Count tokens in a Message

POST /v1/messages/count_tokens

Count the number of tokens in a Message.

The Token Count API can be used to count the number of tokens in a Message, including tools, images, and documents, without creating it.

Learn more about token counting in our user guide

Headers

"juglow-user-profile-id": optional string

The user profile ID to attribute this request to. Use when acting on behalf of a party other than your organization. Requires the user-profiles beta header.

"juglow-workspace-id": optional string

Optional header to select the Workspace for this request. The value is a Workspace ID (for example, wrkspc_011CZkZaBF1tNoB5wlCeusgy).

Only needed for credentials that can act on more than one Workspace. A credential that belongs to a specific Workspace may omit it; if sent, it must match that Workspace.

Body parameters

messages: array of MessageParam

Input messages.

Our models are trained to operate on alternating user and assistant conversational turns. When creating a new Message, you specify the prior conversational turns with the messages parameter, and the model then generates the next Message in the conversation. Consecutive user or assistant turns in your request will be combined into a single turn.

Each input message must be an object with a role and content. You can specify a single user-role message, or you can include multiple user and assistant messages.

If the final message uses the assistant role, the response content will continue immediately from the content in that message. This can be used to constrain part of the model's response.

Example with a single user message:

json

  [{"role": "user", "content": "Hello, Haijun"}]

Example with multiple conversational turns:

json

  [
    {"role": "user", "content": "Hello there."},
    {"role": "assistant", "content": "Hi, I'm Haijun. How can I help you?"},
    {"role": "user", "content": "Can you explain LLMs in plain English?"},
  ]

Example with a partially-filled response from Haijun:

json

  [
    {"role": "user", "content": "What's the Greek name for Sun? (A) Sol (B) Helios (C) Sun"},
    {"role": "assistant", "content": "The best answer is ("},
  ]

Each input message content may be either a single string or an array of content blocks, where each block has a specific type. Using a string for content is shorthand for an array of one content block of type "text". The following input messages are equivalent:

json

  {"role": "user", "content": "Hello, Haijun"}

json

  {"role": "user", "content": [{"type": "text", "text": "Hello, Haijun"}]}

See input examples.

Note that if you want to include a system prompt, you can use the top-level system parameter — there is no "system" role for input messages in the Messages API.

There is a limit of 100,000 messages in a single request.

content: string or array of ContentBlockParam

string

array of ContentBlockParam

TextBlockParam object

type: "text"

text: string

minLength: 1

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

type: "ephemeral"

ttl: optional "5m" or "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.

"5m"

"1h"

citations: optional array of TextCitationParam or null

CitationCharLocationParam object

type: "char_location"

cited_text: string

document_index: number

minimum: 0

document_title: string or null

minLength: 1, maxLength: 500

end_char_index: number

start_char_index: number

minimum: 0

CitationPageLocationParam object

type: "page_location"

cited_text: string

document_index: number

minimum: 0

document_title: string or null

minLength: 1, maxLength: 500

end_page_number: number

start_page_number: number

minimum: 1

CitationContentBlockLocationParam object

type: "content_block_location"

cited_text: string

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: number

minimum: 0

document_title: string or null

minLength: 1, maxLength: 500

end_block_index: number

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: number

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

minimum: 0

CitationWebSearchResultLocationParam object

type: "web_search_result_location"

cited_text: string

encrypted_index: string

title: string or null

minLength: 1, maxLength: 512

url: string

minLength: 1

CitationSearchResultLocationParam object

type: "search_result_location"

cited_text: string

The full text of the cited block range, concatenated.

end_block_index: number

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: number

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.

minimum: 0

source: string

start_block_index: number

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

minimum: 0

title: string or null

ImageBlockParam object

type: "image"

source: Base64ImageSource or URLImageSource or FileImageSource

Base64ImageSource object

type: "base64"

data: string

format: byte

media_type: "image/jpeg" or "image/png" or "image/gif" or "image/webp"

"image/jpeg"

"image/png"

"image/gif"

"image/webp"

URLImageSource object

type: "url"

url: string

FileImageSource object

type: "file"

file_id: string

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

transformations: optional ImageTransformationsParam or null

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 "downsize" or "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.

