Claude-Compatible â€” API Docs

Endpoints under the Claude-compatible surface.

Method	Path	Description
POST	/v1/messages	Create a Claude message through Anthropic Messages.
POST	/v1/messages/count_tokens	Count Claude tokens.

Messages

Messages example

curl https://api.flexkey.ai/v1/messages \
  -H "Authorization: Bearer sk-..." \
  -H "Content-Type: application/json" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-sonnet-4-6",
    "max_tokens": 128,
    "messages": [{ "role": "user", "content": "Reply with ok" }]
  }'

Token counting

curl https://api.flexkey.ai/v1/messages/count_tokens \
  -H "Authorization: Bearer sk-..." \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-6",
    "messages": [{ "role": "user", "content": "How many tokens is this?" }]
  }'

Token counting returns {"input_tokens": 14} and is intended for Claude models before sending a full Messages request.