Chat Completions

Creates a model response for the given chat conversation.

Endpoint

POST /v1/chat/completions

Request Body

Parameter	Type	Required	Description
`model`	string	No	Model ID (defaults to `gemma-4-26b`)
`messages`	array	Yes	Array of message objects
`stream`	boolean	No	Enable SSE streaming (default: `false`)
`temperature`	number	No	Sampling temperature (0-2, default: 1)
`max_tokens`	integer	No	Maximum tokens to generate (1-128000)
`top_p`	number	No	Nucleus sampling (0-1, default: 1)
`frequency_penalty`	number	No	Frequency penalty (-2 to 2)
`presence_penalty`	number	No	Presence penalty (-2 to 2)
`stop`	string/array	No	Stop sequences
`n`	integer	No	Number of completions (1-128)
`tools`	array	No	Function/tool definitions
`tool_choice`	string/object	No	Tool selection strategy

Message Object

Field	Type	Required	Description
`role`	string	Yes	`system`, `user`, `assistant`, or `tool`
`content`	string	Yes	Message content
`tool_call_id`	string	No	Required for `role: "tool"`
`tool_calls`	array	No	Tool calls made by assistant

Example

curl -X POST https://cryptgpt.co/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gemma-4-26b",
    "messages": [
      {"role": "system", "content": "You are a helpful assistant."},
      {"role": "user", "content": "What is the capital of France?"}
    ],
    "temperature": 0.7,
    "max_tokens": 1024
  }'

Response

{
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
  "created": 1718169600,
  "model": "gemma-4-26b",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "The capital of France is Paris."
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 25,
    "completion_tokens": 8,
    "total_tokens": 33
  }
}

Streaming

Set stream: true to receive Server-Sent Events (SSE):

data: {"id":"chatcmpl-abc","object":"chat.completion.chunk","choices":[{"delta":{"role":"assistant"},"finish_reason":null}]}

data: {"id":"chatcmpl-abc","object":"chat.completion.chunk","choices":[{"delta":{"content":"The"},"finish_reason":null}]}

data: {"id":"chatcmpl-abc","object":"chat.completion.chunk","choices":[{"delta":{"content":" capital"},"finish_reason":null}]}

data: {"id":"chatcmpl-abc","object":"chat.completion.chunk","choices":[{"delta":{},"finish_reason":"stop"}]}

data: [DONE]

Function Calling

Pass tools in the request to enable function calling:

{
  "model": "gemma-4-26b",
  "messages": [{"role": "user", "content": "What's the weather in London?"}],
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "get_weather",
        "description": "Get current weather for a location",
        "parameters": {
          "type": "object",
          "properties": {
            "location": {"type": "string", "description": "City name"}
          },
          "required": ["location"]
        }
      }
    }
  ]
}

Error Responses

Status	Type	Description
401	`authentication_error`	Invalid or missing API key
400	`invalid_request_error`	Invalid request parameters
429	`rate_limit_error`	Rate limit exceeded
502	`upstream_error`	Model service unavailable