"downsize"

"error"

DocumentBlockParam object

type: "document"

source: Base64PDFSource or PlainTextSource or ContentBlockSource or 2 more

Base64PDFSource object

type: "base64"

data: string

format: byte

media_type: "application/pdf"

PlainTextSource object

type: "text"

data: string

media_type: "text/plain"

ContentBlockSource object

type: "content"

content: string or array of ContentBlockSourceContent

string

ContentBlockSourceContent = array of ContentBlockSourceContent

TextBlockParam object

ImageBlockParam object

URLPDFSource object

type: "url"

url: string

FileDocumentSource object

type: "file"

file_id: string

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

citations: optional CitationsConfigParam or null

enabled: optional boolean

context: optional string or null

minLength: 1

title: optional string or null

minLength: 1, maxLength: 500

SearchResultBlockParam object

type: "search_result"

content: array of TextBlockParam

type: "text"

text: string

minLength: 1

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

citations: optional array of TextCitationParam or null

source: string

title: string

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

citations: optional CitationsConfigParam

ThinkingBlockParam object

type: "thinking"

signature: string

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 Haijun.

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

thinking: string

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

RedactedThinkingBlockParam object

type: "redacted_thinking"

data: string

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.

ToolUseBlockParam object

type: "tool_use"

id: string

pattern: ^[a-zA-Z0-9_-]+$

input: map[unknown]

name: string

minLength: 1, maxLength: 200

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

caller: optional DirectCaller or ServerToolCaller or ServerToolCaller20260120

DirectCaller object

Tool invocation directly from the model.

type: "direct"

ServerToolCaller object

Tool invocation generated by a server-side tool.

type: "code_execution_20250825"

tool_id: string

pattern: ^srvtoolu_[a-zA-Z0-9_]+$

ServerToolCaller20260120 object

type: "code_execution_20260120"

tool_id: string

pattern: ^srvtoolu_[a-zA-Z0-9_]+$

toolset_name: optional string or null

For a toolset member tool_use, the toolset family this member belongs to.

minLength: 1, maxLength: 64, pattern: ^[a-zA-Z0-9_-]+$

ToolResultBlockParam object

type: "tool_result"

tool_use_id: string

pattern: ^[a-zA-Z0-9_-]+$

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

content: optional string or array of TextBlockParam or ImageBlockParam or SearchResultBlockParam or 3 more

string

array of TextBlockParam or ImageBlockParam or SearchResultBlockParam or 3 more

TextBlockParam object

ImageBlockParam object

SearchResultBlockParam object

DocumentBlockParam object

ToolReferenceBlockParam object

Tool reference block that can be included in tool_result content.

type: "tool_reference"

tool_name: string

minLength: 1, maxLength: 256, pattern: ^[a-zA-Z0-9_-]{1,256}$

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

BrowserStateBlockParam object

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: "browser_state"

tabs: array of BrowserStateTabEntry

All tabs open in the browser after this call — the full inventory, not a delta. May be empty. Whenever non-empty, exactly one entry carries active: true.

maxItems: 100

tab_id: string

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

minLength: 1, maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

title: string

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

maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

url: string

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

maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

active: optional boolean

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

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

state_changes: optional array of BrowserStateChange or null

Tabs opened and download state changes during this call. "Nothing to report" is expressed by omitting the field, never by an empty list.

minItems: 1, maxItems: 200

BrowserStateChangeTabOpened object

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: "tab_opened"

tab_id: string

The tab_id of the opened tab, present in tabs.

minLength: 1, maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

BrowserStateChangeDownloadStarted object

A file download that started during this call.

type: "download_started"

download_id: string

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

minLength: 1, maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

url: string

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

maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

BrowserStateChangeDownloadCompleted object

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: "download_completed"

download_id: string

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

minLength: 1, maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

url: string

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

maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

path: optional string or null

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.

maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

size_bytes: optional number or null

The completed download's size.

minimum: 0

BrowserStateChangeDownloadFailed object

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

type: "download_failed"

download_id: string

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

minLength: 1, maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

url: string

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

maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

error: optional string or null

The failure or cancellation detail, when known.

maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$

is_error: optional boolean

toolset_name: optional string or null

For a toolset member tool_result, the toolset family of the paired tool_use.

minLength: 1, maxLength: 64, pattern: ^[a-zA-Z0-9_-]+$

ServerToolUseBlockParam object

type: "server_tool_use"

id: string

pattern: ^srvtoolu_[a-zA-Z0-9_]+$

input: map[unknown]

name: "web_search" or "web_fetch" or "code_execution" or 4 more

"web_search"

"web_fetch"

"code_execution"

"bash_code_execution"

"text_editor_code_execution"

"tool_search_tool_regex"

"tool_search_tool_bm25"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

caller: optional DirectCaller or ServerToolCaller or ServerToolCaller20260120

DirectCaller object

Tool invocation directly from the model.

