Messages

/v1/messages is the Anthropic Messages compatible entrypoint for Claude Code and Anthropic protocol clients. The server selects the upstream or conversion path from the API key group platform, model mapping, and account capabilities.

Interface

Item	Value
Method	POST
Path	/v1/messages
Content-Type	application/json
Authentication	Authorization: Bearer YOUR_API_KEY

Request Parameters

Parameter	Type	Required	Description
model	string	Yes	Requested model. The gateway applies group model mapping and platform routing.
messages	array	Yes	Anthropic Messages style message array.
max_tokens	integer	Usually	Maximum output tokens.
system	string or array	No	System prompt.
stream	boolean	No	Whether to stream the response.
thinking	object	No	Reasoning configuration, applied by model and platform capability.
metadata.user_id	string	No	Can be used for sticky sessions and request tracking.

Request Example

curl https://llmapi.site/v1/messages \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "claude-sonnet-4-5",
    "max_tokens": 512,
    "messages": [
      { "role": "user", "content": "Summarize this request." }
    ]
  }'

The response is returned as an Anthropic Messages compatible payload according to the upstream and conversion path.

Token Count

/v1/messages/count_tokens provides Anthropic token counting. It checks subscription and balance, but does not acquire concurrency or record usage.

Item	Value
Method	POST
Path	/v1/messages/count_tokens
Content-Type	application/json
Restriction	Not supported for OpenAI platform groups

Request example:

curl https://llmapi.site/v1/messages/count_tokens \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "claude-sonnet-4-5",
    "messages": [
      { "role": "user", "content": "Hello" }
    ]
  }'

OpenAI group response example:

{
  "type": "error",
  "error": {
    "type": "not_found_error",
    "message": "Token counting is not supported for this platform"
  }
}