definition"; definition

A tool defined by value: definition is a tools entry (any kind tools accepts, an MCP toolset included). An mcp_toolset given here also requires the mcp-client-2026-09-15 beta.

type: Literal["tool_definition"]
definition: BetaToolUnion
One of the following:
class BetaToolChangeToolReference: type: "tool_reference"; name

Reference to a single tool, by the name the model uses to call it: a tool declared in tools or defined by an earlier tool_addition block. Does not accept the composed {server}_{name} form the server assigns to MCP-resolved tools; use mcp_tool_reference or mcp_toolset_reference for those.

type: Literal["tool_reference"]
name: str
pattern^[a-zA-Z0-9_-]{1,128}$
type BetaToolChoice = ...

How the model should use the provided tools. The model can use a specific tool, any available tool, decide by itself, or not use tools at all.

One of the following:
class BetaToolChoiceAny: type: "any"; disable_parallel_tool_use

The model will use any available tools.

type: Literal["any"]
disable_parallel_tool_use: Optional[bool]

Whether to disable parallel tool use.

Defaults to false. If set to true, the model will output exactly one tool use.

class BetaToolChoiceAuto: type: "auto"; disable_parallel_tool_use

The model will automatically decide whether to use tools.

type: Literal["auto"]
disable_parallel_tool_use: Optional[bool]

Whether to disable parallel tool use.

Defaults to false. If set to true, the model will output at most one tool use.

class BetaToolChoiceNone: type: "none"

The model will not be allowed to use tools.

type: Literal["none"]
class BetaToolChoiceTool: type: "tool"; name; disable_parallel_tool_use

The model will use the specified tool with tool_choice.name.

type: Literal["tool"]
name: str

The name of the tool to use.

disable_parallel_tool_use: Optional[bool]

Whether to disable parallel tool use.

Defaults to false. If set to true, the model will output exactly one tool use.

class BetaToolComputerUse20241022: type: "computer_20241022"; display_height_px; display_width_px; ... # 7 more
class BetaToolComputerUse20250124: type: "computer_20250124"; display_height_px; display_width_px; ... # 7 more
class BetaToolComputerUse20251124: type: "computer_20251124"; display_height_px; display_width_px; ... # 8 more
class BetaToolReferenceBlock: type: "tool_reference"; tool_name
type: Literal["tool_reference"]
defaulttool_reference
tool_name: str
minLength1
maxLength256
pattern^[a-zA-Z0-9_-]{1,256}$
class BetaToolReferenceBlockParam: type: "tool_reference"; tool_name; cache_control

Tool reference block that can be included in tool_result content.

type: Literal["tool_reference"]
tool_name: str
minLength1
maxLength256
pattern^[a-zA-Z0-9_-]{1,256}$
cache_control: Optional[BetaCacheControlEphemeral]

Create a cache control breakpoint at this content block.

type: Literal["ephemeral"]
ttl: Optional[Literal["5m", "1h"]]

The time-to-live for the cache control breakpoint.

This may be one the following values:

  • 5m: 5 minutes
  • 1h: 1 hour

Defaults to 5m. See prompt caching pricing for details.

One of the following:
"5m"
"1h"
class BetaToolResultBlockParam: type: "tool_result"; tool_use_id; cache_control; ... # 3 more
class BetaToolSearchToolBm25_20251119: type; name; allowed_callers; ... # 3 more
class BetaToolSearchToolRegex20251119: type; name; allowed_callers; ... # 3 more
class BetaToolSearchToolResultBlock: type: "tool_search_tool_result"; content; tool_use_id
class BetaToolSearchToolResultBlockParam: type: "tool_search_tool_result"; content; tool_use_id; cache_control
class BetaToolSearchToolResultError: type: "tool_search_tool_result_error"; error_code; error_message
type: Literal["tool_search_tool_result_error"]
defaulttool_search_tool_result_error
error_code: Literal["invalid_tool_input", "unavailable", "too_many_requests", "execution_time_exceeded"]
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
error_message: Optional[str]
class BetaToolSearchToolResultErrorParam: type: "tool_search_tool_result_error"; error_code; error_message
type: Literal["tool_search_tool_result_error"]
error_code: Literal["invalid_tool_input", "unavailable", "too_many_requests", "execution_time_exceeded"]
One of the following:
"invalid_tool_input"
"unavailable"
"too_many_requests"
"execution_time_exceeded"
error_message: Optional[str]
class BetaToolSearchToolSearchResultBlock: type: "tool_search_tool_search_result"; tool_references
type: Literal["tool_search_tool_search_result"]
defaulttool_search_tool_search_result
tool_references: List[BetaToolReferenceBlock]
type: Literal["tool_reference"]
defaulttool_reference
tool_name: str
minLength1
maxLength256
pattern^[a-zA-Z0-9_-]{1,256}$
class BetaToolSearchToolSearchResultBlockParam: type: "tool_search_tool_search_result"; tool_references
class BetaToolTextEditor20241022: type: "text_editor_20241022"; name; allowed_callers; ... # 4 more
class BetaToolTextEditor20250124: type: "text_editor_20250124"; name; allowed_callers; ... # 4 more
class BetaToolTextEditor20250429: type: "text_editor_20250429"; name; allowed_callers; ... # 4 more
class BetaToolTextEditor20250728: type: "text_editor_20250728"; name; allowed_callers; ... # 5 more
type BetaToolUnion = ...
One of the following:
class BetaToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaToolUseBlockParam: type: "tool_use"; id; input; ... # 4 more
type BetaToolUseCaller = ...