ServerToolCaller object

Tool invocation generated by a server-side tool.

ServerToolCaller20260120 object

WebSearchToolResultBlockParam object

type: "web_search_tool_result"

content: WebSearchToolResultBlockParamContent

WebSearchToolResultBlockItem = array of WebSearchResultBlockParam

type: "web_search_result"

encrypted_content: string

title: string

url: string

page_age: optional string or null

WebSearchToolRequestError object

type: "web_search_tool_result_error"

error_code: WebSearchToolResultErrorCode

"invalid_tool_input"

"unavailable"

"max_uses_exceeded"

"too_many_requests"

"query_too_long"

"request_too_large"

tool_use_id: string

pattern: ^srvtoolu_[a-zA-Z0-9_]+$

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

caller: optional DirectCaller or ServerToolCaller or ServerToolCaller20260120

DirectCaller object

Tool invocation directly from the model.

ServerToolCaller object

Tool invocation generated by a server-side tool.

ServerToolCaller20260120 object

WebFetchToolResultBlockParam object

type: "web_fetch_tool_result"

content: WebFetchToolResultErrorBlockParam or WebFetchBlockParam

WebFetchToolResultErrorBlockParam object

type: "web_fetch_tool_result_error"

error_code: WebFetchToolResultErrorCode

"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"

WebFetchBlockParam object

type: "web_fetch_result"

content: DocumentBlockParam

url: string

Fetched content URL

retrieved_at: optional string or null

ISO 8601 timestamp when the content was retrieved

tool_use_id: string

pattern: ^srvtoolu_[a-zA-Z0-9_]+$

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

caller: optional DirectCaller or ServerToolCaller or ServerToolCaller20260120

DirectCaller object

Tool invocation directly from the model.

ServerToolCaller object

Tool invocation generated by a server-side tool.

ServerToolCaller20260120 object

CodeExecutionToolResultBlockParam object

type: "code_execution_tool_result"

content: CodeExecutionToolResultBlockParamContent

CodeExecutionToolResultErrorParam object

type: "code_execution_tool_result_error"

error_code: CodeExecutionToolResultErrorCode

"invalid_tool_input"

"unavailable"

"too_many_requests"

"execution_time_exceeded"

CodeExecutionResultBlockParam object

type: "code_execution_result"

content: array of CodeExecutionOutputBlockParam

type: "code_execution_output"

file_id: string

return_code: number

stderr: string

stdout: string

EncryptedCodeExecutionResultBlockParam object

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

type: "encrypted_code_execution_result"

content: array of CodeExecutionOutputBlockParam

type: "code_execution_output"

file_id: string

encrypted_stdout: string

return_code: number

stderr: string

tool_use_id: string

pattern: ^srvtoolu_[a-zA-Z0-9_]+$

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

BashCodeExecutionToolResultBlockParam object

type: "bash_code_execution_tool_result"

content: BashCodeExecutionToolResultErrorParam or BashCodeExecutionResultBlockParam

BashCodeExecutionToolResultErrorParam object

type: "bash_code_execution_tool_result_error"

error_code: BashCodeExecutionToolResultErrorCode

"invalid_tool_input"

"unavailable"

"too_many_requests"

"execution_time_exceeded"

"output_file_too_large"

BashCodeExecutionResultBlockParam object

type: "bash_code_execution_result"

content: array of BashCodeExecutionOutputBlockParam

type: "bash_code_execution_output"

file_id: string

return_code: number

stderr: string

stdout: string

tool_use_id: string

pattern: ^srvtoolu_[a-zA-Z0-9_]+$

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

TextEditorCodeExecutionToolResultBlockParam object

type: "text_editor_code_execution_tool_result"

content: TextEditorCodeExecutionToolResultErrorParam or TextEditorCodeExecutionViewResultBlockParam or TextEditorCodeExecutionCreateResultBlockParam or TextEditorCodeExecutionStrReplaceResultBlockParam

