Count Tokens (Claude)

curl --request POST \
  --url https://api.leapx-hub.com/v1/messages/count_tokens \
  --header 'Authorization: <authorization>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "<string>",
  "messages": [
    {}
  ],
  "system": {},
  "tools": [
    {}
  ]
}
'

import requests

url = "https://api.leapx-hub.com/v1/messages/count_tokens"

payload = {
    "model": "<string>",
    "messages": [{}],
    "system": {},
    "tools": [{}]
}
headers = {
    "Authorization": "<authorization>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: '<authorization>', 'Content-Type': 'application/json'},
  body: JSON.stringify({model: '<string>', messages: [{}], system: {}, tools: [{}]})
};

fetch('https://api.leapx-hub.com/v1/messages/count_tokens', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.leapx-hub.com/v1/messages/count_tokens",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'model' => '<string>',
    'messages' => [
        [
                
        ]
    ],
    'system' => [
        
    ],
    'tools' => [
        [
                
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <authorization>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.leapx-hub.com/v1/messages/count_tokens"

	payload := strings.NewReader("{\n  \"model\": \"<string>\",\n  \"messages\": [\n    {}\n  ],\n  \"system\": {},\n  \"tools\": [\n    {}\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "<authorization>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.leapx-hub.com/v1/messages/count_tokens")
  .header("Authorization", "<authorization>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"<string>\",\n  \"messages\": [\n    {}\n  ],\n  \"system\": {},\n  \"tools\": [\n    {}\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.leapx-hub.com/v1/messages/count_tokens")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<authorization>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"<string>\",\n  \"messages\": [\n    {}\n  ],\n  \"system\": {},\n  \"tools\": [\n    {}\n  ]\n}"

response = http.request(request)
puts response.read_body

{
  "input_tokens": 14
}

POST

messages

count_tokens

Count Tokens (Claude)

curl --request POST \
  --url https://api.leapx-hub.com/v1/messages/count_tokens \
  --header 'Authorization: <authorization>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "<string>",
  "messages": [
    {}
  ],
  "system": {},
  "tools": [
    {}
  ]
}
'

import requests

url = "https://api.leapx-hub.com/v1/messages/count_tokens"

payload = {
    "model": "<string>",
    "messages": [{}],
    "system": {},
    "tools": [{}]
}
headers = {
    "Authorization": "<authorization>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: '<authorization>', 'Content-Type': 'application/json'},
  body: JSON.stringify({model: '<string>', messages: [{}], system: {}, tools: [{}]})
};

fetch('https://api.leapx-hub.com/v1/messages/count_tokens', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.leapx-hub.com/v1/messages/count_tokens",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'model' => '<string>',
    'messages' => [
        [
                
        ]
    ],
    'system' => [
        
    ],
    'tools' => [
        [
                
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <authorization>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.leapx-hub.com/v1/messages/count_tokens"

	payload := strings.NewReader("{\n  \"model\": \"<string>\",\n  \"messages\": [\n    {}\n  ],\n  \"system\": {},\n  \"tools\": [\n    {}\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "<authorization>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.leapx-hub.com/v1/messages/count_tokens")
  .header("Authorization", "<authorization>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"<string>\",\n  \"messages\": [\n    {}\n  ],\n  \"system\": {},\n  \"tools\": [\n    {}\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.leapx-hub.com/v1/messages/count_tokens")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<authorization>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"<string>\",\n  \"messages\": [\n    {}\n  ],\n  \"system\": {},\n  \"tools\": [\n    {}\n  ]\n}"

response = http.request(request)
puts response.read_body

{
  "input_tokens": 14
}

Introduction

Calculate the token count of Claude messages to estimate costs before sending requests. This endpoint does not consume quota and only performs local calculations.

Authentication

string

required

Bearer Token, e.g., Bearer sk-xxxxxxxxxx

Request Parameters

string

required

Claude model identifier. Supported models include:

claude-opus-4-5-20251101 (Recommended replacement for claude-3-opus)
claude-haiku-4-5-20251001
claude-sonnet-4-5-20250929
claude-sonnet-4-20250514
Other Claude series models

array

required

List of conversation messages, each containing role (user/assistant) and content. content can be a string or an array of media content.Supported content types:

Plain text messages
Multimodal messages (including images)
Tool call results

string|array

System prompt (optional), can be a string or an array of media content. Used to set the model’s behavior and role.

array

Tool definitions list (optional), used to calculate tokens related to tool calls.

Response Parameters

number

Total token count of input messages, including:

System prompt tokens
All messages tokens
Tools definition tokens (if any)

Basic Examples

Simple Text Message
With System Prompt
Multi-turn Conversation
Python Example

curl -X POST "https://api.leapx-hub.com/v1/messages/count_tokens" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -d '{
    "model": "claude-sonnet-4-5-20250929",
    "messages": [
      {
        "role": "user",
        "content": "Hello, how are you?"
      }
    ]
  }'

curl -X POST "https://api.leapx-hub.com/v1/messages/count_tokens" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -d '{
    "model": "claude-sonnet-4-5-20250929",
    "system": "You are a helpful AI assistant.",
    "messages": [
      {
        "role": "user",
        "content": "What is artificial intelligence?"
      }
    ]
  }'

curl -X POST "https://api.leapx-hub.com/v1/messages/count_tokens" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -d '{
    "model": "claude-sonnet-4-5-20250929",
    "messages": [
      {
        "role": "user",
        "content": "Hello"
      },
      {
        "role": "assistant",
        "content": "Hi! How can I help you today?"
      },
      {
        "role": "user",
        "content": "Tell me about the history of AI"
      }
    ]
  }'

from anthropic import Anthropic

client = Anthropic(
    api_key="sk-xxxxxxxxxx",
    base_url="https://api.leapx-hub.com"
)

