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Messages API

POST /v1/messages

Send messages to LLM, compatible with Anthropic Claude API format.

Request Format

curl -X POST http://localhost:3456/v1/messages \
-H "x-api-key: your-api-key" \
-H "content-type: application/json" \
-d '{
"model": "claude-3-5-sonnet-20241022",
"max_tokens": 1024,
"messages": [
{
"role": "user",
"content": "Hello, Claude!"
}
]
}'

Request Parameters

ParameterTypeRequiredDescription
modelstringYesModel name (will be routed to actual provider)
messagesarrayYesArray of messages
max_tokensintegerYesMaximum tokens to generate
systemstringNoSystem prompt
toolsarrayNoList of available tools
streambooleanNoWhether to use streaming response (default false)
temperaturenumberNoTemperature parameter (0-1)

Message Object Format

{
"role": "user|assistant",
"content": "string | array"
}

Response Format (Non-streaming)

{
"id": "msg_xxx",
"type": "message",
"role": "assistant",
"content": [
{
"type": "text",
"text": "Hello! How can I help you today?"
}
],
"model": "claude-3-5-sonnet-20241022",
"stop_reason": "end_turn",
"usage": {
"input_tokens": 10,
"output_tokens": 20
}
}

Streaming Response

Set stream: true to enable streaming response:

{
"model": "claude-3-5-sonnet-20241022",
"max_tokens": 1024,
"messages": [...],
"stream": true
}

Streaming response event types:

  • message_start - Message start
  • content_block_start - Content block start
  • content_block_delta - Content increment
  • content_block_stop - Content block end
  • message_delta - Message metadata (usage)
  • message_stop - Message end

Tool Use

Supports function calling (Tool Use):

{
"model": "claude-3-5-sonnet-20241022",
"max_tokens": 1024,
"messages": [
{
"role": "user",
"content": "What's the weather like?"
}
],
"tools": [
{
"name": "get_weather",
"description": "Get the current weather",
"input_schema": {
"type": "object",
"properties": {
"location": {
"type": "string",
"description": "City name"
}
},
"required": ["location"]
}
}
]
}

Multimodal Support

Supports image input:

{
"role": "user",
"content": [
{
"type": "image",
"source": {
"type": "base64",
"media_type": "image/png",
"data": "iVBORw0KGgo..."
}
},
{
"type": "text",
"text": "Describe this image"
}
]
}

POST /v1/messages/count_tokens

Count tokens in messages.

Request Format

curl -X POST http://localhost:3456/v1/messages/count_tokens \
-H "x-api-key: your-api-key" \
-H "content-type: application/json" \
-d '{
"model": "claude-3-5-sonnet-20241022",
"messages": [
{
"role": "user",
"content": "Hello!"
}
],
"tools": [],
"system": "You are a helpful assistant."
}'

Request Parameters

ParameterTypeRequiredDescription
modelstringYesModel name
messagesarrayYesArray of messages
toolsarrayNoList of tools
systemstringNoSystem prompt

Response Format

{
"input_tokens": 42
}

Error Responses

400 Bad Request

{
"error": {
"type": "invalid_request_error",
"message": "messages is required"
}
}

401 Unauthorized

{
"error": {
"type": "authentication_error",
"message": "Invalid API key"
}
}

500 Internal Server Error

{
"error": {
"type": "api_error",
"message": "Failed to connect to provider"
}
}