TextEditorCodeExecutionToolResultErrorParam object

type: "text_editor_code_execution_tool_result_error"

error_code: TextEditorCodeExecutionToolResultErrorCode

"invalid_tool_input"

"unavailable"

"too_many_requests"

"execution_time_exceeded"

"file_not_found"

error_message: optional string or null

TextEditorCodeExecutionViewResultBlockParam object

type: "text_editor_code_execution_view_result"

content: string

file_type: "text" or "image" or "pdf"

"text"

"image"

"pdf"

num_lines: optional number or null

start_line: optional number or null

total_lines: optional number or null

TextEditorCodeExecutionCreateResultBlockParam object

type: "text_editor_code_execution_create_result"

is_file_update: boolean

TextEditorCodeExecutionStrReplaceResultBlockParam object

type: "text_editor_code_execution_str_replace_result"

lines: optional array of string or null

new_lines: optional number or null

new_start: optional number or null

old_lines: optional number or null

old_start: optional number or null

tool_use_id: string

pattern: ^srvtoolu_[a-zA-Z0-9_]+$

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

ToolSearchToolResultBlockParam object

type: "tool_search_tool_result"

content: ToolSearchToolResultErrorParam or ToolSearchToolSearchResultBlockParam

ToolSearchToolResultErrorParam object

type: "tool_search_tool_result_error"

error_code: ToolSearchToolResultErrorCode

"invalid_tool_input"

"unavailable"

"too_many_requests"

"execution_time_exceeded"

error_message: optional string or null

ToolSearchToolSearchResultBlockParam object

type: "tool_search_tool_search_result"

tool_references: array of ToolReferenceBlockParam

type: "tool_reference"

tool_name: string

minLength: 1, maxLength: 256, pattern: ^[a-zA-Z0-9_-]{1,256}$

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

tool_use_id: string

pattern: ^srvtoolu_[a-zA-Z0-9_]+$

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

ContainerUploadBlockParam object

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: "container_upload"

file_id: string

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

role: "user" or "assistant" or "system"

"user"

"assistant"

"system"

model: Model

The model that will complete your prompt.

See models for additional details and options.

string

"haijun-fable-5-1" or "haijun-opus-5-5" or "haijun-mythos-5-1" or 15 more

The model that will complete your prompt.

See models for additional details and options.

"haijun-fable-5-1"

Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows

"haijun-opus-5-5"

Powerful intelligence for coding, knowledge work, and long-running agents

"haijun-mythos-5-1"

Our most capable model for cybersecurity and biology research, available through trusted access programs

"haijun-sonnet-5"

High-performance model for coding and agents

"haijun-fable-5"

Next generation of intelligence for the hardest knowledge work and coding problems

"haijun-mythos-5"

Most capable model for cybersecurity and biology research

"haijun-opus-5"

Powerful intelligence for long-running agents and coding

"haijun-opus-4-8"

Powerful intelligence for long-running agents and coding

"haijun-opus-4-7"

Powerful intelligence for long-running agents and coding

"haijun-opus-4-6"

Powerful intelligence for long-running agents and coding

"haijun-sonnet-4-6"

Best combination of speed and intelligence

"haijun-haiku-4-5"

Fastest model with near-frontier intelligence

"haijun-haiku-4-5-20251001"

Fastest model with near-frontier intelligence

"haijun-opus-4-5"

Powerful intelligence for long-running agents and coding

"haijun-opus-4-5-20251101"

Powerful intelligence for long-running agents and coding

"haijun-sonnet-4-5"

High-performance model for agents and coding

"haijun-sonnet-4-5-20250929"

High-performance model for agents and coding

"haijun-mythos-preview"

Deprecated: Will reach end-of-life on June 30, 2026. Please migrate to haijun-mythos-5. Visit https://raw.haijun.my.id/docs/ for more information.

New class of intelligence, strongest in coding and cybersecurity

cache_control: optional CacheControlEphemeral or null

Top-level cache control automatically applies a cache_control marker to the last cacheable block in the request.

output_config: optional OutputConfig

Configuration options for the model's output, such as the output format.

effort: optional "low" or "medium" or "high" or 2 more or null

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.

"low"

"medium"

"high"

"xhigh"

"max"

format: optional JSONOutputFormat or null

A schema to specify Haijun's output format in responses. See structured outputs

type: "json_schema"

schema: map[unknown]

The JSON schema of the format

system: optional string or array of TextBlockParam

System prompt.

