Count tokens in a message

documented

Count tokens in a message before sending to Claude to estimate costs and rate limits.

POST /v1/messages/count_tokensMessagesno implementation yet0 runs

Input

model*

Claude Model ID

claude-opus-4-1-20250805

system_content*

System Message Content

System prompt

user_content*

User Message Content

User prompt

Calls Anthropic as you (your API key is your account); keychains.dev holds the credentials.