GPT Chat Completions (All Models, Full Parameters)

curl --request POST \
  --url https://direct.evolink.ai/v1/chat/completions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "gpt-5.6-sol",
  "messages": [
    {
      "role": "system",
      "content": "You are a concise assistant."
    },
    {
      "role": "user",
      "content": "Explain quantum entanglement in one sentence."
    }
  ],
  "stream": false,
  "max_completion_tokens": 2048,
  "reasoning_effort": "medium",
  "verbosity": "low",
  "temperature": 0.7,
  "top_p": 0.9,
  "frequency_penalty": 0.5,
  "presence_penalty": 0.5,
  "logprobs": true,
  "top_logprobs": 2,
  "n": 1,
  "seed": 42,
  "response_format": {
    "type": "json_schema",
    "json_schema": {}
  },
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "get_weather",
        "description": "Get the weather for a specified city",
        "parameters": {}
      }
    }
  ],
  "parallel_tool_calls": true,
  "prompt_cache_key": "app-chat-v1",
  "user": "user-1024"
}
'

import requests

url = "https://direct.evolink.ai/v1/chat/completions"

payload = {
    "model": "gpt-5.6-sol",
    "messages": [
        {
            "role": "system",
            "content": "You are a concise assistant."
        },
        {
            "role": "user",
            "content": "Explain quantum entanglement in one sentence."
        }
    ],
    "stream": False,
    "max_completion_tokens": 2048,
    "reasoning_effort": "medium",
    "verbosity": "low",
    "temperature": 0.7,
    "top_p": 0.9,
    "frequency_penalty": 0.5,
    "presence_penalty": 0.5,
    "logprobs": True,
    "top_logprobs": 2,
    "n": 1,
    "seed": 42,
    "response_format": {
        "type": "json_schema",
        "json_schema": {}
    },
    "tools": [
        {
            "type": "function",
            "function": {
                "name": "get_weather",
                "description": "Get the weather for a specified city",
                "parameters": {}
            }
        }
    ],
    "parallel_tool_calls": True,
    "prompt_cache_key": "app-chat-v1",
    "user": "user-1024"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    model: 'gpt-5.6-sol',
    messages: [
      {role: 'system', content: 'You are a concise assistant.'},
      {role: 'user', content: 'Explain quantum entanglement in one sentence.'}
    ],
    stream: false,
    max_completion_tokens: 2048,
    reasoning_effort: 'medium',
    verbosity: 'low',
    temperature: 0.7,
    top_p: 0.9,
    frequency_penalty: 0.5,
    presence_penalty: 0.5,
    logprobs: true,
    top_logprobs: 2,
    n: 1,
    seed: 42,
    response_format: {type: 'json_schema', json_schema: {}},
    tools: [
      {
        type: 'function',
        function: {
          name: 'get_weather',
          description: 'Get the weather for a specified city',
          parameters: {}
        }
      }
    ],
    parallel_tool_calls: true,
    prompt_cache_key: 'app-chat-v1',
    user: 'user-1024'
  })
};

fetch('https://direct.evolink.ai/v1/chat/completions', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://direct.evolink.ai/v1/chat/completions",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'model' => 'gpt-5.6-sol',
    'messages' => [
        [
                'role' => 'system',
                'content' => 'You are a concise assistant.'
        ],
        [
                'role' => 'user',
                'content' => 'Explain quantum entanglement in one sentence.'
        ]
    ],
    'stream' => false,
    'max_completion_tokens' => 2048,
    'reasoning_effort' => 'medium',
    'verbosity' => 'low',
    'temperature' => 0.7,
    'top_p' => 0.9,
    'frequency_penalty' => 0.5,
    'presence_penalty' => 0.5,
    'logprobs' => true,
    'top_logprobs' => 2,
    'n' => 1,
    'seed' => 42,
    'response_format' => [
        'type' => 'json_schema',
        'json_schema' => [
                
        ]
    ],
    'tools' => [
        [
                'type' => 'function',
                'function' => [
                                'name' => 'get_weather',
                                'description' => 'Get the weather for a specified city',
                                'parameters' => [
                                                                