A system prompt is a way of providing context and instructions to Haijun, such as specifying a particular goal or role. See our guide to system prompts.

string

array of TextBlockParam

type: "text"

text: string

minLength: 1

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

citations: optional array of TextCitationParam or null

thinking: optional ThinkingConfigParam

Configuration for enabling Haijun's extended thinking.

When enabled, responses include thinking content blocks showing Haijun's thinking process before the final answer. Requires a minimum budget of 1,024 tokens and counts towards your max_tokens limit.

See extended thinking for details.

ThinkingConfigEnabled object

type: "enabled"

budget_tokens: number

Determines how many tokens Haijun can use for its internal reasoning process. Larger budgets can enable more thorough analysis for complex problems, improving response quality.

Must be ≥1024 and less than max_tokens.

See extended thinking for details.

minimum: 1024

display: optional "summarized" or "omitted" or null

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. Defaults to summarized.

"summarized"

"omitted"

ThinkingConfigDisabled object

type: "disabled"

ThinkingConfigAdaptive object

type: "adaptive"

display: optional "summarized" or "omitted" or null

"summarized"

"omitted"

tool_choice: optional ToolChoice

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.

ToolChoiceAuto object

The model will automatically decide whether to use tools.

type: "auto"

disable_parallel_tool_use: optional boolean

Whether to disable parallel tool use.

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

ToolChoiceAny object

The model will use any available tools.

type: "any"

disable_parallel_tool_use: optional boolean

Whether to disable parallel tool use.

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

ToolChoiceTool object

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

type: "tool"

name: string

The name of the tool to use.

disable_parallel_tool_use: optional boolean

Whether to disable parallel tool use.

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

ToolChoiceNone object

The model will not be allowed to use tools.

type: "none"

tools: optional array of MessageCountTokensTool

Definitions of tools that the model may use.

If you include tools in your API request, the model may return tool_use content blocks that represent the model's use of those tools. You can then run those tools using the tool input generated by the model and then optionally return results back to the model using tool_result content blocks.

There are two types of tools: client tools and server tools. The behavior described below applies to client tools. For server tools, see their individual documentation as each has its own behavior (e.g., the web search tool).

Each tool definition includes:

name: Name of the tool.
description: Optional, but strongly-recommended description of the tool.
input_schema: JSON schema for the tool input shape that the model will produce in tool_use output content blocks.

For example, if you defined tools as:

json

  [
    {
      "name": "get_stock_price",
      "description": "Get the current stock price for a given ticker symbol.",
      "input_schema": {
        "type": "object",
        "properties": {
          "ticker": {
            "type": "string",
            "description": "The stock ticker symbol, e.g. AAPL for Apple Inc."
          }
        },
        "required": ["ticker"]
      }
    }
  ]

And then asked the model "What's the S&P 500 at today?", the model might produce tool_use content blocks in the response like this:

json

  [
    {
      "type": "tool_use",
      "id": "toolu_01D7FLrfh4GYq7yT1ULFeyMV",
      "name": "get_stock_price",
      "input": { "ticker": "^GSPC" }
    }
  ]

You might then run your get_stock_price tool with {"ticker": "^GSPC"} as an input, and return the following back to the model in a subsequent user message:

json

  [
    {
      "type": "tool_result",
      "tool_use_id": "toolu_01D7FLrfh4GYq7yT1ULFeyMV",
      "content": "259.75 USD"
    }
  ]

Tools can be used for workflows that include running client-side tools and functions, or more generally whenever you want the model to produce a particular JSON structure of output.

See our guide for more details.

Tool object

type: optional "custom" or null

input_schema: object

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: "object"

properties: optional map[unknown] or null

required: optional array of string or null

name: string

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

minLength: 1, maxLength: 128, pattern: ^[a-zA-Z0-9_-]{1,128}$

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

description: optional string

Description of what this tool does.

