Messages (Anthropic format)

POST https://api.vikey.ai/v1/messages

The request and response follow the Anthropic Messages API. Claude Code and the Anthropic SDK use this endpoint. Every text model on Vikey can be called through it, including GPT and DeepSeek.

Example

curl https://api.vikey.ai/v1/messages \
  -H "x-api-key: YOUR_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{
    "model": "anthropic/claude-sonnet-5.5",
    "max_tokens": 1024,
    "system": "Answer briefly.",
    "messages": [{"role": "user", "content": "What is the difference between let and const in JavaScript?"}]
  }'

Authorization: Bearer YOUR_API_KEY is also accepted instead of x-api-key.

Common parameters

Parameter	Notes
model	Required. A Vikey model id.
max_tokens	Required in the Anthropic format. Also used for the balance check.
messages	Required. user and assistant messages with text or content blocks (text, images, tool_use, tool_result).
system	System prompt, as text or an array of blocks.
stream	true for an Anthropic-format event stream.
tools, tool_choice	Tool use in the Anthropic format.
cache_control	Cache markers on content blocks are passed to models that support them.

Response

{
  "id": "msg_...",
  "type": "message",
  "role": "assistant",
  "model": "anthropic/claude-sonnet-5.5",
  "content": [{"type": "text", "text": "let can be reassigned, const cannot..."}],
  "stop_reason": "end_turn",
  "usage": {"input_tokens": 32, "output_tokens": 58}
}

Errors use the Anthropic shape: {"type": "error", "error": {"type": "...", "message": "..."}}. See Errors.