                                ]
                ]
        ]
    ],
    'parallel_tool_calls' => true,
    'prompt_cache_key' => 'app-chat-v1',
    'user' => 'user-1024'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://direct.evolink.ai/v1/chat/completions"

	payload := strings.NewReader("{\n  \"model\": \"gpt-5.6-sol\",\n  \"messages\": [\n    {\n      \"role\": \"system\",\n      \"content\": \"You are a concise assistant.\"\n    },\n    {\n      \"role\": \"user\",\n      \"content\": \"Explain quantum entanglement in one sentence.\"\n    }\n  ],\n  \"stream\": false,\n  \"max_completion_tokens\": 2048,\n  \"reasoning_effort\": \"medium\",\n  \"verbosity\": \"low\",\n  \"temperature\": 0.7,\n  \"top_p\": 0.9,\n  \"frequency_penalty\": 0.5,\n  \"presence_penalty\": 0.5,\n  \"logprobs\": true,\n  \"top_logprobs\": 2,\n  \"n\": 1,\n  \"seed\": 42,\n  \"response_format\": {\n    \"type\": \"json_schema\",\n    \"json_schema\": {}\n  },\n  \"tools\": [\n    {\n      \"type\": \"function\",\n      \"function\": {\n        \"name\": \"get_weather\",\n        \"description\": \"Get the weather for a specified city\",\n        \"parameters\": {}\n      }\n    }\n  ],\n  \"parallel_tool_calls\": true,\n  \"prompt_cache_key\": \"app-chat-v1\",\n  \"user\": \"user-1024\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://direct.evolink.ai/v1/chat/completions")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"gpt-5.6-sol\",\n  \"messages\": [\n    {\n      \"role\": \"system\",\n      \"content\": \"You are a concise assistant.\"\n    },\n    {\n      \"role\": \"user\",\n      \"content\": \"Explain quantum entanglement in one sentence.\"\n    }\n  ],\n  \"stream\": false,\n  \"max_completion_tokens\": 2048,\n  \"reasoning_effort\": \"medium\",\n  \"verbosity\": \"low\",\n  \"temperature\": 0.7,\n  \"top_p\": 0.9,\n  \"frequency_penalty\": 0.5,\n  \"presence_penalty\": 0.5,\n  \"logprobs\": true,\n  \"top_logprobs\": 2,\n  \"n\": 1,\n  \"seed\": 42,\n  \"response_format\": {\n    \"type\": \"json_schema\",\n    \"json_schema\": {}\n  },\n  \"tools\": [\n    {\n      \"type\": \"function\",\n      \"function\": {\n        \"name\": \"get_weather\",\n        \"description\": \"Get the weather for a specified city\",\n        \"parameters\": {}\n      }\n    }\n  ],\n  \"parallel_tool_calls\": true,\n  \"prompt_cache_key\": \"app-chat-v1\",\n  \"user\": \"user-1024\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://direct.evolink.ai/v1/chat/completions")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"gpt-5.6-sol\",\n  \"messages\": [\n    {\n      \"role\": \"system\",\n      \"content\": \"You are a concise assistant.\"\n    },\n    {\n      \"role\": \"user\",\n      \"content\": \"Explain quantum entanglement in one sentence.\"\n    }\n  ],\n  \"stream\": false,\n  \"max_completion_tokens\": 2048,\n  \"reasoning_effort\": \"medium\",\n  \"verbosity\": \"low\",\n  \"temperature\": 0.7,\n  \"top_p\": 0.9,\n  \"frequency_penalty\": 0.5,\n  \"presence_penalty\": 0.5,\n  \"logprobs\": true,\n  \"top_logprobs\": 2,\n  \"n\": 1,\n  \"seed\": 42,\n  \"response_format\": {\n    \"type\": \"json_schema\",\n    \"json_schema\": {}\n  },\n  \"tools\": [\n    {\n      \"type\": \"function\",\n      \"function\": {\n        \"name\": \"get_weather\",\n        \"description\": \"Get the weather for a specified city\",\n        \"parameters\": {}\n      }\n    }\n  ],\n  \"parallel_tool_calls\": true,\n  \"prompt_cache_key\": \"app-chat-v1\",\n  \"user\": \"user-1024\"\n}"