Which party invoked the tool call: the model directly, or a server tool on its behalf.

One of the following:
class BetaDirectCaller: type: "direct"

Tool invocation directly from the model.

type: Literal["direct"]
class BetaServerToolCaller: type: "code_execution_20250825"; tool_id

Tool invocation generated by a server-side tool.

type: Literal["code_execution_20250825"]
tool_id: str
pattern^srvtoolu_[a-zA-Z0-9_]+$
class BetaServerToolCaller20260120: type: "code_execution_20260120"; tool_id
type: Literal["code_execution_20260120"]
tool_id: str
pattern^srvtoolu_[a-zA-Z0-9_]+$
class BetaToolUsesKeep: type: "tool_uses"; value
type: Literal["tool_uses"]
value: int
minimum0
class BetaToolUsesTrigger: type: "tool_uses"; value
type: Literal["tool_uses"]
value: int
minimum1
type BetaToolsetToolUseBlock = ...
One of the following:
type BetaBrowserToolUseBlock = ...
One of the following:
type BetaComputerToolUseBlock = ...
One of the following:
class BetaToolUseBlock: type: "tool_use"; id; input; ... # 3 more
class BetaURLImageSource: type: "url"; url
type: Literal["url"]
url: str
class BetaURLPDFSource: type: "url"; url
type: Literal["url"]
url: str
class BetaUsage: cache_creation; cache_creation_input_tokens; cache_read_input_tokens; ... # 9 more
class BetaUserLocation: type: "approximate"; city; country; ... # 2 more
type: Literal["approximate"]
city: Optional[str]

The city of the user.

minLength1
maxLength255
country: Optional[str]

The two letter ISO country code of the user.

minLength2
maxLength2
region: Optional[str]

The region of the user.

minLength1
maxLength255
timezone: Optional[str]

The IANA timezone of the user.

minLength1
maxLength255
class BetaWebFetchBlock: type: "web_fetch_result"; content; retrieved_at; url
type: Literal["web_fetch_result"]
defaultweb_fetch_result
content: BetaDocumentBlock
retrieved_at: Optional[str]

ISO 8601 timestamp when the content was retrieved

url: str

Fetched content URL

class BetaWebFetchBlockParam: type: "web_fetch_result"; content; url; retrieved_at
type: Literal["web_fetch_result"]
url: str

Fetched content URL

retrieved_at: Optional[str]

ISO 8601 timestamp when the content was retrieved

class BetaWebFetchTool20250910: type: "web_fetch_20250910"; name; allowed_callers; ... # 9 more
class BetaWebFetchTool20260209: type: "web_fetch_20260209"; name; allowed_callers; ... # 9 more
class BetaWebFetchTool20260309: type: "web_fetch_20260309"; name; allowed_callers; ... # 10 more

Web fetch tool with use_cache parameter for bypassing cached content.

class BetaWebFetchTool20260318: type: "web_fetch_20260318"; name; allowed_callers; ... # 11 more
class BetaWebFetchToolResultBlock: type: "web_fetch_tool_result"; content; tool_use_id; caller
class BetaWebFetchToolResultBlockParam: type: "web_fetch_tool_result"; content; tool_use_id; ... # 2 more
class BetaWebFetchToolResultErrorBlock: type: "web_fetch_tool_result_error"; error_code
type: Literal["web_fetch_tool_result_error"]
defaultweb_fetch_tool_result_error
One of the following:
"invalid_tool_input"
"url_too_long"
"url_not_allowed"
"url_not_in_prior_context"
"url_not_accessible"
"unsupported_content_type"
"too_many_requests"
"max_uses_exceeded"
"unavailable"
"content_too_large"
class BetaWebFetchToolResultErrorBlockParam: type: "web_fetch_tool_result_error"; error_code
type: Literal["web_fetch_tool_result_error"]
One of the following:
"invalid_tool_input"
"url_too_long"
"url_not_allowed"
"url_not_in_prior_context"
"url_not_accessible"
"unsupported_content_type"
"too_many_requests"
"max_uses_exceeded"
"unavailable"
"content_too_large"
type BetaWebFetchToolResultErrorCode = Literal["invalid_tool_input", "url_too_long", "url_not_allowed", 7 more]
One of the following:
"invalid_tool_input"
"url_too_long"
"url_not_allowed"
"url_not_in_prior_context"
"url_not_accessible"
"unsupported_content_type"
"too_many_requests"
"max_uses_exceeded"
"unavailable"
"content_too_large"
class BetaWebFetchURLSourceAll: type: "all"