Tool descriptions should be as detailed as possible. The more information that the model has about what the tool is and how to use it, the better it will perform. You can use natural language descriptions to reinforce important aspects of the tool input JSON schema.

eager_input_streaming: optional boolean or null

Enable eager input streaming for this tool. When true, tool input parameters will be streamed incrementally as they are generated, and types will be inferred on-the-fly rather than buffering the full JSON output. When false, streaming is disabled for this tool even if the fine-grained-tool-streaming beta is active. When null (default), uses the default behavior based on beta headers.

input_examples: optional array of map[unknown]

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

ToolBash20250124 object

type: "bash_20250124"

name: "bash"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

input_examples: optional array of map[unknown]

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

CodeExecutionTool20250522 object

type: "code_execution_20250522"

name: "code_execution"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

CodeExecutionTool20250825 object

type: "code_execution_20250825"

name: "code_execution"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

CodeExecutionTool20260120 object

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

type: "code_execution_20260120"

name: "code_execution"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

CodeExecutionTool20260521 object

Code execution tool with REPL state persistence.

type: "code_execution_20260521"

name: "code_execution"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

BrowserToolset20260801 object

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: "browser_toolset_20260801"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

configs: optional BrowserToolsetConfigs or null

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

type: optional BrowserTypeConfig or null

type's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

close_tab: optional BrowserCloseTabConfig or null

close_tab's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

double_click: optional BrowserDoubleClickConfig or null

double_click's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

file_upload: optional BrowserFileUploadConfig or null

file_upload's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

find: optional BrowserFindConfig or null

find's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

form_input: optional BrowserFormInputConfig or null

form_input's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

get_page_text: optional BrowserGetPageTextConfig or null

get_page_text's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

hold_key: optional BrowserHoldKeyConfig or null

hold_key's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

hover: optional BrowserHoverConfig or null

hover's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

javascript_exec: optional BrowserJavascriptExecConfig or null

javascript_exec's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

key: optional BrowserKeyConfig or null

key's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

left_click: optional BrowserLeftClickConfig or null

left_click's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

left_click_drag: optional BrowserLeftClickDragConfig or null

left_click_drag's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

left_mouse_down: optional BrowserLeftMouseDownConfig or null

left_mouse_down's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

left_mouse_up: optional BrowserLeftMouseUpConfig or null

left_mouse_up's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

list_tabs: optional BrowserListTabsConfig or null

list_tabs's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

middle_click: optional BrowserMiddleClickConfig or null

middle_click's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

mouse_move: optional BrowserMouseMoveConfig or null

mouse_move's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

navigate: optional BrowserNavigateConfig or null

navigate's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

new_tab: optional BrowserNewTabConfig or null

new_tab's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

read_console: optional BrowserReadConsoleConfig or null

read_console's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

read_network: optional BrowserReadNetworkConfig or null

read_network's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

read_page: optional BrowserReadPageConfig or null

read_page's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

right_click: optional BrowserRightClickConfig or null

right_click's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

screenshot: optional BrowserScreenshotConfig or null

screenshot's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

scroll: optional BrowserScrollConfig or null

scroll's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

scroll_to: optional BrowserScrollToConfig or null

scroll_to's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

switch_tab: optional BrowserSwitchTabConfig or null

switch_tab's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

triple_click: optional BrowserTripleClickConfig or null

triple_click's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

wait: optional BrowserWaitConfig or null

wait's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

zoom: optional BrowserZoomConfig or null

zoom's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

MemoryTool20250818 object

type: "memory_20250818"

name: "memory"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

input_examples: optional array of map[unknown]

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

ComputerToolset20260801 object

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: "computer_toolset_20260801"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

configs: optional ComputerToolsetConfigs or null

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

type: optional ComputerTypeConfig or null

type's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

cursor_position: optional ComputerCursorPositionConfig or null

cursor_position's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

double_click: optional ComputerDoubleClickConfig or null

double_click's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

hold_key: optional ComputerHoldKeyConfig or null

hold_key's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

key: optional ComputerKeyConfig or null

key's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

left_click: optional ComputerLeftClickConfig or null

left_click's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

left_click_drag: optional ComputerLeftClickDragConfig or null

left_click_drag's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

left_mouse_down: optional ComputerLeftMouseDownConfig or null

left_mouse_down's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

left_mouse_up: optional ComputerLeftMouseUpConfig or null

left_mouse_up's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

middle_click: optional ComputerMiddleClickConfig or null

middle_click's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

mouse_move: optional ComputerMouseMoveConfig or null

mouse_move's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

right_click: optional ComputerRightClickConfig or null

right_click's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

screenshot: optional ComputerScreenshotConfig or null

screenshot's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

scroll: optional ComputerScrollConfig or null

scroll's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

triple_click: optional ComputerTripleClickConfig or null

triple_click's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

wait: optional ComputerWaitConfig or null

wait's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

zoom: optional ComputerZoomConfig or null

zoom's config overrides.

defer_loading: optional boolean or null

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

enabled: optional boolean or null

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.