response = http.request(request)
puts response.read_body

{
  "id": "chatcmpl-CvJ2p8mQxK7nR4wS",
  "object": "chat.completion",
  "created": 1786705221,
  "model": "gpt-5.6-sol",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Quantum entanglement means the states of two particles are correlated, so measuring one instantly determines the state of the other.",
        "tool_calls": [
          {}
        ]
      },
      "logprobs": {},
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 18,
    "completion_tokens": 42,
    "total_tokens": 60,
    "prompt_tokens_details": {
      "cached_tokens": 0
    },
    "completion_tokens_details": {
      "reasoning_tokens": 16
    }
  }
}

{
  "error": {
    "code": 400,
    "message": "Unsupported parameter: 'stop' is not supported with this model.",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": 401,
    "message": "Invalid or expired token",
    "type": "authentication_error"
  }
}

{
  "error": {
    "code": 402,
    "message": "Insufficient quota",
    "type": "insufficient_quota_error",
    "fallback_suggestion": "https://evolink.ai/dashboard/billing"
  }
}

{
  "error": {
    "code": 429,
    "message": "Rate limit exceeded",
    "type": "rate_limit_error",
    "fallback_suggestion": "retry after 60 seconds"
  }
}

{
  "error": {
    "code": 500,
    "message": "Internal server error",
    "type": "internal_server_error",
    "fallback_suggestion": "try again later"
  }
}

{
  "error": {
    "code": 503,
    "message": "Service temporarily unavailable",
    "type": "service_unavailable_error",
    "fallback_suggestion": "retry after 30 seconds"
  }
}

Chat Completions API

GPT All-Model API - Chat Completions Reference

OpenAI-compatible Chat Completions API for GPT series text models; select the specific model via model (see the comparison table on the model parameter for all allowed values)
The whole series consists of reasoning models, with reasoning depth controlled by reasoning_effort; reasoning tokens are billed as output tokens
Prompt caching applies automatically: cached input tokens are billed at the lower cached rate
Supports both synchronous and streaming (SSE) modes
Supports mixed text and image input, as well as function tool calls
Server-side tools (web search, code execution, file search, MCP) are provided only on the Responses API
Note Model support varies for the sampling parameters (temperature, top_p, logprobs, and so on); see the per-parameter notes below

POST

chat

completions

GPT Chat Completions (All Models, Full Parameters)

curl --request POST \
  --url https://direct.evolink.ai/v1/chat/completions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "gpt-5.6-sol",
  "messages": [
    {
      "role": "system",
      "content": "You are a concise assistant."
    },
    {
      "role": "user",
      "content": "Explain quantum entanglement in one sentence."
    }
  ],
  "stream": false,
  "max_completion_tokens": 2048,
  "reasoning_effort": "medium",
  "verbosity": "low",
  "temperature": 0.7,
  "top_p": 0.9,
  "frequency_penalty": 0.5,
  "presence_penalty": 0.5,
  "logprobs": true,
  "top_logprobs": 2,
  "n": 1,
  "seed": 42,
  "response_format": {
    "type": "json_schema",
    "json_schema": {}
  },
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "get_weather",
        "description": "Get the weather for a specified city",
        "parameters": {}
      }
    }
  ],
  "parallel_tool_calls": true,
  "prompt_cache_key": "app-chat-v1",
  "user": "user-1024"
}
'

import requests

url = "https://direct.evolink.ai/v1/chat/completions"