The url_sources variant under which a source contributes in full: every result of the tool filter's source, or all user input.

type: Literal["all"]
class BetaWebFetchURLSourceExcept: type: "except"; tools

The tool filter variant under which every result but the named tools' contributes.

type: Literal["except"]
type: Literal["tool_reference"]
name: str
class BetaWebFetchURLSourceNone: type: "none"

The url_sources variant under which a source contributes nothing: no result of the tool filter's source, or no user input.

type: Literal["none"]
class BetaWebFetchURLSourceOnly: type: "only"; tools

The tool filter variant under which only the named tools' results contribute.

type: Literal["only"]
type: Literal["tool_reference"]
name: str
class BetaWebFetchURLSourceToolReference: type: "tool_reference"; name

One entry of a tool filter's tools: it must name a tool declared in this request's tools[].

type: Literal["tool_reference"]
name: str
class BetaWebFetchURLSources: client_tool_results; server_tool_results; user_input

Which sources contribute to the set of URLs web fetch may fetch.

Each key is a tagged variant: user_input is all or none; the two tool filters are all, none, only (only the named tools' results) or except (every result but the named tools'). A named tool must be declared in this request's tools[].

class BetaWebSearchResultBlock: type: "web_search_result"; encrypted_content; page_age; ... # 2 more
type: Literal["web_search_result"]
defaultweb_search_result
encrypted_content: str
page_age: Optional[str]
title: str
url: str
class BetaWebSearchResultBlockParam: type: "web_search_result"; encrypted_content; title; ... # 2 more
type: Literal["web_search_result"]
encrypted_content: str
title: str
url: str
page_age: Optional[str]
class BetaWebSearchTool20250305: type: "web_search_20250305"; name; allowed_callers; ... # 7 more
class BetaWebSearchTool20260209: type: "web_search_20260209"; name; allowed_callers; ... # 7 more
class BetaWebSearchTool20260318: type: "web_search_20260318"; name; allowed_callers; ... # 8 more
class BetaWebSearchToolRequestError: type: "web_search_tool_result_error"; error_code
type: Literal["web_search_tool_result_error"]
One of the following:
"invalid_tool_input"
"unavailable"
"max_uses_exceeded"
"too_many_requests"
"query_too_long"
"request_too_large"
class BetaWebSearchToolResultBlock: type: "web_search_tool_result"; content; tool_use_id; caller
type BetaWebSearchToolResultBlockContent = ...
One of the following:
class BetaWebSearchToolResultBlockParam: type: "web_search_tool_result"; content; tool_use_id; ... # 2 more
type BetaWebSearchToolResultBlockParamContent = ...
One of the following:
class BetaWebSearchToolResultError: type: "web_search_tool_result_error"; error_code
type: Literal["web_search_tool_result_error"]
defaultweb_search_tool_result_error
One of the following:
"invalid_tool_input"
"unavailable"
"max_uses_exceeded"
"too_many_requests"
"query_too_long"
"request_too_large"
type BetaWebSearchToolResultErrorCode = Literal["invalid_tool_input", "unavailable", "max_uses_exceeded", 3 more]
One of the following:
"invalid_tool_input"
"unavailable"
"max_uses_exceeded"
"too_many_requests"
"query_too_long"
"request_too_large"

消息批处理

创建消息批次
beta.messages.batches.create(**kwargs) -> BetaMessageBatch
POST/v1/messages/batches

发送一批消息创建请求。

检索消息批次
beta.messages.batches.retrieve(message_batch_id, **kwargs) -> BetaMessageBatch
GET/v1/messages/batches/{message_batch_id}

此端点是幂等的,可用于轮询消息批次是否完成。要访问消息批次的结果,请向响应中的 results_url 字段发起请求。

列出消息批次
beta.messages.batches.list(**kwargs) -> SyncPage[BetaMessageBatch]
GET/v1/messages/batches

列出工作区内的所有消息批次。最近创建的批次最先返回。

取消消息批次
beta.messages.batches.cancel(message_batch_id, **kwargs) -> BetaMessageBatch
POST/v1/messages/batches/{message_batch_id}/cancel

批次可在处理结束前的任何时间取消。一旦发起取消,批次将进入 canceling 状态,此时系统可能会先完成任何正在进行的、不可中断的请求,然后再最终完成取消。

删除消息批次
beta.messages.batches.delete(message_batch_id, **kwargs) -> BetaDeletedMessageBatch
DELETE/v1/messages/batches/{message_batch_id}

删除消息批次。

检索消息批次结果
beta.messages.batches.results(message_batch_id, **kwargs) -> BetaMessageBatchIndividualResponse
GET/v1/messages/batches/{message_batch_id}/results

以 .jsonl 文件的形式流式传输消息批次的结果。