ToolTextEditor20250124 object

type: "text_editor_20250124"

name: "str_replace_editor"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

input_examples: optional array of map[unknown]

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

ToolTextEditor20250429 object

type: "text_editor_20250429"

name: "str_replace_based_edit_tool"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

input_examples: optional array of map[unknown]

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

ToolTextEditor20250728 object

type: "text_editor_20250728"

name: "str_replace_based_edit_tool"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

input_examples: optional array of map[unknown]

max_characters: optional number or null

Maximum number of characters to display when viewing a file. If not specified, defaults to displaying the full file.

minimum: 1

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

WebSearchTool20250305 object

type: "web_search_20250305"

name: "web_search"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

allowed_domains: optional array of string or null

If provided, only these domains will be included in results. Cannot be used alongside blocked_domains.

blocked_domains: optional array of string or null

If provided, these domains will never appear in results. Cannot be used alongside allowed_domains.

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

max_uses: optional number or null

Maximum number of times the tool can be used in the API request.

minimum: 1

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

user_location: optional UserLocation or null

Parameters for the user's location. Used to provide more relevant search results.

type: "approximate"

city: optional string or null

The city of the user.

minLength: 1, maxLength: 255

country: optional string or null

The two letter ISO country code of the user.

minLength: 2, maxLength: 2

region: optional string or null

The region of the user.

minLength: 1, maxLength: 255

timezone: optional string or null

The IANA timezone of the user.

minLength: 1, maxLength: 255

WebFetchTool20250910 object

type: "web_fetch_20250910"

name: "web_fetch"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

allowed_domains: optional array of string or null

List of domains to allow fetching from

blocked_domains: optional array of string or null

List of domains to block fetching from

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

citations: optional CitationsConfigParam or null

Citations configuration for fetched documents. Citations are disabled by default.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

max_content_tokens: optional number or null

Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.

minimum: 1

max_uses: optional number or null

Maximum number of times the tool can be used in the API request.

minimum: 1

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

url_sources: optional WebFetchURLSources or null

Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.

client_tool_results: optional WebFetchURLSourceAll or WebFetchURLSourceNone or WebFetchURLSourceOnly or WebFetchURLSourceExcept

Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].

WebFetchURLSourceAll object

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

type: "all"

WebFetchURLSourceNone object

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

type: "none"

WebFetchURLSourceOnly object

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

type: "only"

tools: array of WebFetchURLSourceToolReference

type: "tool_reference"

name: string

WebFetchURLSourceExcept object

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

type: "except"

tools: array of WebFetchURLSourceToolReference

type: "tool_reference"

name: string

server_tool_results: optional WebFetchURLSourceAll or WebFetchURLSourceNone or WebFetchURLSourceOnly or WebFetchURLSourceExcept

Which server tools' results contribute fetchable URLs: "all", "none", or an only or except list of server tool names from tools[]; only web_search and web_fetch results ever contribute.

WebFetchURLSourceAll object

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

WebFetchURLSourceNone object

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

WebFetchURLSourceOnly object

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

WebFetchURLSourceExcept object

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

user_input: optional WebFetchURLSourceAll or WebFetchURLSourceNone

Whether URLs in user messages are fetchable: "all" or "none".

WebFetchURLSourceAll object

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

WebFetchURLSourceNone object

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

WebSearchTool20260209 object

type: "web_search_20260209"

name: "web_search"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

allowed_domains: optional array of string or null

If provided, only these domains will be included in results. Cannot be used alongside blocked_domains.

blocked_domains: optional array of string or null

If provided, these domains will never appear in results. Cannot be used alongside allowed_domains.

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

max_uses: optional number or null

Maximum number of times the tool can be used in the API request.

minimum: 1

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

user_location: optional UserLocation or null

Parameters for the user's location. Used to provide more relevant search results.

WebFetchTool20260209 object

type: "web_fetch_20260209"

name: "web_fetch"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

allowed_domains: optional array of string or null

List of domains to allow fetching from

blocked_domains: optional array of string or null

List of domains to block fetching from

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

citations: optional CitationsConfigParam or null

Citations configuration for fetched documents. Citations are disabled by default.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

max_content_tokens: optional number or null

Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.

minimum: 1

max_uses: optional number or null

Maximum number of times the tool can be used in the API request.

minimum: 1

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

url_sources: optional WebFetchURLSources or null

Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.