payload = {
    "model": "gpt-5.6-sol",
    "messages": [
        {
            "role": "system",
            "content": "You are a concise assistant."
        },
        {
            "role": "user",
            "content": "Explain quantum entanglement in one sentence."
        }
    ],
    "stream": False,
    "max_completion_tokens": 2048,
    "reasoning_effort": "medium",
    "verbosity": "low",
    "temperature": 0.7,
    "top_p": 0.9,
    "frequency_penalty": 0.5,
    "presence_penalty": 0.5,
    "logprobs": True,
    "top_logprobs": 2,
    "n": 1,
    "seed": 42,
    "response_format": {
        "type": "json_schema",
        "json_schema": {}
    },
    "tools": [
        {
            "type": "function",
            "function": {
                "name": "get_weather",
                "description": "Get the weather for a specified city",
                "parameters": {}
            }
        }
    ],
    "parallel_tool_calls": True,
    "prompt_cache_key": "app-chat-v1",
    "user": "user-1024"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    model: 'gpt-5.6-sol',
    messages: [
      {role: 'system', content: 'You are a concise assistant.'},
      {role: 'user', content: 'Explain quantum entanglement in one sentence.'}
    ],
    stream: false,
    max_completion_tokens: 2048,
    reasoning_effort: 'medium',
    verbosity: 'low',
    temperature: 0.7,
    top_p: 0.9,
    frequency_penalty: 0.5,
    presence_penalty: 0.5,
    logprobs: true,
    top_logprobs: 2,
    n: 1,
    seed: 42,
    response_format: {type: 'json_schema', json_schema: {}},
    tools: [
      {
        type: 'function',
        function: {
          name: 'get_weather',
          description: 'Get the weather for a specified city',
          parameters: {}
        }
      }
    ],
    parallel_tool_calls: true,
    prompt_cache_key: 'app-chat-v1',
    user: 'user-1024'
  })
};

fetch('https://direct.evolink.ai/v1/chat/completions', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://direct.evolink.ai/v1/chat/completions",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'model' => 'gpt-5.6-sol',
    'messages' => [
        [
                'role' => 'system',
                'content' => 'You are a concise assistant.'
        ],
        [
                'role' => 'user',
                'content' => 'Explain quantum entanglement in one sentence.'
        ]
    ],
    'stream' => false,
    'max_completion_tokens' => 2048,
    'reasoning_effort' => 'medium',
    'verbosity' => 'low',
    'temperature' => 0.7,
    'top_p' => 0.9,
    'frequency_penalty' => 0.5,
    'presence_penalty' => 0.5,
    'logprobs' => true,
    'top_logprobs' => 2,
    'n' => 1,
    'seed' => 42,
    'response_format' => [
        'type' => 'json_schema',
        'json_schema' => [
                
        ]
    ],
    'tools' => [
        [
                'type' => 'function',
                'function' => [
                                'name' => 'get_weather',
                                'description' => 'Get the weather for a specified city',
                                'parameters' => [
                                                                
                                ]
                ]
        ]
    ],
    'parallel_tool_calls' => true,
    'prompt_cache_key' => 'app-chat-v1',
    'user' => 'user-1024'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://direct.evolink.ai/v1/chat/completions"

