Create Thinking Chat

POST: https://www.kkiai.com/v1/messages

Given a prompt, the model will return one or more predicted completions, and can also return the probability of alternative tokens at each position.

Create a completion for the provided prompt and parameters.

Official documentation: https://docs.anthropic.com/en/docs/build-with-claude/extended-thinking

Request Parameters

Authorization

Add the Authorization parameter to the Header, with its value being the Token concatenated after Bearer.

Example: Authorization: Bearer YOUR_API_KEY

Header Parameters

Parameter Name	Type	Required	Description	Example
Content-Type	string	Required		application/json
Accept	string	Required		application/json
Authorization	string	Required	API key used for authentication.	Bearer YOUR_API_KEY

Body Parameters (application/json)

Parameter Name	Type	Required	Description
model	string	Required	The ID of the model to use. For details on which models can be used with the Chat API, see the model endpoint compatibility table.
system	string	Optional	System prompt used to provide high-level instructions to the model.
messages	array[object]	Required	A list of messages comprising the conversation so far.
└ role	string	Required	The role of the message author, such as user or assistant.
└ content	string	Required	The text content of the message.
temperature	number	Optional	What sampling temperature to use, between 0 and 2. Higher values like 0.8 will make the output more random, while lower values like 0.2 will make it more focused and deterministic. We generally recommend altering this or top_p, but not both.
top_p	number	Optional	An alternative to sampling with temperature, called nucleus sampling, where the model considers the results of the tokens with top_p probability mass. So 0.1 means only the tokens comprising the top 10% probability mass are considered. We generally recommend altering this or temperature, but not both.
n	integer	Optional	Defaults to 1. How many chat completion choices to generate for each input message.
stream	boolean	Optional	Defaults to false. If set, partial message deltas will be sent, like in ChatGPT. Tokens will be sent as data-only server-sent events as they become available, with the stream terminated by a data: [DONE] message.
stop	string	Optional	Defaults to null. Up to 4 sequences where the API will stop generating further tokens.
max_tokens	integer	Optional	Defaults to inf. The maximum number of tokens to generate in the chat completion. The total length of input tokens and generated tokens is limited by the model's context length.
thinking	object	Optional	Enables extended thinking for supported models.
└ type	string	Optional	Set to enabled to enable extended thinking.
└ budget_tokens	integer	Optional	The token budget allocated for extended thinking.
presence_penalty	number	Optional	Defaults to 0. A number between -2.0 and 2.0. Positive values penalize new tokens based on whether they appear in the text so far, increasing the model's likelihood to talk about new topics. See more information about frequency and presence penalties.
frequency_penalty	number	Optional	Defaults to 0. A number between -2.0 and 2.0. Positive values penalize new tokens based on their existing frequency in the text so far, decreasing the model's likelihood to repeat the same line verbatim. See more information about frequency and presence penalties.
logit_bias	object or null	Optional	Modify the likelihood of specified tokens appearing in the completion. Accepts a JSON object that maps tokens to an associated bias value from -100 to 100.
user	string	Optional	A unique identifier representing your end-user, which can help OpenAI monitor and detect abuse. Learn more.
response_format	object	Optional	An object specifying the format that the model must output.
seed	integer	Optional	This feature is in beta. If specified, our system will make a best effort to sample deterministically.
tools	array[object]	Optional	A list of tools the model may call. Currently, only functions are supported as a tool.
tool_choice	string or object	Optional	Controls which function, if any, the model calls.

Request Example

{
  "model": "claude-sonnet-4-20250514",
  "system": "You are a helpful AI assistant named Alex.",
  "messages": [
    {
      "role": "user",
      "content": "Who are you?"
    }
  ],
  "stream": true,
  "max_tokens": 8000,
  "thinking": {
    "type": "enabled",
    "budget_tokens": 1200
  }
}

cURL Example

curl --location --request POST 'https://www.kkiai.com/v1/messages' \
--header 'Accept: application/json' \
--header 'Authorization: Bearer YOUR_API_KEY' \
--header 'Content-Type: application/json' \
--data-raw '{
  "model": "claude-sonnet-4-20250514",
  "system": "You are a helpful AI assistant named Alex.",
  "messages": [
    {
      "role": "user",
      "content": "Who are you?"
    }
  ],
  "stream": true,
  "max_tokens": 8000,
  "thinking": {
    "type": "enabled",
    "budget_tokens": 1200
  }
}'

Response

🟢 200 OK

Response Body

Parameter Name	Type	Required	Description
id	string	Required
object	string	Required
created	integer	Required
choices	array[object]	Required
└ index	integer	Optional
└ message	object	Optional
└ finish_reason	string	Optional
usage	object	Required
└ prompt_tokens	integer	Required
└ completion_tokens	integer	Required
└ total_tokens	integer	Required

Response Example

{
  "id": "chatcmpl-123",
  "object": "chat.completion",
  "created": 1677652288,
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "\n\nHello there, how may I assist you today?"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 9,
    "completion_tokens": 12,
    "total_tokens": 21
  }
}