WebFetchTool20260309 object

Web fetch tool with use_cache parameter for bypassing cached content.

type: "web_fetch_20260309"

name: "web_fetch"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

allowed_domains: optional array of string or null

List of domains to allow fetching from

blocked_domains: optional array of string or null

List of domains to block fetching from

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

citations: optional CitationsConfigParam or null

Citations configuration for fetched documents. Citations are disabled by default.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

max_content_tokens: optional number or null

Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.

minimum: 1

max_uses: optional number or null

Maximum number of times the tool can be used in the API request.

minimum: 1

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

url_sources: optional WebFetchURLSources or null

Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.

use_cache: optional boolean

Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.

WebSearchTool20260318 object

type: "web_search_20260318"

name: "web_search"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

allowed_domains: optional array of string or null

If provided, only these domains will be included in results. Cannot be used alongside blocked_domains.

blocked_domains: optional array of string or null

If provided, these domains will never appear in results. Cannot be used alongside allowed_domains.

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

max_uses: optional number or null

Maximum number of times the tool can be used in the API request.

minimum: 1

response_inclusion: optional "full" or "excluded"

How this tool's result blocks appear in the API response when the result was consumed by a completed code_execution call in the same turn. 'full' returns the complete content (default). 'excluded' drops the nested server_tool_use and result block pair entirely. Results from direct calls, or from code_execution calls that paused before completing, are always returned in full so they can be sent back on the next turn.

"full"

"excluded"

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

user_location: optional UserLocation or null

Parameters for the user's location. Used to provide more relevant search results.

WebFetchTool20260318 object

type: "web_fetch_20260318"

name: "web_fetch"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

allowed_domains: optional array of string or null

List of domains to allow fetching from

blocked_domains: optional array of string or null

List of domains to block fetching from

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

citations: optional CitationsConfigParam or null

Citations configuration for fetched documents. Citations are disabled by default.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

max_content_tokens: optional number or null

Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.

minimum: 1

max_uses: optional number or null

Maximum number of times the tool can be used in the API request.

minimum: 1

response_inclusion: optional "full" or "excluded"

"full"

"excluded"

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

url_sources: optional WebFetchURLSources or null

Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.

use_cache: optional boolean

Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.

ToolSearchToolBm25_20251119 object

type: "tool_search_tool_bm25_20251119" or "tool_search_tool_bm25"

"tool_search_tool_bm25_20251119"

"tool_search_tool_bm25"

name: "tool_search_tool_bm25"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

ToolSearchToolRegex20251119 object

type: "tool_search_tool_regex_20251119" or "tool_search_tool_regex"

"tool_search_tool_regex_20251119"

"tool_search_tool_regex"

name: "tool_search_tool_regex"

Name of the tool.

This is how the tool will be called by the model and in tool_use blocks.

allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"

"direct"

"code_execution_20250825"

"code_execution_20260120"

"code_execution_20260521"

cache_control: optional CacheControlEphemeral or null

Create a cache control breakpoint at this content block.

defer_loading: optional boolean

If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.

strict: optional boolean

When true, guarantees schema validation on tool names and inputs

Returns

MessageTokensCount object

input_tokens: number

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

Example

bash

curl https://haijun.my.id/v1/messages/count_tokens \
    -H 'Content-Type: application/json' \
    -H 'juglow-version: 2023-06-01' \
    -H "X-Api-Key: $JUGLOW_API_KEY" \
    -d '{
          "messages": [
            {
              "content": "Hello, world",
              "role": "user"
            }
          ],
          "model": "haijun-opus-5",
          "system": [
            {
              "text": "Today'\''s date is 2024-06-01.",
              "type": "text"
            }
          ],
          "thinking": {
            "type": "adaptive"
          },
          "tools": [
            {
              "input_schema": {
                "type": "object",
                "properties": {
                  "location": "bar",
                  "unit": "bar"
                },
                "required": [
                  "location"
                ]
              },
              "name": "name"
            }
          ]
        }'

Response (200)

json

{
  "input_tokens": 2095
}

#Headers

#Body parameters

#Returns

#Example

#Response (200)

Headers

Body parameters

Returns

Example

Response (200)