	payload := strings.NewReader("{\n  \"model\": \"gpt-5.6-sol\",\n  \"messages\": [\n    {\n      \"role\": \"system\",\n      \"content\": \"You are a concise assistant.\"\n    },\n    {\n      \"role\": \"user\",\n      \"content\": \"Explain quantum entanglement in one sentence.\"\n    }\n  ],\n  \"stream\": false,\n  \"max_completion_tokens\": 2048,\n  \"reasoning_effort\": \"medium\",\n  \"verbosity\": \"low\",\n  \"temperature\": 0.7,\n  \"top_p\": 0.9,\n  \"frequency_penalty\": 0.5,\n  \"presence_penalty\": 0.5,\n  \"logprobs\": true,\n  \"top_logprobs\": 2,\n  \"n\": 1,\n  \"seed\": 42,\n  \"response_format\": {\n    \"type\": \"json_schema\",\n    \"json_schema\": {}\n  },\n  \"tools\": [\n    {\n      \"type\": \"function\",\n      \"function\": {\n        \"name\": \"get_weather\",\n        \"description\": \"Get the weather for a specified city\",\n        \"parameters\": {}\n      }\n    }\n  ],\n  \"parallel_tool_calls\": true,\n  \"prompt_cache_key\": \"app-chat-v1\",\n  \"user\": \"user-1024\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://direct.evolink.ai/v1/chat/completions")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"gpt-5.6-sol\",\n  \"messages\": [\n    {\n      \"role\": \"system\",\n      \"content\": \"You are a concise assistant.\"\n    },\n    {\n      \"role\": \"user\",\n      \"content\": \"Explain quantum entanglement in one sentence.\"\n    }\n  ],\n  \"stream\": false,\n  \"max_completion_tokens\": 2048,\n  \"reasoning_effort\": \"medium\",\n  \"verbosity\": \"low\",\n  \"temperature\": 0.7,\n  \"top_p\": 0.9,\n  \"frequency_penalty\": 0.5,\n  \"presence_penalty\": 0.5,\n  \"logprobs\": true,\n  \"top_logprobs\": 2,\n  \"n\": 1,\n  \"seed\": 42,\n  \"response_format\": {\n    \"type\": \"json_schema\",\n    \"json_schema\": {}\n  },\n  \"tools\": [\n    {\n      \"type\": \"function\",\n      \"function\": {\n        \"name\": \"get_weather\",\n        \"description\": \"Get the weather for a specified city\",\n        \"parameters\": {}\n      }\n    }\n  ],\n  \"parallel_tool_calls\": true,\n  \"prompt_cache_key\": \"app-chat-v1\",\n  \"user\": \"user-1024\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://direct.evolink.ai/v1/chat/completions")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"gpt-5.6-sol\",\n  \"messages\": [\n    {\n      \"role\": \"system\",\n      \"content\": \"You are a concise assistant.\"\n    },\n    {\n      \"role\": \"user\",\n      \"content\": \"Explain quantum entanglement in one sentence.\"\n    }\n  ],\n  \"stream\": false,\n  \"max_completion_tokens\": 2048,\n  \"reasoning_effort\": \"medium\",\n  \"verbosity\": \"low\",\n  \"temperature\": 0.7,\n  \"top_p\": 0.9,\n  \"frequency_penalty\": 0.5,\n  \"presence_penalty\": 0.5,\n  \"logprobs\": true,\n  \"top_logprobs\": 2,\n  \"n\": 1,\n  \"seed\": 42,\n  \"response_format\": {\n    \"type\": \"json_schema\",\n    \"json_schema\": {}\n  },\n  \"tools\": [\n    {\n      \"type\": \"function\",\n      \"function\": {\n        \"name\": \"get_weather\",\n        \"description\": \"Get the weather for a specified city\",\n        \"parameters\": {}\n      }\n    }\n  ],\n  \"parallel_tool_calls\": true,\n  \"prompt_cache_key\": \"app-chat-v1\",\n  \"user\": \"user-1024\"\n}"

response = http.request(request)
puts response.read_body

{
  "id": "chatcmpl-CvJ2p8mQxK7nR4wS",
  "object": "chat.completion",
  "created": 1786705221,
  "model": "gpt-5.6-sol",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Quantum entanglement means the states of two particles are correlated, so measuring one instantly determines the state of the other.",
        "tool_calls": [
          {}
        ]
      },
      "logprobs": {},
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 18,
    "completion_tokens": 42,
    "total_tokens": 60,
    "prompt_tokens_details": {
      "cached_tokens": 0
    },
    "completion_tokens_details": {
      "reasoning_tokens": 16
    }
  }
}

{
  "error": {
    "code": 400,
    "message": "Unsupported parameter: 'stop' is not supported with this model.",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": 401,
    "message": "Invalid or expired token",
    "type": "authentication_error"
  }
}

{
  "error": {
    "code": 402,
    "message": "Insufficient quota",
    "type": "insufficient_quota_error",
    "fallback_suggestion": "https://evolink.ai/dashboard/billing"
  }
}

{
  "error": {
    "code": 429,
    "message": "Rate limit exceeded",
    "type": "rate_limit_error",
    "fallback_suggestion": "retry after 60 seconds"
  }
}

{
  "error": {
    "code": 500,
    "message": "Internal server error",
    "type": "internal_server_error",
    "fallback_suggestion": "try again later"
  }
}

{
  "error": {
    "code": 503,
    "message": "Service temporarily unavailable",
    "type": "service_unavailable_error",
    "fallback_suggestion": "retry after 30 seconds"
  }
}

BaseURL: The default BaseURL is https://direct.evolink.ai, which has better support for text models and long-lived connections. https://api.evolink.ai is the primary endpoint for multimodal services and serves as a fallback address for text models.

