Count tokens
POST /api/anthropic/v1/messages/count_tokens: the exact prompt size a request would be billed for, without running it. For examples and explanations, see the Messages API guide.
Count tokens
POST /api/anthropic/v1/messages/count_tokens
The exact number of input tokens a message request would use: system prompt, tools and images included. Free of charge. Accepts model, messages, system, tools, tool_choice, thinking and output_config; generation fields such as max_tokens are rejected.
Request
curl https://api.ark-labs.cloud/api/anthropic/v1/messages/count_tokens \
-H "Authorization: Bearer $ARK_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "arklabsai/Qwen3.5-122B-A10B",
"messages": [{"role": "user", "content": "Hello"}]}'Response
{ "input_tokens": 18 }