Anthropic native Messages Token Count API

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https://cn2us02.opapi.win

POST

/v1/messages/count_tokens

API for calculating Input Tokens officially provided by Anthropic

The usage method is almost identical to the Messages API (you may need to check the relevant model permissions or turn off the permission check to access this API to calculate the request token of a certain Claude model. It is recommended to use the same Key as the request Messages API). Our server will automatically ignore irrelevant content in the Body, so you do not need to specifically remove or modify some additional parameters. You can use it directly without reporting an error. It can be conveniently used to pre-check the number of tokens input by the user to control costs, etc.

This API is free to call, and no billing or other records will be generated when calling this interface.

Official document address: https://docs.anthropic.com/en/api/messages-count-tokens

请求参数

Authorization

在 Header 添加参数

Authorization

，其值为在 Bearer 之后拼接 Token

示例：

Authorization: Bearer ********************

Body 参数application/json

示例

返回响应

🟢200success

application/json

Body

请求示例

Shell

JavaScript

Java

Swift

curl --location --request POST 'https://cn2us02.opapi.win/v1/messages/count_tokens' \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data-raw '{
    "model": "claude-3-opus",
    "stream": false,
    "messages": [
        {
            "role": "user",
            "content": "Say test"
        }
    ],
    "max_tokens": 4096
}'

响应示例

{
    "input_tokens": 9
}

修改于 2025-10-15 08:07:30

Anthropic native Messages API

Introduction to Open OAuth API