Server-side tools (web search, code execution, file search, MCP) are only available on the Responses API. The Chat Completions endpoint supports regular function tool calling only.

Note The whole series consists of reasoning models. stop (stop sequences) and web_search_options are not supported on any model and return 400 if passed; logit_bias does not apply to this model series.Model support varies for temperature, top_p, frequency_penalty, presence_penalty, logprobs and verbosity — refer to the notes on each parameter above.

Authorizations

Authorization

string

header

required

##All APIs require Bearer Token authentication##

Get API Key:

Visit API Key Management Page to get your API Key

Add to request header:

Authorization: Bearer YOUR_API_KEY

Body

application/json

model

enum<string>

required

Model to call:

Model ID	Context window	Positioning
`gpt-5.6-sol`	1,050,000	GPT-5.6 family, frontier reasoning
`gpt-5.6-terra`	1,050,000	GPT-5.6 family, balanced production
`gpt-5.6-luna`	1,050,000	GPT-5.6 family, high throughput and cost control
`gpt-5.5`	400,000	General-purpose reasoning model
`gpt-5.4`	128,000	General-purpose reasoning model
`gpt-5.2`	400,000	General-purpose reasoning model
`gpt-5.1`	400,000	General-purpose reasoning model

Available options:

gpt-5.6-sol,

gpt-5.6-terra,

gpt-5.6-luna,

gpt-5.5,

gpt-5.4,

gpt-5.2,

gpt-5.1

Example:

"gpt-5.6-sol"

messages

object[]

required

List of chat messages, supporting multi-turn context and multimodal input.

role can be system / developer / user / assistant / tool.

content can be a string or an array of content blocks. Two block types are supported: text (text) and image_url (image):

"content": [
  { "type": "text", "text": "What is in this image?" },
  {
    "type": "image_url",
    "image_url": { "url": "https://example.com/photo.png", "detail": "auto" }
  }
]

Image

Pass the public URL of the image in image_url.url
image_url can also be written directly as a string, equivalent to { "url": "..." }
detail controls image analysis fidelity: auto (default) / low / high / original
The image must be downloadable, otherwise 400 is returned

Note The block types on this API differ from those on the Responses API (which uses input_text / input_image). They cannot be mixed; using the wrong ones returns 400.

Show child attributes

Example:

[
  {
    "role": "system",
    "content": "You are a concise assistant."
  },
  {
    "role": "user",
    "content": "Explain quantum entanglement in one sentence."
  }
]

stream

boolean

default:false

Whether to return the result as a stream (an SSE event stream terminated by data: [DONE]). Defaults to false.

Example:

false

max_completion_tokens

integer

Maximum number of tokens to generate (including reasoning tokens).

Note This model series uses max_completion_tokens. For backward compatibility, passing only max_tokens is automatically treated as max_completion_tokens; however, do not pass both fields at once — on gpt-5.1 / gpt-5.2 / gpt-5.4 passing both returns 400.

Example:

2048

reasoning_effort

enum<string>

Reasoning depth control. The allowed values vary by model:

Model	Allowed values
`gpt-5.6-sol` / `gpt-5.6-terra` / `gpt-5.6-luna` / `gpt-5.5`	`none`, `low`, `medium`, `high`, `xhigh`
`gpt-5.4` / `gpt-5.2` / `gpt-5.1`	`low`, `medium`, `high`, `xhigh`

Reasoning tokens are billed as output tokens and counted in usage.completion_tokens_details.reasoning_tokens.

Available options:

none,

low,

medium,

high,

xhigh

Example:

"medium"

verbosity

enum<string>

How detailed the answer should be: low / medium / high.

Note Supported only by gpt-5.6-sol / gpt-5.6-terra / gpt-5.6-luna / gpt-5.5; other models do not support this parameter.