# Count tokens
response = client.messages.count_tokens(
    model="claude-sonnet-4-5-20250929",
    system="You are a helpful assistant.",
    messages=[
        {"role": "user", "content": "Hello, Claude!"}
    ]
)

print(f"Input tokens: {response.input_tokens}")

{
  "input_tokens": 14
}

Advanced Use Cases

With Tool Definitions

curl -X POST "https://api.leapx-hub.com/v1/messages/count_tokens" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -d '{
    "model": "claude-sonnet-4-5-20250929",
    "messages": [
      {
        "role": "user",
        "content": "What is the weather in San Francisco?"
      }
    ],
    "tools": [
      {
        "name": "get_weather",
        "description": "Get the current weather in a given location",
        "input_schema": {
          "type": "object",
          "properties": {
            "location": {
              "type": "string",
              "description": "The city and state, e.g. San Francisco, CA"
            }
          },
          "required": ["location"]
        }
      }
    ]
  }'

Multimodal Content

curl -X POST "https://api.leapx-hub.com/v1/messages/count_tokens" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sk-xxxxxxxxxx" \
  -d '{
    "model": "claude-sonnet-4-5-20250929",
    "messages": [
      {
        "role": "user",
        "content": [
          {
            "type": "text",
            "text": "What is in this image?"
          },
          {
            "type": "image",
            "source": {
              "type": "url",
              "url": "https://example.com/image.jpg"
            }
          }
        ]
      }
    ]
  }'

Use Cases

1. Cost Estimation

Calculate token counts before sending bulk requests to estimate costs:

# Batch cost calculation
messages_batch = [...]  # Batch messages
total_tokens = 0

for messages in messages_batch:
    response = client.messages.count_tokens(
        model="claude-sonnet-4-5-20250929",
        messages=messages
    )
    total_tokens += response.input_tokens

# Calculate total cost based on pricing
cost = total_tokens * price_per_token
print(f"Estimated cost: ${cost:.4f}")

2. Context Window Management

Check if messages exceed the model’s context window limit:

MAX_CONTEXT_WINDOW = 200000  # Claude Sonnet 4.5's context window

response = client.messages.count_tokens(
    model="claude-sonnet-4-5-20250929",
    messages=long_conversation
)

if response.input_tokens > MAX_CONTEXT_WINDOW:
    print(f"Warning: Message tokens ({response.input_tokens}) exceed context window limit")
    # Perform message truncation or summarization

3. Prompt Optimization

Compare token consumption of different prompts:

prompts = [
    "Concise prompt...",
    "Detailed prompt...",
    "Very detailed prompt..."
]

for prompt in prompts:
    response = client.messages.count_tokens(
        model="claude-sonnet-4-5-20250929",
        system=prompt,
        messages=[{"role": "user", "content": "test"}]
    )
    print(f"{len(prompt)} chars -> {response.input_tokens} tokens")

Important Notes

Image tokens use a fixed estimate (~1000 tokens), actual count may vary based on resolution
Does not include output-related parameters like max_tokens, only counts input tokens
This endpoint does not make actual AI requests and does not consume quota

Error Handling

Missing Required Parameters

{
  "type": "error",
  "error": {
    "type": "invalid_request_error",
    "message": "Key: 'ClaudeCountTokensRequest.Model' Error:Field validation for 'Model' failed on the 'required' tag"
  }
}

Invalid API Key

{
  "error": {
    "message": "Invalid token",
    "type": "invalid_request_error"
  }
}

Create Message Request (Claude) - Send actual Claude requests
Model List - View supported Claude models
Pricing - Learn about token billing standards

API documentation

Text Series

Text Embedding Series

Image Series

Video Series

Realtime Voice

Count Tokens (Claude)

Introduction

Authentication

Request Parameters

Response Parameters

Basic Examples

Advanced Use Cases

With Tool Definitions

Multimodal Content

Use Cases

1. Cost Estimation

2. Context Window Management

3. Prompt Optimization

Important Notes

Error Handling

Missing Required Parameters

Invalid API Key

​Introduction

​Authentication

​Request Parameters

​Response Parameters

​Basic Examples

​Advanced Use Cases

​With Tool Definitions

​Multimodal Content

​Use Cases

​1. Cost Estimation

​2. Context Window Management

​3. Prompt Optimization

​Important Notes

​Error Handling

​Missing Required Parameters

​Invalid API Key

​Related Resources

Introduction

Authentication

Request Parameters

Response Parameters

Basic Examples

Advanced Use Cases

With Tool Definitions

Multimodal Content

Use Cases

1. Cost Estimation

2. Context Window Management

3. Prompt Optimization

Important Notes

Error Handling

Missing Required Parameters

Invalid API Key

Related Resources