Available options:

low,

medium,

high

Example:

"low"

temperature

number

Sampling temperature, ranging from 0 to 2. Lower values make the output more deterministic.

Note Supported only by gpt-5.5 / gpt-5.4 / gpt-5.2 / gpt-5.1. The gpt-5.6 family accepts only the default value 1; passing any other value returns 400.

Required range: 0 <= x <= 2

Example:

0.7

top_p

number

Nucleus sampling parameter, ranging from 0 to 1. Adjusting it together with temperature is not recommended.

Note Supported only by gpt-5.5 / gpt-5.4 / gpt-5.2 / gpt-5.1; the gpt-5.6 family does not support this parameter.

Required range: 0 <= x <= 1

Example:

0.9

frequency_penalty

number

Frequency penalty, ranging from -2 to 2. Positive values penalize tokens by how often they have appeared, reducing repeated content.

Note Supported only by gpt-5.4 / gpt-5.2 / gpt-5.1; the gpt-5.6 family and gpt-5.5 do not support this parameter.

Required range: -2 <= x <= 2

Example:

0.5

presence_penalty

number

Presence penalty, ranging from -2 to 2. Positive values encourage the model to talk about new topics.

Note Supported only by gpt-5.4 / gpt-5.2 / gpt-5.1; the gpt-5.6 family and gpt-5.5 do not support this parameter.

Required range: -2 <= x <= 2

Example:

0.5

logprobs

boolean

default:false

Whether to return the log probabilities of each output token.

Note Supported only by gpt-5.4 / gpt-5.2 / gpt-5.1; the gpt-5.6 family and gpt-5.5 do not support this parameter.

Example:

true

top_logprobs

integer

Number of candidate tokens returned at each position, ranging from 0 to 5; must be used together with logprobs: true.

Note Same model support as logprobs.

Required range: 0 <= x <= 5

Example:

2

integer

default:1

Number of candidate replies to generate, returned as multiple entries in the choices array. All tokens (including the output of every candidate) are billed.

Example:

1

seed

integer

Random seed. With the same seed and parameter combination, the model tries to return consistent results (best effort; full reproducibility is not guaranteed).

Example:

42

response_format

object

Output format control:

{"type": "text"}: free-form text, the default
{"type": "json_object"}: returns valid JSON, and requires the word json to appear in messages, otherwise 400 is returned
{"type": "json_schema", "json_schema": {...}}: returns structured output following the given JSON Schema; combine it with "strict": true to enforce conformance to the schema

Show child attributes

tools

object[]

Tool list, used for function calling (client-side function calls, no per-call fee).

Server-side tools (web search, code execution, and so on) are not provided on this API; use the Responses API instead.

Show child attributes

tool_choice

Tool choice control: "auto" (default) / "none" / "required", or an object naming a specific function, such as {"type": "function", "function": {"name": "get_weather"}}.

Available options:

none,

auto,

required

parallel_tool_calls

boolean

default:true

Whether the model may call multiple tools in parallel within one turn. Defaults to true; set it to false to force calls one at a time.

Example:

true

prompt_cache_key

string

Cache grouping key. Passing the same value for requests that share the same prefix improves the prompt cache hit rate.

Example:

"app-chat-v1"

user

string

End-user identifier, used to distinguish the source of calls.

Example:

"user-1024"

Response

Chat completion succeeded (a JSON object; when stream=true, an SSE event stream terminated by data: [DONE])

string

Unique identifier for this conversation

Example:

"chatcmpl-CvJ2p8mQxK7nR4wS"

object

enum<string>

Response type

Available options:

chat.completion

Example:

"chat.completion"

created

integer

Creation timestamp

Example:

1786705221

model

string

Actual model name used

Example:

"gpt-5.6-sol"

choices

object[]

List of generated results (length equals n in the request)

Show child attributes

usage

object

Token usage statistics. Prompt caching applies automatically, and cached input tokens are billed at the lower cached rate.

Show child attributes

Image Series

Video Series

Audio Series

Text Series

Account Management

Task Management

File Management

GPT All-Model API - Chat Completions Reference

Authorizations

Body

Response